Zásuvky

Sokety jsou technologie přenosu dat nízké úrovně, nad kterou se implementuje mnoho síťových protokolů. Windows nabízí třídy soketů TCP a UDP pro aplikace typu klient-server nebo peer-to-peer, bez ohledu na to, jestli připojení jsou dlouhodobá nebo navázáná připojení nejsou nutná.

Toto téma se zaměřuje na to, jak používat třídy soketů systému Windows, které jsou v oboru názvů Windows.Networking.Sockets. V aplikaci Windows ale můžete také použít Windows Sockets 2 (Winsock).

Note

v důsledku izolace sítě Windows neumožňuje navázat socketové připojení (Sockets nebo WinSock) mezi dvěma aplikacemi Windows běžícími na stejném počítači, ať už prostřednictvím adresy místní smyčky (127.0.0.1), nebo explicitním zadáním místní IP adresy. Podrobnosti o mechanismech, podle kterých můžou aplikace Windows vzájemně komunikovat, najdete v tématu Komunikace mezi aplikacemi.

Vytvoření základního klienta a serveru soketu TCP

Soket TCP (Transmission Control Protocol) poskytuje přenosy síťových dat nízké úrovně v obou směrech pro připojení, která jsou dlouhodobá. Sokety TCP jsou základní funkcí, kterou používá většina síťových protokolů používaných na internetu. Abychom si ukázali základní operace TCP, ukázkový kód níže ukazuje StreamSocket a StreamSocketListener odesílání a příjem dat přes TCP k vytvoření klienta echo a serveru.

Chcete-li začít s co nejmenším počtem součástí a prozatím se vyhnout problémům s izolací sítě, vytvořte nový projekt a vložte do něj níže uvedený klientský i serverový kód.

V projektu budete muset deklarovat funkci aplikace . Otevřete zdrojový soubor manifestu balíčku aplikace (soubor Package.appxmanifest) a na kartě Možnosti zaškrtněte možnost Privátní sítě (klient a server). Takto to vypadá v Package.appxmanifest kódu.

<Capability Name="privateNetworkClientServer" />

privateNetworkClientServerMísto toho můžete deklarovatinternetClientServer, jestli se připojujete přes internet. StreamSocket i StreamSocketListener potřebují jednu nebo druhou z těchto funkcí aplikace, které se mají deklarovat.

Echo klient a server využívající sokety TCP

Vytvořte StreamSocketListener a začněte naslouchat příchozím TCP připojením. Událost StreamSocketListener.ConnectionReceived se vyvolá pokaždé, když klient vytvoří připojení ke streamSocketListener.

Vytvořte také StreamSocket, vytvořte připojení k serveru, odešlete požadavek a obdržíte odpověď.

Vytvořte novou stránku s názvem StreamSocketAndListenerPage. Vložte značky XAML do StreamSocketAndListenerPage.xaml a imperativní kód vložte do třídy StreamSocketAndListenerPage.

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>

    <StackPanel>
        <TextBlock Margin="9.6,0" Style="{StaticResource TitleTextBlockStyle}" Text="TCP socket example"/>
        <TextBlock Margin="7.2,0,0,0" Style="{StaticResource HeaderTextBlockStyle}" Text="StreamSocket &amp; StreamSocketListener"/>
    </StackPanel>

    <Grid Grid.Row="1">
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <TextBlock Margin="9.6" Style="{StaticResource SubtitleTextBlockStyle}" Text="client"/>
        <ListBox x:Name="clientListBox" Grid.Row="1" Margin="9.6"/>
        <TextBlock Grid.Column="1" Margin="9.6" Style="{StaticResource SubtitleTextBlockStyle}" Text="server"/>
        <ListBox x:Name="serverListBox" Grid.Column="1" Grid.Row="1" Margin="9.6"/>
    </Grid>
</Grid>

// Every protocol typically has a standard port number. For example, HTTP is typically 80, FTP is 20 and 21, etc.
// For this example, we'll choose an arbitrary port number.
static string PortNumber = "1337";

protected override void OnNavigatedTo(NavigationEventArgs e)
{
    this.StartServer();
    this.StartClient();
}

private async void StartServer()
{
    try
    {
        var streamSocketListener = new Windows.Networking.Sockets.StreamSocketListener();

        // The ConnectionReceived event is raised when connections are received.
        streamSocketListener.ConnectionReceived += this.StreamSocketListener_ConnectionReceived;

        // Start listening for incoming TCP connections on the specified port. You can specify any port that's not currently in use.
        await streamSocketListener.BindServiceNameAsync(StreamSocketAndListenerPage.PortNumber);

        this.serverListBox.Items.Add("server is listening...");
    }
    catch (Exception ex)
    {
        Windows.Networking.Sockets.SocketErrorStatus webErrorStatus = Windows.Networking.Sockets.SocketError.GetStatus(ex.GetBaseException().HResult);
        this.serverListBox.Items.Add(webErrorStatus.ToString() != "Unknown" ? webErrorStatus.ToString() : ex.Message);
    }
}

private async void StreamSocketListener_ConnectionReceived(Windows.Networking.Sockets.StreamSocketListener sender, Windows.Networking.Sockets.StreamSocketListenerConnectionReceivedEventArgs args)
{
    string request;
    using (var streamReader = new StreamReader(args.Socket.InputStream.AsStreamForRead()))
    {
        request = await streamReader.ReadLineAsync();
    }

    DispatcherQueue.TryEnqueue(() => this.serverListBox.Items.Add(string.Format("server received the request: \"{0}\"", request)));

    // Echo the request back as the response.
    using (Stream outputStream = args.Socket.OutputStream.AsStreamForWrite())
    {
        using (var streamWriter = new StreamWriter(outputStream))
        {
            await streamWriter.WriteLineAsync(request);
            await streamWriter.FlushAsync();
        }
    }

    DispatcherQueue.TryEnqueue(() => this.serverListBox.Items.Add(string.Format("server sent back the response: \"{0}\"", request)));

    sender.Dispose();

    DispatcherQueue.TryEnqueue(() => this.serverListBox.Items.Add("server closed its socket"));
}

private async void StartClient()
{
    try
    {
        // Create the StreamSocket and establish a connection to the echo server.
        using (var streamSocket = new Windows.Networking.Sockets.StreamSocket())
        {
            // The server hostname that we will be establishing a connection to. In this example, the server and client are in the same process.
            var hostName = new Windows.Networking.HostName("localhost");

            this.clientListBox.Items.Add("client is trying to connect...");

            await streamSocket.ConnectAsync(hostName, StreamSocketAndListenerPage.PortNumber);

            this.clientListBox.Items.Add("client connected");

            // Send a request to the echo server.
            string request = "Hello, World!";
            using (Stream outputStream = streamSocket.OutputStream.AsStreamForWrite())
            {
                using (var streamWriter = new StreamWriter(outputStream))
                {
                    await streamWriter.WriteLineAsync(request);
                    await streamWriter.FlushAsync();
                }
            }

            this.clientListBox.Items.Add(string.Format("client sent the request: \"{0}\"", request));

            // Read data from the echo server.
            string response;
            using (Stream inputStream = streamSocket.InputStream.AsStreamForRead())
            {
                using (StreamReader streamReader = new StreamReader(inputStream))
                {
                    response = await streamReader.ReadLineAsync();
                }
            }

            this.clientListBox.Items.Add(string.Format("client received the response: \"{0}\" ", response));
        }

        this.clientListBox.Items.Add("client closed its socket");
    }
    catch (Exception ex)
    {
        Windows.Networking.Sockets.SocketErrorStatus webErrorStatus = Windows.Networking.Sockets.SocketError.GetStatus(ex.GetBaseException().HResult);
        this.clientListBox.Items.Add(webErrorStatus.ToString() != "Unknown" ? webErrorStatus.ToString() : ex.Message);
    }
}

