WebRequest.EndGetRequestStream-Methode

Artikel
08/20/2007

Gibt beim Überschreiben in einer abgeleiteten Klasse einen Stream zum Schreiben von Daten in die Internetressource zurück.

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

Syntax

'Declaration
Public Overridable Function EndGetRequestStream ( _
    asyncResult As IAsyncResult _
) As Stream
'Usage
Dim instance As WebRequest
Dim asyncResult As IAsyncResult
Dim returnValue As Stream

returnValue = instance.EndGetRequestStream(asyncResult)

public virtual Stream EndGetRequestStream (
    IAsyncResult asyncResult
)

public:
virtual Stream^ EndGetRequestStream (
    IAsyncResult^ asyncResult
)

public Stream EndGetRequestStream (
    IAsyncResult asyncResult
)

public function EndGetRequestStream (
    asyncResult : IAsyncResult
) : Stream

Parameter

asyncResult
Ein IAsyncResult, das auf eine ausstehende Anforderung eines Streams verweist.

Rückgabewert

Ein Stream, in den Daten geschrieben werden können.

Ausnahmen

Ausnahmetyp	Bedingung
NotImplementedException	Es wurde versucht, auf die Methode zuzugreifen, obwohl die Methode in einer abgeleiteten Klasse nicht überschrieben wurde.

Hinweise

Die EndGetRequestStream-Methode schließt eine asynchrone Streamanforderung ab, die mit der BeginGetRequestStream-Methode gestartet wurde.

Hinweis

Schließen Sie den Antwortstream unbedingt, indem Sie die Close-Methode für den von GetResponseStream zurückgegebenen Stream nach dem Aufruf von EndGetResponse aufrufen. So können Probleme mit den Zeitabläufen der Garbarge Collection vermieden werden.

Hinweis

Die WebRequest-Klasse ist eine abstract Klasse. Das tatsächliche Verhalten von WebRequest-Instanzen zur Laufzeit wird von der abgeleiteten Klasse bestimmt, die von der System.Net.WebRequest.Create-Methode zurückgegeben wird. Weitere Informationen über Standardwerte und Ausnahmen finden Sie in der Dokumentation zu den abgeleiteten Klassen, z. B. HttpWebRequest und FileWebRequest.

Beispiel

Im folgenden Beispiel wird ein Anforderungsstream durch einen Aufruf von EndGetRequestStream abgerufen und verwendet. Die EndGetRequestStream-Methode schließt den asynchronen Aufruf von BeginGetRequestStream ab.

Imports System
Imports System.Net
Imports System.IO
Imports System.Text
Imports System.Threading
Imports Microsoft.VisualBasic

Public Class RequestState
    ' This class stores the request state of the request.
    Public request As WebRequest
    
    Public Sub New()
        request = Nothing
    End Sub ' New
End Class ' RequestState


Class WebRequest_BeginGetRequeststream
    Public Shared allDone As New ManualResetEvent(False)
    
    Shared Sub Main()
          ' Create a new request.
            Dim myWebRequest As WebRequest = WebRequest.Create("https://www.contoso.com/codesnippets/next.asp")
 ' Create an instance of the RequestState and assign 
            ' myWebRequest' to it's request field.
            Dim myRequestState As New RequestState()
            myRequestState.request = myWebRequest
            myWebRequest.ContentType = "application/x-www-form-urlencoded"

            ' Set the 'Method' property  to 'POST' to post data to a Uri.
            myRequestState.request.Method = "POST"
            ' Start the asynchronous 'BeginGetRequestStream' method call.
            Dim r As IAsyncResult = CType(myWebRequest.BeginGetRequestStream(AddressOf ReadCallback, myRequestState), IAsyncResult)
            ' Pause the current thread until the async operation completes.
            allDone.WaitOne()
            ' Send the Post and get the response.
            Dim myWebResponse As WebResponse = myWebRequest.GetResponse()
            Console.WriteLine(ControlChars.Cr + "The string has been posted.")
            Console.WriteLine("Please wait for the response....")
            Dim streamResponse As Stream = myWebResponse.GetResponseStream()
            Dim streamRead As New StreamReader(streamResponse)
            Dim readBuff(256) As [Char]
            Dim count As Integer = streamRead.Read(readBuff, 0, 256)
            Console.WriteLine(ControlChars.Cr + "The contents of the HTML page are ")
            While count > 0
                Dim outputData As New [String](readBuff, 0, count)
                Console.WriteLine(outputData)
                count = streamRead.Read(readBuff, 0, 256)
            End While

           ' Close the Stream Object.
            streamResponse.Close()
            streamRead.Close()
            ' Release the HttpWebResponse Resource.
             myWebResponse.Close()
    End Sub ' Main
     
