Erfassen von Ausnahmen

You place the sections of code that might throw exceptions in a try block and place code that handles exceptions in a catch block. The order of catch statements is important. Wenn eine Ausnahme auftritt, wird sie im Stapel übergeben, und jeder Catch-Block erhält die Möglichkeit, sie zu behandeln. The catch block that should handle the exception is determined by matching the type of the exception to the name of the exception specified in the catch block. For example, the following catch block catches Simple Object Access Protocol (SOAP) exceptions:

catch (SoapException e)
{
  Console.WriteLine("SOAP Exception Error Code: {0}", e.SubCode.Code.Name);
  Console.WriteLine("SOAP Exception Message is: {0}", e.Message);
}

Catch e As SoapException
  Console.WriteLine("SOAP Exception Error Code: {0}", e.SubCode.Code.Name)
  Console.WriteLine("SOAP Exception Message is: {0}", e.Message)
End Try

Wenn kein typspezifischer Catch-Block vorhanden ist, wird die Ausnahme von einem allgemeinen Catch-Block abgefangen, sofern vorhanden. For example, you can catch general exceptions by adding the following code:

catch (Exception e)
{
  Console.WriteLine("Exception Message: {0}", e.Message);
}

Catch e As Exception
  Console.WriteLine("Exception Message: {0}", e.Message)
End Try

You place catch blocks targeted to specific types of exceptions before a general exception. Die Common Language Runtime fängt Ausnahmen ab, die nicht von einem Catch-Block abgefangen werden. Depending on how the runtime is configured, either a debug dialog box appears, or the program stops executing and a dialog box with exception information appears.

Beispiel

using System;
using System.Text;
using System.Web.Services.Protocols;
using ExcelWebService.myserver02;
namespace ExcelWebService
{
  class WebService
  {
    [STAThread]
    static void Main(string[] args)
    {
      // Instantiate the Web service and make a status array object
      ExcelService xlservice = new ExcelService();
      Status[] outStatus;
      RangeCoordinates rangeCoordinates = new RangeCoordinates();
      string sheetName = "Sheet1";

      // Set the path to the workbook to open.
      // TODO: Change the path to the workbook
      // to point to a workbook you have access to.
      // The workbook must be in a trusted location.
      // If workbookPath is a UNC path, the application
      // must be on the same computer as the server.
      // string targetWorkbookPath =
      // @"\\\\MyServer\\myxlfiles\\Formulas.xlsx";
      string targetWorkbookPath =
      "http://myserver02/DocLib/Shared%20Documents/Basic1.xlsx";
      // Set credentials for requests
      xlservice.Credentials =
         System.Net.CredentialCache.DefaultCredentials;

      try
      {
        // Call the OpenWorkbook method and point to the
        // trusted location of the workbook to open.
        string sessionId = xlservice.OpenWorkbook(targetWorkbookPath, "en-US", "en-US", out outStatus);
        Console.WriteLine("sessionID : {0}", sessionId);
        // Prepare object to define range coordinates,
        // and call the GetRange method.
        rangeCoordinates.Column = 0;
        rangeCoordinates.Row = 0;
        rangeCoordinates.Height = 18;
        rangeCoordinates.Width = 10;

        object[] rangeResult1 = xlservice.GetRange(sessionId, sheetName, rangeCoordinates, false, out outStatus);
        Console.WriteLine("Total rows in range: " + rangeResult1.Length);

        Console.WriteLine("Sum in last column is: " + ((object[])rangeResult1[2])[3]);

        // Close the workbook. This also closes the session.
        xlservice.CloseWorkbook(sessionId);
      }
      catch (SoapException e)
      {
        Console.WriteLine("SOAP Exception Error Code: {0}", e.SubCode.Code.Name);
        Console.WriteLine("SOAP Exception Message is: {0}", e.Message);
      }

      catch (Exception e)
      {
        Console.WriteLine("Exception Message: {0}", e.Message);
      }
      Console.ReadLine();
    }
  }
}

Imports System
Imports System.Text
Imports System.Web.Services.Protocols
Imports ExcelWebService.myserver02
Namespace ExcelWebService
  Friend Class WebService
    <STAThread> _
    Shared Sub Main(ByVal args() As String)
      ' Instantiate the Web service and make a status array object
      Dim xlservice As New ExcelService()
      Dim outStatus() As Status
      Dim rangeCoordinates As New RangeCoordinates()
      Dim sheetName As String = "Sheet1"

      ' Set the path to the workbook to open.
      ' TODO: Change the path to the workbook
      ' to point to a workbook you have access to.
      ' The workbook must be in a trusted location.
      ' If workbookPath is a UNC path, the application
      ' must be on the same computer as the server.
      ' string targetWorkbookPath =
      ' @"\\\\MyServer\\myxlfiles\\Formulas.xlsx";
      Dim targetWorkbookPath As String = "http://myserver02/DocLib/Shared%20Documents/Basic1.xlsx"
      ' Set credentials for requests
      xlservice.Credentials = System.Net.CredentialCache.DefaultCredentials

      Try
        ' Call the OpenWorkbook method and point to the
        ' trusted location of the workbook to open.
        Dim sessionId As String = xlservice.OpenWorkbook(targetWorkbookPath, "en-US", "en-US", outStatus)
        Console.WriteLine("sessionID : {0}", sessionId)
        ' Prepare object to define range coordinates,
        ' and call the GetRange method.
        rangeCoordinates.Column = 0
        rangeCoordinates.Row = 0
        rangeCoordinates.Height = 18
        rangeCoordinates.Width = 10

        Dim rangeResult1() As Object = xlservice.GetRange(sessionId, sheetName, rangeCoordinates, False, outStatus)
        Console.WriteLine("Total rows in range: " &amp; rangeResult1.Length)

        Console.WriteLine("Sum in last column is: " &amp; (CType(rangeResult1(2), Object()))(3))

       ' Close the workbook. This also closes the session.
        xlservice.CloseWorkbook(sessionId)
      Catch e As SoapException
        Console.WriteLine("SOAP Exception Error Code: {0}", e.SubCode.Code.Name)
        Console.WriteLine("SOAP Exception Message is: {0}", e.Message)

      Catch e As Exception
        Console.WriteLine("Exception Message: {0}", e.Message)
      End Try
      Console.ReadLine()
    End Sub
  End Class
End Namespace

Siehe auch

Aufgaben

Konzepte

Sonstige Ressourcen

  • Last updated on