#include <winrt/Windows.Foundation.h>
#include <winrt/Windows.Networking.Sockets.h>
#include <winrt/Windows.Storage.Streams.h>
#include <winrt/Microsoft.UI.Dispatching.h>
#include <winrt/Microsoft.UI.Xaml.Navigation.h>
#include <sstream>

using namespace winrt;
using namespace Windows::Foundation;
using namespace Windows::Storage::Streams;
using namespace Microsoft::UI::Dispatching;
using namespace Microsoft::UI::Xaml::Navigation;
...
private:
    Windows::Networking::Sockets::StreamSocketListener m_streamSocketListener;
    Windows::Networking::Sockets::StreamSocket m_streamSocket;

public:
    void OnNavigatedTo(NavigationEventArgs const& /* e */)
    {
        StartServer();
        StartClient();
    }

private:
    IAsyncAction StartServer()
    {
        try
        {
            // The ConnectionReceived event is raised when connections are received.
            m_streamSocketListener.ConnectionReceived({ this, &StreamSocketAndListenerPage::OnConnectionReceived });

            // Start listening for incoming TCP connections on the specified port. You can specify any port that's not currently in use.
            // Every protocol typically has a standard port number. For example, HTTP is typically 80, FTP is 20 and 21, etc.
            // For this example, we'll choose an arbitrary port number.
            co_await m_streamSocketListener.BindServiceNameAsync(L"1337");
            serverListBox().Items().Append(winrt::box_value(L"server is listening..."));
        }
        catch (winrt::hresult_error const& ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus{ Windows::Networking::Sockets::SocketError::GetStatus(ex.to_abi()) };
            serverListBox().Items().Append(webErrorStatus != Windows::Networking::Sockets::SocketErrorStatus::Unknown ? winrt::box_value(winrt::to_hstring((int32_t)webErrorStatus)) : winrt::box_value(winrt::to_hstring(ex.to_abi())));
        }
    }

    IAsyncAction OnConnectionReceived(Windows::Networking::Sockets::StreamSocketListener /* sender */, Windows::Networking::Sockets::StreamSocketListenerConnectionReceivedEventArgs args)
    {
        try
        {
            auto socket{ args.Socket() }; // Keep the socket referenced, and alive.
            DataReader dataReader{ socket.InputStream() };

            unsigned int bytesLoaded = co_await dataReader.LoadAsync(sizeof(unsigned int));

            unsigned int stringLength = dataReader.ReadUInt32();
            bytesLoaded = co_await dataReader.LoadAsync(stringLength);
            winrt::hstring request = dataReader.ReadString(bytesLoaded);

            serverListBox().DispatcherQueue().TryEnqueue([=]()
            {
                std::wstringstream wstringstream;
                wstringstream << L"server received the request: \"" << request.c_str() << L"\"";
                serverListBox().Items().Append(winrt::box_value(wstringstream.str().c_str()));
            });

            // Echo the request back as the response.
            DataWriter dataWriter{ socket.OutputStream() };
            dataWriter.WriteUInt32(request.size());
            dataWriter.WriteString(request);
            co_await dataWriter.StoreAsync();
            dataWriter.DetachStream();

            serverListBox().DispatcherQueue().TryEnqueue([=]()
            {
                std::wstringstream wstringstream;
                wstringstream << L"server sent back the response: \"" << request.c_str() << L"\"";
                serverListBox().Items().Append(winrt::box_value(wstringstream.str().c_str()));
            });

            m_streamSocketListener = nullptr;

            serverListBox().DispatcherQueue().TryEnqueue([=]()
            {
                serverListBox().Items().Append(winrt::box_value(L"server closed its socket"));
            });
        }
        catch (winrt::hresult_error const& ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus{ Windows::Networking::Sockets::SocketError::GetStatus(ex.to_abi()) };
            serverListBox().DispatcherQueue().TryEnqueue([=]()
            {
                serverListBox().Items().Append(webErrorStatus != Windows::Networking::Sockets::SocketErrorStatus::Unknown ? winrt::box_value(winrt::to_hstring((int32_t)webErrorStatus)) : winrt::box_value(winrt::to_hstring(ex.to_abi())));
            });
        }
    }

    IAsyncAction StartClient()
    {
        try
        {
            // Establish a connection to the echo server.

            // The server hostname that we will be establishing a connection to. In this example, the server and client are in the same process.
            Windows::Networking::HostName hostName{ L"localhost" };

            clientListBox().Items().Append(winrt::box_value(L"client is trying to connect..."));

            co_await m_streamSocket.ConnectAsync(hostName, L"1337");
            clientListBox().Items().Append(winrt::box_value(L"client connected"));

            // Send a request to the echo server.
            DataWriter dataWriter{ m_streamSocket.OutputStream() };
            winrt::hstring request{ L"Hello, World!" };
            dataWriter.WriteUInt32(request.size());
            dataWriter.WriteString(request);

            co_await dataWriter.StoreAsync();

            std::wstringstream wstringstream;
            wstringstream << L"client sent the request: \"" << request.c_str() << L"\"";
            clientListBox().Items().Append(winrt::box_value(wstringstream.str().c_str()));

            co_await dataWriter.FlushAsync();
            dataWriter.DetachStream();

            // Read data from the echo server.
            DataReader dataReader{ m_streamSocket.InputStream() };
            unsigned int bytesLoaded = co_await dataReader.LoadAsync(sizeof(unsigned int));
            unsigned int stringLength = dataReader.ReadUInt32();
            bytesLoaded = co_await dataReader.LoadAsync(stringLength);
            winrt::hstring response{ dataReader.ReadString(bytesLoaded) };

            wstringstream.str(L"");
            wstringstream << L"client received the response: \"" << response.c_str() << L"\"";
            clientListBox().Items().Append(winrt::box_value(wstringstream.str().c_str()));

            m_streamSocket = nullptr;

            clientListBox().Items().Append(winrt::box_value(L"client closed its socket"));
        }
        catch (winrt::hresult_error const& ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus{ Windows::Networking::Sockets::SocketError::GetStatus(ex.to_abi()) };
            serverListBox().Items().Append(webErrorStatus != Windows::Networking::Sockets::SocketErrorStatus::Unknown ? winrt::box_value(winrt::to_hstring((int32_t)webErrorStatus)) : winrt::box_value(winrt::to_hstring(ex.to_abi())));
        }
    }

#include <ppltasks.h>
#include <sstream>
...
using namespace Windows::Foundation;
using namespace Windows::Storage::Streams;
using namespace Windows::UI::Core;
using namespace Windows::UI::Xaml::Navigation;
...
private:
    Windows::Networking::Sockets::StreamSocketListener^ streamSocketListener;
    Windows::Networking::Sockets::StreamSocket^ streamSocket;

protected:
    virtual void OnNavigatedTo(NavigationEventArgs^ e) override
    {
        this->StartServer();
        this->StartClient();
    }

private:
    void StartServer()
    {
        try
        {
            this->streamSocketListener = ref new Windows::Networking::Sockets::StreamSocketListener();

            // The ConnectionReceived event is raised when connections are received.
            streamSocketListener->ConnectionReceived += ref new TypedEventHandler<Windows::Networking::Sockets::StreamSocketListener^, Windows::Networking::Sockets::StreamSocketListenerConnectionReceivedEventArgs^>(this, &StreamSocketAndListenerPage::StreamSocketListener_ConnectionReceived);

            // Start listening for incoming TCP connections on the specified port. You can specify any port that's not currently in use.
            // Every protocol typically has a standard port number. For example, HTTP is typically 80, FTP is 20 and 21, etc.
            // For this example, we'll choose an arbitrary port number.
            Concurrency::create_task(streamSocketListener->BindServiceNameAsync(L"1337")).then(
                [=]
            {
                this->serverListBox->Items->Append(L"server is listening...");
            });
        }
        catch (Platform::Exception^ ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus = Windows::Networking::Sockets::SocketError::GetStatus(ex->HResult);
            this->serverListBox->Items->Append(webErrorStatus.ToString() != L"Unknown" ? webErrorStatus.ToString() : ex->Message);
        }
    }

    void StreamSocketListener_ConnectionReceived(Windows::Networking::Sockets::StreamSocketListener^ sender, Windows::Networking::Sockets::StreamSocketListenerConnectionReceivedEventArgs^ args)
    {
        try
        {
            auto dataReader = ref new DataReader(args->Socket->InputStream);