    Private Shared Sub ReadCallback(asynchronousResult As IAsyncResult)
            Dim myRequestState As RequestState = CType(asynchronousResult.AsyncState, RequestState)
            Dim myWebRequest As WebRequest = myRequestState.request
            ' End the request.
            Dim streamResponse As Stream = myWebRequest.EndGetRequestStream(asynchronousResult)
            ' Create a string that is to be posted to the uri.
            Console.WriteLine(ControlChars.Cr + "Please enter a string to be posted:")
            Dim postData As String = Console.ReadLine()
            Dim encoder As New ASCIIEncoding()
            ' Convert  the string into a byte array.
            Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
            ' Write the data to the stream.
            streamResponse.Write(byteArray, 0, postData.Length)
            streamResponse.Close()
            ' Allow the main thread to resume.
            allDone.Set()
    End Sub ' ReadCallback 
End Class ' WebRequest_BeginGetRequeststream

using System;
using System.Net;
using System.IO;
using System.Text;
using System.Threading;

public class RequestState
{
    // This class stores the request state of the request.
    public WebRequest request;    
    public RequestState()
    {
        request = null;
    }
}

class WebRequest_BeginGetRequeststream
{
    public static ManualResetEvent allDone= new ManualResetEvent(false);
    static void Main()
    {
            // Create a new request to the mentioned URL.    
            WebRequest myWebRequest= WebRequest.Create("https://www.contoso.com");

            // Create an instance of the RequestState and assign 
            // 'myWebRequest' to it's request field.    
            RequestState myRequestState = new RequestState();
            myRequestState.request = myWebRequest;            
            myWebRequest.ContentType="application/x-www-form-urlencoded";

            // Set the 'Method' property  to 'POST' to post data to a Uri.
            myRequestState.request.Method="POST";
            // Start the Asynchronous 'BeginGetRequestStream' method call.    
            IAsyncResult r=(IAsyncResult) myWebRequest.BeginGetRequestStream(
                new AsyncCallback(ReadCallback),myRequestState);
            // Pause the current thread until the async operation completes.
            Console.WriteLine("main thread waiting...");
            allDone.WaitOne();   
            // Assign the response object of 'WebRequest' to a 'WebResponse' variable.
            WebResponse myWebResponse = myWebRequest.GetResponse();
            Console.WriteLine("The string has been posted.");    
            Console.WriteLine("Please wait for the response...");

            Stream streamResponse = myWebResponse.GetResponseStream();
            StreamReader streamRead = new StreamReader( streamResponse );
            Char[] readBuff = new Char[256];
            int count = streamRead.Read( readBuff, 0, 256 );
            Console.WriteLine("\nThe contents of the HTML page are ");    

            while (count > 0) 
            {
                String outputData = new String(readBuff, 0, count);
                Console.Write(outputData);
                count = streamRead.Read(readBuff, 0, 256);
            }

            // Close the Stream Object.
            streamResponse.Close();
            streamRead.Close();
 

            // Release the HttpWebResponse Resource.
            myWebResponse.Close();            
    }
    private static void ReadCallback(IAsyncResult asynchronousResult)
    {
            RequestState myRequestState =(RequestState) asynchronousResult.AsyncState;
            WebRequest  myWebRequest = myRequestState.request;

            // End the Asynchronus request.
            Stream streamResponse = myWebRequest.EndGetRequestStream(asynchronousResult);

            // Create a string that is to be posted to the uri.
            Console.WriteLine("Please enter a string to be posted:");
            string postData = Console.ReadLine();
            // Convert the string into a byte array.
            byte[] byteArray = Encoding.UTF8.GetBytes(postData);

            // Write the data to the stream.
            streamResponse.Write(byteArray,0,postData.Length);
            streamResponse.Close();
            allDone.Set();
    }
}

#using <System.dll>

using namespace System;
using namespace System::Net;
using namespace System::IO;
using namespace System::Text;
using namespace System::Threading;
public ref class RequestState
{
public:

   // This class stores the request state of the request.
   WebRequest^ request;
   RequestState()
   {
      request = nullptr;
   }

};

ref class WebRequest_BeginGetRequeststream
{
public:
   static ManualResetEvent^ allDone = gcnew ManualResetEvent( false );
   static void ReadCallback( IAsyncResult^ asynchronousResult )
   {
      RequestState^ myRequestState = dynamic_cast<RequestState^>(asynchronousResult->AsyncState);
      WebRequest^ myWebRequest = myRequestState->request;
      
      // End of the Asynchronus request.
      Stream^ streamResponse = myWebRequest->EndGetRequestStream( asynchronousResult );
      
      // Create a string that is to be posted to the uri.
      Console::WriteLine( "Please enter a string to be posted:" );
      String^ postData = Console::ReadLine();
      
      // Convert  the string into a Byte array.
      array<Byte>^byteArray = Encoding::UTF8->GetBytes( postData );
      
      // Write data to the stream.
      streamResponse->Write( byteArray, 0, postData->Length );
      streamResponse->Close();
      allDone->Set();
   }

};

int main()
{
   
   // Create a new request to the mentioned URL.
   WebRequest^ myWebRequest = WebRequest::Create( "https://www.contoso.com" );
   
