项目
11/17/2011

WebException Constructor (String, Exception)

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Initializes a new instance of the WebException class with the specified error message and nested exception.

Namespace: System.Net
Assembly: System.Net (in System.Net.dll)

Syntax

'Declaration
Public Sub New ( _
    message As String, _
    innerException As Exception _
)

public WebException(
    string message,
    Exception innerException
)

Parameters

message
Type: System.String
The text of the error message.

innerException
Type: System.Exception
A nested exception.

Remarks

The WebException instance is initialized with the Message property set to the value of message and the InnerException property set to the value of innerException. If message is nulla null reference (Nothing in Visual Basic), the Message property is initialized to a system-supplied message. The InnerException and Response properties are initialized to nulla null reference (Nothing in Visual Basic). The Status property is initialized to RequestCanceled.

Examples

The following example throws a WebException by specifying an error message and nested exception.

  public class Example
  {
    static ManualResetEvent clientDone = new ManualResetEvent(false);

    public static void Demo(System.Windows.Controls.TextBlock outputBlock)
    {
        SocketAsyncEventArgs socketEventArg = new SocketAsyncEventArgs();
            DnsEndPoint hostEntry = new DnsEndPoint("https://www.contoso.com", 80);

        // Create a socket and connect to the server
        Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

        socketEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(SocketEventArg_Completed);

        socketEventArg.RemoteEndPoint = hostEntry;
        socketEventArg.UserToken = sock;
        sock.ConnectAsync(socketEventArg);
        clientDone.WaitOne();
    }

    static void SocketEventArg_Completed(object sender, SocketAsyncEventArgs e)
    {
         if (e.LastOperation == SocketAsyncOperation.Connect) {
           if (e.SocketError == SocketError.Success)
            {
                // Successfully connected to the server

            }
            else
            {
                  // Throw the WebException with a string
                    throw new WebException("Unable to connect to 'www.contoso.com' Uri.",new SocketException());
                }
             } 
             // socket operation not a connect!  
         else
            throw new Exception("Invalid operation completed");
    }
  }

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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