            Concurrency::create_task(dataReader->LoadAsync(sizeof(unsigned int))).then(
                [=](unsigned int bytesLoaded)
            {
                unsigned int stringLength = dataReader->ReadUInt32();
                Concurrency::create_task(dataReader->LoadAsync(stringLength)).then(
                    [=](unsigned int bytesLoaded)
                {
                    Platform::String^ request = dataReader->ReadString(bytesLoaded);
                    this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler(
                        [=]
                    {
                        std::wstringstream wstringstream;
                        wstringstream << L"server received the request: \"" << request->Data() << L"\"";
                        this->serverListBox->Items->Append(ref new Platform::String(wstringstream.str().c_str()));
                    }));

                    // Echo the request back as the response.
                    auto dataWriter = ref new DataWriter(args->Socket->OutputStream);
                    dataWriter->WriteUInt32(request->Length());
                    dataWriter->WriteString(request);
                    Concurrency::create_task(dataWriter->StoreAsync()).then(
                        [=](unsigned int)
                    {
                        dataWriter->DetachStream();

                        this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler(
                            [=]()
                        {
                            std::wstringstream wstringstream;
                            wstringstream << L"server sent back the response: \"" << request->Data() << L"\"";
                            this->serverListBox->Items->Append(ref new Platform::String(wstringstream.str().c_str()));
                        }));

                        delete this->streamSocketListener;
                        this->streamSocketListener = nullptr;

                        this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler([=]() {this->serverListBox->Items->Append(L"server closed its socket"); }));
                    });
                });
            });
        }
        catch (Platform::Exception^ ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus = Windows::Networking::Sockets::SocketError::GetStatus(ex->HResult);
            this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler([=]() {this->serverListBox->Items->Append(webErrorStatus.ToString() != L"Unknown" ? webErrorStatus.ToString() : ex->Message); }));
        }
    }

    void StartClient()
    {
        try
        {
            // Create the StreamSocket and establish a connection to the echo server.
            this->streamSocket = ref new Windows::Networking::Sockets::StreamSocket();

            // The server hostname that we will be establishing a connection to. In this example, the server and client are in the same process.
            auto hostName = ref new Windows::Networking::HostName(L"localhost");

            this->clientListBox->Items->Append(L"client is trying to connect...");

            Concurrency::create_task(this->streamSocket->ConnectAsync(hostName, L"1337")).then(
                [=](Concurrency::task< void >)
            {
                this->clientListBox->Items->Append(L"client connected");

                // Send a request to the echo server.
                auto dataWriter = ref new DataWriter(this->streamSocket->OutputStream);
                auto request = ref new Platform::String(L"Hello, World!");
                dataWriter->WriteUInt32(request->Length());
                dataWriter->WriteString(request);

                Concurrency::create_task(dataWriter->StoreAsync()).then(
                    [=](Concurrency::task< unsigned int >)
                {
                    std::wstringstream wstringstream;
                    wstringstream << L"client sent the request: \"" << request->Data() << L"\"";
                    this->clientListBox->Items->Append(ref new Platform::String(wstringstream.str().c_str()));

                    Concurrency::create_task(dataWriter->FlushAsync()).then(
                        [=](Concurrency::task< bool >)
                    {
                        dataWriter->DetachStream();

                        // Read data from the echo server.
                        auto dataReader = ref new DataReader(this->streamSocket->InputStream);
                        Concurrency::create_task(dataReader->LoadAsync(sizeof(unsigned int))).then(
                            [=](unsigned int bytesLoaded)
                        {
                            unsigned int stringLength = dataReader->ReadUInt32();
                            Concurrency::create_task(dataReader->LoadAsync(stringLength)).then(
                                [=](unsigned int bytesLoaded)
                            {
                                Platform::String^ response = dataReader->ReadString(bytesLoaded);
                                this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler(
                                    [=]
                                {
                                    std::wstringstream wstringstream;
                                    wstringstream << L"client received the response: \"" << response->Data() << L"\"";
                                    this->clientListBox->Items->Append(ref new Platform::String(wstringstream.str().c_str()));

                                    delete this->streamSocket;
                                    this->streamSocket = nullptr;

                                    this->clientListBox->Items->Append(L"client closed its socket");
                                }));
                            });
                        });
                    });
                });
            });
        }
        catch (Platform::Exception^ ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus = Windows::Networking::Sockets::SocketError::GetStatus(ex->HResult);
            this->serverListBox->Items->Append(webErrorStatus.ToString() != L"Unknown" ? webErrorStatus.ToString() : ex->Message);
        }
    }

Odkazy na streamSockety v pokračováních C++ PPL (platí pro C++/CX, primárně)

Note

Pokud používáte coroutiny C++/WinRT a předáte parametry podle hodnoty, pak se tento problém nepoužije. Doporučení pro předávání parametrů najdete v tématu Souběžnost a asynchronní operace s C++/WinRT.

StreamSocket zůstane aktivní, pokud je aktivní čtení a zápis ve vstupním/výstupním datovém proudu (například StreamSocketListenerConnectionReceivedEventArgs.Socket, ke kterému máte přístup v obslužné rutině události StreamSocketListener.ConnectionReceived). Při volání DataReader.LoadAsync (nebo ReadAsync/WriteAsync/StoreAsync) se podrží odkaz na soket (prostřednictvím vstupního proudu soketu), dokud se nedokončí vykonávání obslužné rutiny události Completed (pokud nějaká existuje) operace LoadAsync.

Knihovna PPL (Parallel Patterns Library) ve výchozím nastavení neplánuje pokračování úkolů. Jinými slovy, přidání úlohy pokračování (s task::then()) nezaručuje, že se úloha pokračování spustí jako obslužná rutina dokončení.

void StreamSocketListener_ConnectionReceived(Windows::Networking::Sockets::StreamSocketListener^ sender, Windows::Networking::Sockets::StreamSocketListenerConnectionReceivedEventArgs^ args)
{
    auto dataReader = ref new DataReader(args->Socket->InputStream);
    Concurrency::create_task(dataReader->LoadAsync(sizeof(unsigned int))).then(
        [=](unsigned int bytesLoaded)
    {
        // Work in here isn't guaranteed to execute inline as the completion handler of the LoadAsync.
    });
}

Z pohledu StreamSocket obslužná rutina dokončení již dokončila provádění (a soket lze uvolnit) ještě před spuštěním těla pokračování. Pokud tedy chcete zabránit tomu, aby byl socket uvolněn, když ho chcete použít uvnitř daného pokračování, musíte buď přímo odkazovat na socket (pomocí zachycení v lambda výrazu) a použít ho, nebo nepřímo (tím, že budete v pokračováních nadále přistupovat k args->Socket), anebo vynutit, aby se úlohy pokračování spouštěly inline. První techniku (zachycení lambda) můžete vidět v akci v ukázce StreamSocketu. Kód C++/CX v oddílu Vytvoření základního klienta a serveru TCP socketu uvedeném výše používá druhou techniku – vrací požadavek jako odpověď a přistupuje k args->Socket z jednoho z nejvnitřnějších pokračování.

Třetí technika je vhodná v případě, že nereagujete zpět na odpověď. Pomocí task_continuation_context::use_synchronous_execution() této možnosti vynutíte, aby PPL spustil text pokračování v textu. Tady je příklad kódu, který ukazuje, jak to udělat.

void StreamSocketListener_ConnectionReceived(Windows::Networking::Sockets::StreamSocketListener^ sender, Windows::Networking::Sockets::StreamSocketListenerConnectionReceivedEventArgs^ args)
{
    auto dataReader = ref new DataReader(args->Socket->InputStream);

    Concurrency::create_task(dataReader->LoadAsync(sizeof(unsigned int))).then(
        [=](unsigned int bytesLoaded)
    {
        unsigned int messageLength = dataReader->ReadUInt32();
        Concurrency::create_task(dataReader->LoadAsync(messageLength)).then(
            [=](unsigned int bytesLoaded)
        {
            Platform::String^ request = dataReader->ReadString(bytesLoaded);
            this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler(
                [=]
            {
                std::wstringstream wstringstream;
                wstringstream << L"server received the request: \"" << request->Data() << L"\"";
                this->serverListBox->Items->Append(ref new Platform::String(wstringstream.str().c_str()));
            }));
        });
    }, Concurrency::task_continuation_context::use_synchronous_execution());
}

Toto chování se vztahuje na všechny třídy Sockets a WebSockets v oboru názvů Windows.Networking.Sockets. Scénáře na straně klienta ale obvykle ukládají sokety do členských proměnných, takže problém je nejvhodnější pro scénář StreamSocketListener.ConnectionReceived , jak je znázorněno výše.