   // Create an instance of the RequestState and assign 'myWebRequest' to its request field.
   RequestState^ myRequestState = gcnew RequestState;
   myRequestState->request = myWebRequest;
   myWebRequest->ContentType = "application/x-www-form-urlencoded";
   
   // Set the 'Method' prperty  to 'POST' to post data to a Uri.
   myRequestState->request->Method = "POST";
   
   // Start the Asynchronous 'BeginGetRequestStream' method call.
   IAsyncResult^ r = dynamic_cast<IAsyncResult^>(myWebRequest->BeginGetRequestStream( gcnew AsyncCallback( WebRequest_BeginGetRequeststream::ReadCallback ), myRequestState ));
   WebRequest_BeginGetRequeststream::allDone->WaitOne();
   WebResponse^ myWebResponse = myWebRequest->GetResponse();
   Console::WriteLine( "The String* entered has been posted." );
   Console::WriteLine( "Please wait for the response..." );
   Stream^ streamResponse = myWebResponse->GetResponseStream();
   StreamReader^ streamRead = gcnew StreamReader( streamResponse );
   array<Char>^readBuff = gcnew array<Char>(256);
   int count = streamRead->Read( readBuff, 0, 256 );
   Console::WriteLine( "The contents of the HTML page are " );
   while ( count > 0 )
   {
      String^ outputData = gcnew String( readBuff,0,count );
      Console::Write( outputData );
      count = streamRead->Read( readBuff, 0, 256 );
   }

   streamResponse->Close();
   streamRead->Close();
   
   // Release the HttpWebResponse Resource.
   myWebResponse->Close();
}

import System.*;
import System.Net.*;
import System.IO.*;
import System.Text.*;
import System.Threading.*;
public class RequestState
{
    // This class stores the request state of the request.
    public WebRequest request;

    public RequestState()
    {
        request = null;
    } //RequestState
} //RequestState

class WebRequest_BeginGetRequeststream
{
    public static ManualResetEvent allDone = new ManualResetEvent(false);

    public static void main(String[] args)
    {
        // Create a new request to the mentioned URL.    
        WebRequest myWebRequest = WebRequest.Create("https://www.contoso.com");
        // Create an instance of the RequestState and assign 
        // 'myWebRequest' to it's request field.    
        RequestState myRequestState = new RequestState();
        myRequestState.request = myWebRequest;
        myWebRequest.set_ContentType("application/x-www-form-urlencoded");
        // Set the 'Method' property  to 'POST' to post data to a Uri.
        myRequestState.request.set_Method("POST");

        // Start the Asynchronous 'BeginGetRequestStream' method call.    
        IAsyncResult r = (IAsyncResult)(myWebRequest.BeginGetRequestStream(
            new AsyncCallback(ReadCallback), myRequestState));
        // Pause the current thread until the async operation completes.
        Console.WriteLine("main thread waiting...");
        allDone.WaitOne();
        // Assign the response object of 'WebRequest' to a 'WebResponse' 
        // variable.
        WebResponse myWebResponse = myWebRequest.GetResponse();
        Console.WriteLine("The string has been posted.");
        Console.WriteLine("Please wait for the response...");

        Stream streamResponse = myWebResponse.GetResponseStream();
        StreamReader streamRead = new StreamReader(streamResponse);
        char readBuff[] = new char[256];
        int count = streamRead.Read(readBuff, 0, 256);
        Console.WriteLine("\nThe contents of the HTML page are ");

        while (count > 0) {
            String outputData = new String(readBuff, 0, count);
            Console.Write(outputData);
            count = streamRead.Read(readBuff, 0, 256);
        }
        // Close the Stream Object.
        streamResponse.Close();
        streamRead.Close();
        // Release the HttpWebResponse Resource.
        myWebResponse.Close();
    } //main

    private static void ReadCallback(IAsyncResult asynchronousResult)
    {
        RequestState myRequestState = 
            (RequestState) asynchronousResult.get_AsyncState();
        WebRequest myWebRequest = myRequestState.request;
        // End the Asynchronus request.
        Stream streamResponse = myWebRequest.EndGetRequestStream(
            asynchronousResult);
        // Create a string that is to be posted to the uri.
        Console.WriteLine("Please enter a string to be posted:");
        String postData = Console.ReadLine();
        // Convert the string into a byte array.
        ubyte byteArray[] = Encoding.get_UTF8().GetBytes(postData);
        // Write the data to the stream.
        streamResponse.Write(byteArray, 0, postData.get_Length());
        streamResponse.Close();
        allDone.Set();
    } //ReadCallback
} //WebRequest_BeginGetRequeststream

Plattformen

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Freigeben über

WebRequest.EndGetRequestStream-Methode

Syntax

Parameter

Rückgabewert

Ausnahmen

Hinweise

Beispiel

Plattformen

Versionsinformationen

.NET Framework

.NET Compact Framework

Siehe auch

Referenz

Weitere Ressourcen

Zusätzliche Ressourcen