Vytvoření základního klienta soketu UDP a serveru

Soket UDP (User Datagram Protocol) je podobný soketu TCP, který také poskytuje přenosy síťových dat nízké úrovně v obou směrech. Zatímco je soket TCP pro dlouhodobá připojení, soket UDP je určen pro aplikace, u kterých není nutné navazované připojení. Protože sokety UDP neudržují připojení na obou koncových bodech, představují rychlé a jednoduché řešení pro sítě mezi vzdálenými počítači. Ale sokety UDP nezaručují integritu síťových paketů ani to, zda pakety vůbec dorazí do vzdáleného cíle. Aplikace proto bude muset být navržená tak, aby tolerovala. Mezi příklady aplikací, které používají sokety UDP, patří zjišťování místní sítě a místní chatovací klienti.

Abychom si ukázali základní operace UDP, ukázkový kód níže ukazuje třídu DatagramSocket , která se používá k odesílání a přijímání dat přes UDP k vytvoření klienta echo a serveru. Vytvořte nový projekt a vložte kód klienta i serveru níže do stejného projektu. Stejně jako u soketu TCP budete muset deklarovat funkci aplikace Privátní sítě (klient &server ).

Klient odezvy a server používající sokety UDP

Vytvořte DatagramSocket, který bude fungovat jako server echo, přidružte jej ke konkrétnímu číslu portu, naslouchejte příchozí zprávě UDP a odešlete ji zpět. Událost DatagramSocket.MessageReceived je vyvolána při přijetí zprávy na soketu.

Vytvořte další DatagramSocket, který bude fungovat jako echo klient, navažte ho na konkrétní číslo portu, odešlete zprávu UDP a přijměte odpověď.

Vytvořte novou stránku s názvem DatagramSocketPage. Vložte značky XAML do DatagramSocketPage.xaml a imperativní kód vložte do třídy DatagramSocketPage.

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>

    <StackPanel>
        <TextBlock Margin="9.6,0" Style="{StaticResource TitleTextBlockStyle}" Text="UDP socket example"/>
        <TextBlock Margin="7.2,0,0,0" Style="{StaticResource HeaderTextBlockStyle}" Text="DatagramSocket"/>
    </StackPanel>

    <Grid Grid.Row="1">
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <TextBlock Margin="9.6" Style="{StaticResource SubtitleTextBlockStyle}" Text="client"/>
        <ListBox x:Name="clientListBox" Grid.Row="1" Margin="9.6"/>
        <TextBlock Grid.Column="1" Margin="9.6" Style="{StaticResource SubtitleTextBlockStyle}" Text="server"/>
        <ListBox x:Name="serverListBox" Grid.Column="1" Grid.Row="1" Margin="9.6"/>
    </Grid>
</Grid>

// Every protocol typically has a standard port number. For example, HTTP is typically 80, FTP is 20 and 21, etc.
// For this example, we'll choose different arbitrary port numbers for client and server, since both will be running on the same machine.
static string ClientPortNumber = "1336";
static string ServerPortNumber = "1337";

protected override void OnNavigatedTo(NavigationEventArgs e)
{
    this.StartServer();
    this.StartClient();
}

private async void StartServer()
{
    try
    {
        var serverDatagramSocket = new Windows.Networking.Sockets.DatagramSocket();

        // The ConnectionReceived event is raised when connections are received.
        serverDatagramSocket.MessageReceived += ServerDatagramSocket_MessageReceived;

        this.serverListBox.Items.Add("server is about to bind...");

        // Start listening for incoming UDP datagrams on the specified port. You can specify any port that's not currently in use.
        await serverDatagramSocket.BindServiceNameAsync(DatagramSocketPage.ServerPortNumber);

        this.serverListBox.Items.Add(string.Format("server is bound to port number {0}", DatagramSocketPage.ServerPortNumber));
    }
    catch (Exception ex)
    {
        Windows.Networking.Sockets.SocketErrorStatus webErrorStatus = Windows.Networking.Sockets.SocketError.GetStatus(ex.GetBaseException().HResult);
        this.serverListBox.Items.Add(webErrorStatus.ToString() != "Unknown" ? webErrorStatus.ToString() : ex.Message);
    }
}

private async void ServerDatagramSocket_MessageReceived(Windows.Networking.Sockets.DatagramSocket sender, Windows.Networking.Sockets.DatagramSocketMessageReceivedEventArgs args)
{
    string request;
    using (DataReader dataReader = args.GetDataReader())
    {
        request = dataReader.ReadString(dataReader.UnconsumedBufferLength).Trim();
    }

    DispatcherQueue.TryEnqueue(() => this.serverListBox.Items.Add(string.Format("server received the request: \"{0}\"", request)));

    // Echo the request back as the response.
    using (Stream outputStream = (await sender.GetOutputStreamAsync(args.RemoteAddress, DatagramSocketPage.ClientPortNumber)).AsStreamForWrite())
    {
        using (var streamWriter = new StreamWriter(outputStream))
        {
            await streamWriter.WriteLineAsync(request);
            await streamWriter.FlushAsync();
        }
    }

    DispatcherQueue.TryEnqueue(() => this.serverListBox.Items.Add(string.Format("server sent back the response: \"{0}\"", request)));

    sender.Dispose();

    DispatcherQueue.TryEnqueue(() => this.serverListBox.Items.Add("server closed its socket"));
}

private async void StartClient()
{
    try
    {
        // Create the DatagramSocket and establish a connection to the echo server.
        var clientDatagramSocket = new Windows.Networking.Sockets.DatagramSocket();

        clientDatagramSocket.MessageReceived += ClientDatagramSocket_MessageReceived;

        // The server hostname that we will be establishing a connection to. In this example, the server and client are in the same process.
        var hostName = new Windows.Networking.HostName("localhost");

        this.clientListBox.Items.Add("client is about to bind...");

        await clientDatagramSocket.BindServiceNameAsync(DatagramSocketPage.ClientPortNumber);

        this.clientListBox.Items.Add(string.Format("client is bound to port number {0}", DatagramSocketPage.ClientPortNumber));

        // Send a request to the echo server.
        string request = "Hello, World!";
        using (var serverDatagramSocket = new Windows.Networking.Sockets.DatagramSocket())
        {
            using (Stream outputStream = (await serverDatagramSocket.GetOutputStreamAsync(hostName, DatagramSocketPage.ServerPortNumber)).AsStreamForWrite())
            {
                using (var streamWriter = new StreamWriter(outputStream))
                {
                    await streamWriter.WriteLineAsync(request);
                    await streamWriter.FlushAsync();
                }
            }
        }

        this.clientListBox.Items.Add(string.Format("client sent the request: \"{0}\"", request));
    }
    catch (Exception ex)
    {
        Windows.Networking.Sockets.SocketErrorStatus webErrorStatus = Windows.Networking.Sockets.SocketError.GetStatus(ex.GetBaseException().HResult);
        this.clientListBox.Items.Add(webErrorStatus.ToString() != "Unknown" ? webErrorStatus.ToString() : ex.Message);
    }
}

private async void ClientDatagramSocket_MessageReceived(Windows.Networking.Sockets.DatagramSocket sender, Windows.Networking.Sockets.DatagramSocketMessageReceivedEventArgs args)
{
    string response;
    using (DataReader dataReader = args.GetDataReader())
    {
        response = dataReader.ReadString(dataReader.UnconsumedBufferLength).Trim();
    }

    DispatcherQueue.TryEnqueue(() => this.clientListBox.Items.Add(string.Format("client received the response: \"{0}\"", response)));

    sender.Dispose();

    DispatcherQueue.TryEnqueue(() => this.clientListBox.Items.Add("client closed its socket"));
}

#include <winrt/Windows.Foundation.h>
#include <winrt/Windows.Networking.Sockets.h>
#include <winrt/Windows.Storage.Streams.h>
#include <winrt/Microsoft.UI.Dispatching.h>
#include <winrt/Microsoft.UI.Xaml.Navigation.h>
#include <sstream>

using namespace winrt;
using namespace Windows::Foundation;
using namespace Windows::Storage::Streams;
using namespace Microsoft::UI::Dispatching;
using namespace Microsoft::UI::Xaml::Navigation;
...
private:
    Windows::Networking::Sockets::DatagramSocket m_clientDatagramSocket;
    Windows::Networking::Sockets::DatagramSocket m_serverDatagramSocket;

public:
    void OnNavigatedTo(NavigationEventArgs const& /* e */)
    {
        StartServer();
        StartClient();
    }

private:
    IAsyncAction StartServer()
    {
        try
        {
            // The ConnectionReceived event is raised when connections are received.
            m_serverDatagramSocket.MessageReceived({ this, &DatagramSocketPage::ServerDatagramSocket_MessageReceived });

            serverListBox().Items().Append(winrt::box_value(L"server is about to bind..."));

            // Start listening for incoming UDP datagrams on the specified port. You can specify any port that's not currently in use.
            co_await m_serverDatagramSocket.BindServiceNameAsync(L"1337");
            serverListBox().Items().Append(winrt::box_value(L"server is bound to port number 1337"));
        }
        catch (winrt::hresult_error const& ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus{ Windows::Networking::Sockets::SocketError::GetStatus(ex.to_abi()) };
            serverListBox().Items().Append(webErrorStatus != Windows::Networking::Sockets::SocketErrorStatus::Unknown ? winrt::box_value(winrt::to_hstring((int32_t)webErrorStatus)) : winrt::box_value(winrt::to_hstring(ex.to_abi())));
        }
    }

    IAsyncAction ServerDatagramSocket_MessageReceived(Windows::Networking::Sockets::DatagramSocket sender, Windows::Networking::Sockets::DatagramSocketMessageReceivedEventArgs args)
    {
        DataReader dataReader{ args.GetDataReader() };
        winrt::hstring request{ dataReader.ReadString(dataReader.UnconsumedBufferLength()) };

        serverListBox().DispatcherQueue().TryEnqueue([=]()
        {
            std::wstringstream wstringstream;
            wstringstream << L"server received the request: \"" << request.c_str() << L"\"";
            serverListBox().Items().Append(winrt::box_value(wstringstream.str().c_str()));
        });

        // Echo the request back as the response.
        IOutputStream outputStream = co_await sender.GetOutputStreamAsync(args.RemoteAddress(), L"1336");
        DataWriter dataWriter{ outputStream };
        dataWriter.WriteString(request);

        co_await dataWriter.StoreAsync();
        dataWriter.DetachStream();

        serverListBox().DispatcherQueue().TryEnqueue([=]()
        {
            std::wstringstream wstringstream;
            wstringstream << L"server sent back the response: \"" << request.c_str() << L"\"";
            serverListBox().Items().Append(winrt::box_value(wstringstream.str().c_str()));

            m_serverDatagramSocket = nullptr;

            serverListBox().Items().Append(winrt::box_value(L"server closed its socket"));
        });
    }

    IAsyncAction StartClient()
    {
        try
        {
            m_clientDatagramSocket.MessageReceived({ this, &DatagramSocketPage::ClientDatagramSocket_MessageReceived });

            // Establish a connection to the echo server.
            // The server hostname that we will be establishing a connection to. In this example, the server and client are in the same process.
            Windows::Networking::HostName hostName{ L"localhost" };

            clientListBox().Items().Append(winrt::box_value(L"client is about to bind..."));

            co_await m_clientDatagramSocket.BindServiceNameAsync(L"1336");
            clientListBox().Items().Append(winrt::box_value(L"client is bound to port number 1336"));

            // Send a request to the echo server.
            IOutputStream outputStream = co_await m_clientDatagramSocket.GetOutputStreamAsync(hostName, L"1337");

            winrt::hstring request{ L"Hello, World!" };
            DataWriter dataWriter{ outputStream };
            dataWriter.WriteString(request);
            co_await dataWriter.StoreAsync();
            dataWriter.DetachStream();

            std::wstringstream wstringstream;
            wstringstream << L"client sent the request: \"" << request.c_str() << L"\"";
            clientListBox().Items().Append(winrt::box_value(wstringstream.str().c_str()));
        }
        catch (winrt::hresult_error const& ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus{ Windows::Networking::Sockets::SocketError::GetStatus(ex.to_abi()) };
            serverListBox().Items().Append(webErrorStatus != Windows::Networking::Sockets::SocketErrorStatus::Unknown ? winrt::box_value(winrt::to_hstring((int32_t)webErrorStatus)) : winrt::box_value(winrt::to_hstring(ex.to_abi())));
        }
    }

    void ClientDatagramSocket_MessageReceived(Windows::Networking::Sockets::DatagramSocket const& /* sender */, Windows::Networking::Sockets::DatagramSocketMessageReceivedEventArgs const& args)
    {
        DataReader dataReader{ args.GetDataReader() };
        winrt::hstring response{ dataReader.ReadString(dataReader.UnconsumedBufferLength()) };
        clientListBox().DispatcherQueue().TryEnqueue([=]()
        {
            std::wstringstream wstringstream;
            wstringstream << L"client received the response: \"" << response.c_str() << L"\"";
            clientListBox().Items().Append(winrt::box_value(wstringstream.str().c_str()));
        });

        m_clientDatagramSocket = nullptr;

        clientListBox().DispatcherQueue().TryEnqueue([=]()
        {
            clientListBox().Items().Append(winrt::box_value(L"client closed its socket"));
        });
    }

#include <ppltasks.h>
#include <sstream>
...
using namespace Windows::Foundation;
using namespace Windows::Storage::Streams;
using namespace Windows::UI::Core;
using namespace Windows::UI::Xaml::Navigation;
...
private:
    Windows::Networking::Sockets::DatagramSocket^ clientDatagramSocket;
    Windows::Networking::Sockets::DatagramSocket^ serverDatagramSocket;

protected:
    virtual void OnNavigatedTo(NavigationEventArgs^ e) override
    {
        this->StartServer();
        this->StartClient();
    }

private:
    void StartServer()
    {
        try
        {
            this->serverDatagramSocket = ref new Windows::Networking::Sockets::DatagramSocket();

            // The ConnectionReceived event is raised when connections are received.
            this->serverDatagramSocket->MessageReceived += ref new TypedEventHandler<Windows::Networking::Sockets::DatagramSocket^, Windows::Networking::Sockets::DatagramSocketMessageReceivedEventArgs^>(this, &DatagramSocketPage::ServerDatagramSocket_MessageReceived);

            this->serverListBox->Items->Append(L"server is about to bind...");

            // Start listening for incoming UDP datagrams on the specified port. You can specify any port that's not currently in use.
            Concurrency::create_task(this->serverDatagramSocket->BindServiceNameAsync("1337")).then(
                [=]
            {
                this->serverListBox->Items->Append(L"server is bound to port number 1337");
            });
        }
        catch (Platform::Exception^ ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus = Windows::Networking::Sockets::SocketError::GetStatus(ex->HResult);
            this->serverListBox->Items->Append(webErrorStatus.ToString() != L"Unknown" ? webErrorStatus.ToString() : ex->Message);
        }
    }

    void ServerDatagramSocket_MessageReceived(Windows::Networking::Sockets::DatagramSocket^ sender, Windows::Networking::Sockets::DatagramSocketMessageReceivedEventArgs^ args)
    {
        DataReader^ dataReader = args->GetDataReader();
        Platform::String^ request = dataReader->ReadString(dataReader->UnconsumedBufferLength);
        this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler(
            [=]
        {
            std::wstringstream wstringstream;
            wstringstream << L"server received the request: \"" << request->Data() << L"\"";
            this->serverListBox->Items->Append(ref new Platform::String(wstringstream.str().c_str()));
        }));

        // Echo the request back as the response.
        Concurrency::create_task(sender->GetOutputStreamAsync(args->RemoteAddress, "1336")).then(
            [=](IOutputStream^ outputStream)
        {
            auto dataWriter = ref new DataWriter(outputStream);
            dataWriter->WriteString(request);
            Concurrency::create_task(dataWriter->StoreAsync()).then(
                [=](unsigned int)
            {
                dataWriter->DetachStream();

                this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler(
                    [=]()
                {
                    std::wstringstream wstringstream;
                    wstringstream << L"server sent back the response: \"" << request->Data() << L"\"";
                    this->serverListBox->Items->Append(ref new Platform::String(wstringstream.str().c_str()));

                    delete this->serverDatagramSocket;
                    this->serverDatagramSocket = nullptr;

                    this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler([=]() {this->serverListBox->Items->Append(L"server closed its socket"); }));
                }));
            });
        });
    }

    void StartClient()
    {
        try
        {
            // Create the DatagramSocket and establish a connection to the echo server.
            this->clientDatagramSocket = ref new Windows::Networking::Sockets::DatagramSocket();

            this->clientDatagramSocket->MessageReceived += ref new TypedEventHandler<Windows::Networking::Sockets::DatagramSocket^, Windows::Networking::Sockets::DatagramSocketMessageReceivedEventArgs^>(this, &DatagramSocketPage::ClientDatagramSocket_MessageReceived);

            // The server hostname that we will be establishing a connection to. In this example, the server and client are in the same process.
            auto hostName = ref new Windows::Networking::HostName(L"localhost");

            this->clientListBox->Items->Append(L"client is about to bind...");

            Concurrency::create_task(this->clientDatagramSocket->BindServiceNameAsync("1336")).then(
                [=]
            {
                this->clientListBox->Items->Append(L"client is bound to port number 1336");
            });

            // Send a request to the echo server.
            auto serverDatagramSocket = ref new Windows::Networking::Sockets::DatagramSocket();
            Concurrency::create_task(serverDatagramSocket->GetOutputStreamAsync(hostName, "1337")).then(
                [=](IOutputStream^ outputStream)
            {
                auto request = ref new Platform::String(L"Hello, World!");
                auto dataWriter = ref new DataWriter(outputStream);
                dataWriter->WriteString(request);
                Concurrency::create_task(dataWriter->StoreAsync()).then(
                    [=](unsigned int)
                {
                    dataWriter->DetachStream();
                    std::wstringstream wstringstream;
                    wstringstream << L"client sent the request: \"" << request->Data() << L"\"";
                    this->clientListBox->Items->Append(ref new Platform::String(wstringstream.str().c_str()));
                });

            });
        }
        catch (Platform::Exception^ ex)
        {
            Windows::Networking::Sockets::SocketErrorStatus webErrorStatus = Windows::Networking::Sockets::SocketError::GetStatus(ex->HResult);
            this->serverListBox->Items->Append(webErrorStatus.ToString() != L"Unknown" ? webErrorStatus.ToString() : ex->Message);
        }
    }

    void ClientDatagramSocket_MessageReceived(Windows::Networking::Sockets::DatagramSocket^ sender, Windows::Networking::Sockets::DatagramSocketMessageReceivedEventArgs^ args)
    {
        DataReader^ dataReader = args->GetDataReader();
        Platform::String^ response = dataReader->ReadString(dataReader->UnconsumedBufferLength);
        this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler(
            [=]
        {
            std::wstringstream wstringstream;
            wstringstream << L"client received the response: \"" << response->Data() << L"\"";
            this->clientListBox->Items->Append(ref new Platform::String(wstringstream.str().c_str()));
        }));

        delete this->clientDatagramSocket;
        this->clientDatagramSocket = nullptr;

        this->Dispatcher->RunAsync(CoreDispatcherPriority::Normal, ref new DispatchedHandler([=]() {this->clientListBox->Items->Append(L"client closed its socket"); }));
    }

Operace na pozadí a zprostředkovatel soketů

Pomocí zprostředkovatele soketů a triggerů řídicího kanálu můžete zajistit, aby vaše aplikace správně přijímala připojení nebo data prostřednictvím soketů, i když není v popředí. Další informace najdete v tématu Síťová komunikace na pozadí.

Dávkové odesílání

Při každém zápisu do datového proudu přidruženého k soketu dojde k přechodu z uživatelského režimu (vašeho kódu) do režimu jádra (kde je zásobník sítě). Pokud najednou zapisujete do mnoha bufferů, tyto opakované přechody se nasčítají a představují značnou režii. Dávkové odesílání je způsob, jak odeslat více datových bufferů najednou a vyhnout se tak této režii. Je zvlášť užitečné, pokud vaše aplikace provádí VoIP, VPN nebo jiné úlohy, které zahrnují co nejefektivnější přesun velkého množství dat.

Tato část ukazuje několik metod dávkového odesílání, které můžete použít se streamSocketem nebo připojeným datagramSocketem.

Abychom získali základní představu, podívejme se, jak neefektivně odeslat velké množství bufferů. Tady je minimální ukázka použití StreamSocketu.

protected override async void OnNavigatedTo(NavigationEventArgs e)
{
    var streamSocketListener = new Windows.Networking.Sockets.StreamSocketListener();
    streamSocketListener.ConnectionReceived += this.StreamSocketListener_ConnectionReceived;
    await streamSocketListener.BindServiceNameAsync("1337");

    var streamSocket = new Windows.Networking.Sockets.StreamSocket();
    await streamSocket.ConnectAsync(new Windows.Networking.HostName("localhost"), "1337");
    this.SendMultipleBuffersInefficiently(streamSocket, "Hello, World!");
    //this.BatchedSendsCSharpOnly(streamSocket, "Hello, World!");
    //this.BatchedSendsAnyUWPLanguage(streamSocket, "Hello, World!");
}

private async void StreamSocketListener_ConnectionReceived(Windows.Networking.Sockets.StreamSocketListener sender, Windows.Networking.Sockets.StreamSocketListenerConnectionReceivedEventArgs args)
{
    using (var dataReader = new DataReader(args.Socket.InputStream))
    {
        dataReader.InputStreamOptions = InputStreamOptions.Partial;
        while (true)
        {
            await dataReader.LoadAsync(256);
            if (dataReader.UnconsumedBufferLength == 0) break;
            IBuffer requestBuffer = dataReader.ReadBuffer(dataReader.UnconsumedBufferLength);
            string request = Windows.Security.Cryptography.CryptographicBuffer.ConvertBinaryToString(Windows.Security.Cryptography.BinaryStringEncoding.Utf8, requestBuffer);
            Debug.WriteLine(string.Format("server received the request: \"{0}\"", request));
        }
    }
}

// This implementation incurs kernel transition overhead for each packet written.
private async void SendMultipleBuffersInefficiently(Windows.Networking.Sockets.StreamSocket streamSocket, string message)
{
    var packetsToSend = new List<IBuffer>();
    for (int count = 0; count < 5; ++count) { packetsToSend.Add(Windows.Security.Cryptography.CryptographicBuffer.ConvertStringToBinary(message, Windows.Security.Cryptography.BinaryStringEncoding.Utf8)); }

    foreach (IBuffer packet in packetsToSend)
    {
        await streamSocket.OutputStream.WriteAsync(packet);
    }
}

#include <winrt/Windows.Foundation.h>
#include <winrt/Windows.Networking.Sockets.h>
#include <winrt/Windows.Security.Cryptography.h>
#include <winrt/Windows.Storage.Streams.h>
#include <winrt/Microsoft.UI.Dispatching.h>
#include <winrt/Microsoft.UI.Xaml.Navigation.h>
#include <sstream>

using namespace winrt;
using namespace Windows::Foundation;
using namespace Windows::Storage::Streams;
using namespace Microsoft::UI::Dispatching;
using namespace Microsoft::UI::Xaml::Navigation;
...
private:
    Windows::Networking::Sockets::StreamSocketListener m_streamSocketListener;
    Windows::Networking::Sockets::StreamSocket m_streamSocket;

public:
    IAsyncAction OnNavigatedTo(NavigationEventArgs /* e */)
    {
        m_streamSocketListener.ConnectionReceived({ this, &BatchedSendsPage::OnConnectionReceived });
        co_await m_streamSocketListener.BindServiceNameAsync(L"1337");

        co_await m_streamSocket.ConnectAsync(Windows::Networking::HostName{ L"localhost" }, L"1337");
        SendMultipleBuffersInefficientlyAsync(L"Hello, World!");
        //BatchedSendsAnyUWPLanguageAsync(L"Hello, World!");
    }

private:
    IAsyncAction OnConnectionReceived(Windows::Networking::Sockets::StreamSocketListener const& /* sender */, Windows::Networking::Sockets::StreamSocketListenerConnectionReceivedEventArgs const& args)
    {
        DataReader dataReader{ args.Socket().InputStream() };
        dataReader.InputStreamOptions(Windows::Storage::Streams::InputStreamOptions::Partial);

        while (true)
        {
            unsigned int bytesLoaded = co_await dataReader.LoadAsync(256);
            if (bytesLoaded == 0) break;
            winrt::hstring message{ dataReader.ReadString(bytesLoaded) };
            ::OutputDebugString(message.c_str());
        }
    }

    // This implementation incurs kernel transition overhead for each packet written.
    IAsyncAction SendMultipleBuffersInefficientlyAsync(winrt::hstring message)
    {
        co_await winrt::resume_background();

        std::vector< IBuffer > packetsToSend;
        for (unsigned int count = 0; count < 5; ++count)
        {
            packetsToSend.push_back(Windows::Security::Cryptography::CryptographicBuffer::ConvertStringToBinary(message, Windows::Security::Cryptography::BinaryStringEncoding::Utf8));
        }

        for (auto const& element : packetsToSend)
        {
            m_streamSocket.OutputStream().WriteAsync(element).get();
        }
    }

#include <ppltasks.h>
#include <sstream>
...
using namespace Windows::Foundation;
using namespace Windows::Storage::Streams;
using namespace Windows::UI::Core;
using namespace Windows::UI::Xaml::Navigation;
...
private:
    Windows::Networking::Sockets::StreamSocketListener^ streamSocketListener;
    Windows::Networking::Sockets::StreamSocket^ streamSocket;

protected:
    virtual void OnNavigatedTo(NavigationEventArgs^ e) override
    {
        this->streamSocketListener = ref new Windows::Networking::Sockets::StreamSocketListener();
        streamSocketListener->ConnectionReceived += ref new TypedEventHandler<Windows::Networking::Sockets::StreamSocketListener^, Windows::Networking::Sockets::StreamSocketListenerConnectionReceivedEventArgs^>(this, &BatchedSendsPage::StreamSocketListener_ConnectionReceived);
        Concurrency::create_task(this->streamSocketListener->BindServiceNameAsync(L"1337")).then(
            [=]
        {
            this->streamSocket = ref new Windows::Networking::Sockets::StreamSocket();
            Concurrency::create_task(this->streamSocket->ConnectAsync(ref new Windows::Networking::HostName(L"localhost"), L"1337")).then(
                [=](Concurrency::task< void >)
            {
                this->SendMultipleBuffersInefficiently(L"Hello, World!");
                // this->BatchedSendsAnyUWPLanguage(L"Hello, World!");
            }, Concurrency::task_continuation_context::use_synchronous_execution());
        });
    }

private:
    void StreamSocketListener_ConnectionReceived(Windows::Networking::Sockets::StreamSocketListener^ sender, Windows::Networking::Sockets::StreamSocketListenerConnectionReceivedEventArgs^ args)
    {
        auto dataReader = ref new DataReader(args->Socket->InputStream);
        dataReader->InputStreamOptions = Windows::Storage::Streams::InputStreamOptions::Partial;
        this->ReceiveStringRecurse(dataReader, args->Socket);
    }

    void ReceiveStringRecurse(DataReader^ dataReader, Windows::Networking::Sockets::StreamSocket^ streamSocket)
    {
        Concurrency::create_task(dataReader->LoadAsync(256)).then(
            [this, dataReader, streamSocket](unsigned int bytesLoaded)
        {
            if (bytesLoaded == 0) return;
            Platform::String^ message = dataReader->ReadString(bytesLoaded);
            ::OutputDebugString(message->Data());
            this->ReceiveStringRecurse(dataReader, streamSocket);
        });
    }

    // This implementation incurs kernel transition overhead for each packet written.
    void SendMultipleBuffersInefficiently(Platform::String^ message)
    {
        std::vector< IBuffer^ > packetsToSend{};
        for (unsigned int count = 0; count < 5; ++count)
        {
            packetsToSend.push_back(Windows::Security::Cryptography::CryptographicBuffer::ConvertStringToBinary(message, Windows::Security::Cryptography::BinaryStringEncoding::Utf8));
        }

        for (auto element : packetsToSend)
        {
            Concurrency::create_task(this->streamSocket->OutputStream->WriteAsync(element)).wait();
        }
    }

Tento první příklad efektivnější techniky je vhodný pouze v případě, že používáte jazyk C#. Změňte OnNavigatedTo tak, aby volalo BatchedSendsCSharpOnly místo SendMultipleBuffersInefficiently nebo SendMultipleBuffersInefficientlyAsync.

// A C#-only technique for batched sends.
private async void BatchedSendsCSharpOnly(Windows.Networking.Sockets.StreamSocket streamSocket, string message)
{
    var packetsToSend = new List<IBuffer>();
    for (int count = 0; count < 5; ++count) { packetsToSend.Add(Windows.Security.Cryptography.CryptographicBuffer.ConvertStringToBinary(message, Windows.Security.Cryptography.BinaryStringEncoding.Utf8)); }

    var pendingTasks = new System.Threading.Tasks.Task[packetsToSend.Count];

    for (int index = 0; index < packetsToSend.Count; ++index)
    {
        // track all pending writes as tasks, but don't wait on one before beginning the next.
        pendingTasks[index] = streamSocket.OutputStream.WriteAsync(packetsToSend[index]).AsTask();
        // Don't modify any buffer's contents until the pending writes are complete.
    }

    // Wait for all of the pending writes to complete.
    System.Threading.Tasks.Task.WaitAll(pendingTasks);
}

Tento další příklad je vhodný pro jakýkoli jazyk UPW, nejen pro jazyk C#. Spoléhá na chování streamSocket.OutputStream a DatagramSocket.OutputStream , které dávky odesílají dohromady. Technika volá FlushAsync u tohoto výstupního streamu, který od Windows 10 zaručuje, že se vrátí až po dokončení všech operací s výstupním streamem.

// An implementation of batched sends suitable for any UWP language.
private async void BatchedSendsAnyUWPLanguage(Windows.Networking.Sockets.StreamSocket streamSocket, string message)
{
    var packetsToSend = new List<IBuffer>();
    for (int count = 0; count < 5; ++count) { packetsToSend.Add(Windows.Security.Cryptography.CryptographicBuffer.ConvertStringToBinary(message, Windows.Security.Cryptography.BinaryStringEncoding.Utf8)); }

    var pendingWrites = new IAsyncOperationWithProgress<uint, uint>[packetsToSend.Count];

    for (int index = 0; index < packetsToSend.Count; ++index)
    {
        // track all pending writes as tasks, but don't wait on one before beginning the next.
        pendingWrites[index] = streamSocket.OutputStream.WriteAsync(packetsToSend[index]);
        // Don't modify any buffer's contents until the pending writes are complete.
    }

    // Wait for all of the pending writes to complete. This step enables batched sends on the output stream.
    await streamSocket.OutputStream.FlushAsync();
}

// An implementation of batched sends suitable for any UWP language.
IAsyncAction BatchedSendsAnyUWPLanguageAsync(winrt::hstring message)
{
    std::vector< IBuffer > packetsToSend{};
    std::vector< IAsyncOperationWithProgress< unsigned int, unsigned int > > pendingWrites{};
    for (unsigned int count = 0; count < 5; ++count)
    {
        packetsToSend.push_back(Windows::Security::Cryptography::CryptographicBuffer::ConvertStringToBinary(message, Windows::Security::Cryptography::BinaryStringEncoding::Utf8));
    }

    for (auto const& element : packetsToSend)
    {
        // track all pending writes as tasks, but don't wait on one before beginning the next.
        pendingWrites.push_back(m_streamSocket.OutputStream().WriteAsync(element));
        // Don't modify any buffer's contents until the pending writes are complete.
    }

    // Wait for all of the pending writes to complete. This step enables batched sends on the output stream.
    co_await m_streamSocket.OutputStream().FlushAsync();
}

private:
    // An implementation of batched sends suitable for any UWP language.
    void BatchedSendsAnyUWPLanguage(Platform::String^ message)
    {
        std::vector< IBuffer^ > packetsToSend{};
        std::vector< IAsyncOperationWithProgress< unsigned int, unsigned int >^ >pendingWrites{};
        for (unsigned int count = 0; count < 5; ++count)
        {
            packetsToSend.push_back(Windows::Security::Cryptography::CryptographicBuffer::ConvertStringToBinary(message, Windows::Security::Cryptography::BinaryStringEncoding::Utf8));
        }

        for (auto element : packetsToSend)
        {
            // track all pending writes as tasks, but don't wait on one before beginning the next.
            pendingWrites.push_back(this->streamSocket->OutputStream->WriteAsync(element));
            // Don't modify any buffer's contents until the pending writes are complete.
        }

        // Wait for all of the pending writes to complete. This step enables batched sends on the output stream.
        Concurrency::create_task(this->streamSocket->OutputStream->FlushAsync());
    }

Použití dávkových odesílání v kódu má několik důležitých omezení.

Obsah instancí IBuffer , které se zapisují, nelze upravit, dokud nebude dokončen asynchronní zápis.
Model FlushAsync funguje pouze u StreamSocket.OutputStream a DatagramSocket.OutputStream.
Vzor FlushAsync funguje jenom v Windows 10 a dále.
V jiných případech místo vzoru FlushAsync použijte Task.WaitAll.

DatagramSocket můžete nakonfigurovat tak, aby spoluexistovali s jinými sokety vícesměrového vysílání Win32 nebo UPW vázané na stejnou adresu nebo port. Provedete to nastavením DatagramSocketControl.MulticastOnly na true před svázáním nebo připojením soketu. Přistupujete k instanci DatagramSocketControl ze samotného objektu DatagramSocket prostřednictvím jeho DatagramSocket.Control vlastnost.

Poskytnutí klientského certifikátu s třídou StreamSocket

StreamSocket podporuje ověřování serveru, se kterým klientská aplikace mluví, pomocí protokolu SSL/TLS. V některých případech se klientská aplikace musí ověřit na serveru pomocí klientského certifikátu SSL/TLS. Klientský certifikát můžete zadat pomocí vlastnosti StreamSocketControl.ClientCertificate před svázáním nebo připojením soketu (musí být nastavena před zahájením handshake SSL/TLS). Přistupujete k instanci StreamSocketControl z samotného objektu StreamSocket prostřednictvím jeho StreamSocket.Control vlastnost. Pokud server požádá o klientský certifikát, Windows odpoví klientským certifikátem, který jste zadali.

Použijte přetížení StreamSocket.ConnectAsync, které přijímá parametr SocketProtectionLevel, jak je znázorněno v této minimální ukázce kódu.

Important

Jak je uvedeno v komentáři v níže uvedených příkladech kódu, váš projekt musí deklarovat funkci aplikace sharedUserCertificates, aby tento kód fungoval.

// For this code to work, you need at least one certificate to be present in the user MY certificate store.
// Plugging a smartcard into a smartcard reader connected to your PC will achieve that.
// Also, your project needs to declare the sharedUserCertificates app capability.
var certificateQuery = new Windows.Security.Cryptography.Certificates.CertificateQuery();
certificateQuery.StoreName = "MY";
IReadOnlyList<Windows.Security.Cryptography.Certificates.Certificate> certificates = await Windows.Security.Cryptography.Certificates.CertificateStores.FindAllAsync(certificateQuery);
if (certificates.Count > 0)
{
    streamSocket.Control.ClientCertificate = certificates[0];
    await streamSocket.ConnectAsync(hostName, "1337", Windows.Networking.Sockets.SocketProtectionLevel.Tls12);
}

// For this code to work, you need at least one certificate to be present in the user MY certificate store.
// Plugging a smartcard into a smartcard reader connected to your PC will achieve that.
// Also, your project needs to declare the sharedUserCertificates app capability.
Windows::Security::Cryptography::Certificates::CertificateQuery certificateQuery;
certificateQuery.StoreName(L"MY");
IVectorView< Windows::Security::Cryptography::Certificates::Certificate > certificates = co_await Windows::Security::Cryptography::Certificates::CertificateStores::FindAllAsync(certificateQuery);

if (certificates.Size() > 0)
{
    m_streamSocket.Control().ClientCertificate(certificates.GetAt(0));
    co_await m_streamSocket.ConnectAsync(Windows::Networking::HostName{ L"localhost" }, L"1337", Windows::Networking::Sockets::SocketProtectionLevel::Tls12);
    ...
}

// For this code to work, you need at least one certificate to be present in the user MY certificate store.
// Plugging a smartcard into a smartcard reader connected to your PC will achieve that.
// Also, your project needs to declare the sharedUserCertificates app capability.
auto certificateQuery = ref new Windows::Security::Cryptography::Certificates::CertificateQuery();
certificateQuery->StoreName = L"MY";
Concurrency::create_task(Windows::Security::Cryptography::Certificates::CertificateStores::FindAllAsync(certificateQuery)).then(
    [=](IVectorView< Windows::Security::Cryptography::Certificates::Certificate^ >^ certificates)
{
    if (certificates->Size > 0)
    {
        this->streamSocket->Control->ClientCertificate = certificates->GetAt(0);
        Concurrency::create_task(this->streamSocket->ConnectAsync(ref new Windows::Networking::HostName(L"localhost"), L"1337", Windows::Networking::Sockets::SocketProtectionLevel::Tls12)).then(
            [=]
        {
            ...
        });
    }
});

Zpracování výjimek

Jako hodnota HRESULT se vrátí chyba při operaci DatagramSocket, StreamSocket nebo StreamSocketListener. Tuto hodnotu HRESULT můžete předat metodě SocketError.GetStatus a převést ji na hodnotu výčtu SocketErrorStatus .

Většina hodnot výčtu SocketErrorStatus odpovídá chybě vrácené nativní operací soketů Windows. Aplikace může podle hodnot výčtu SocketErrorStatus upravit své chování v závislosti na příčině výjimky.

V případě chyb při ověřování parametrů můžete použít hodnotu HRESULT z výjimky a zjistit tak podrobnější informace o chybě. Možné hodnoty HRESULT jsou uvedeny v Winerror.hseznamu , které lze najít v instalaci sady SDK (například ve složce C:\Program Files (x86)\Windows Kits\10\Include\<VERSION>\shared). U většiny chyb ověřování parametrů je vrácena hodnota HRESULTE_INVALIDARG.

Konstruktor HostName může vyvolat výjimku, pokud předaný řetězec není platným názvem hostitele. Obsahuje například nepovolené znaky, což je pravděpodobné, že pokud uživatel zadá název hostitele do vaší aplikace. Vytvořte HostName v bloku try/catch. Pokud dojde k vyvolání výjimky, aplikace může uživatele upozornit a požádat o nový název hostitele.

Důležitá rozhraní API

Samples

Ukázka streamSocketu

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Last updated on 2026-07-01