Ends an asynchronous request to an Internet resource.
Namespace:
System.Net
Assembly:
System (in System.dll)
Visual Basic (Declaration)
Public Overrides Function EndGetResponse ( _
asyncResult As IAsyncResult _
) As WebResponse
Dim instance As HttpWebRequest
Dim asyncResult As IAsyncResult
Dim returnValue As WebResponse
returnValue = instance.EndGetResponse(asyncResult)
public override WebResponse EndGetResponse(
IAsyncResult asyncResult
)
public:
virtual WebResponse^ EndGetResponse(
IAsyncResult^ asyncResult
) override
public override function EndGetResponse(
asyncResult : IAsyncResult
) : WebResponse
The EndGetResponse method completes an asynchronous request for an Internet resource that was started by calling the BeginGetResponse method.
Caution: |
|---|
You must call the Close method to close the stream and release the connection. Failure to do so may cause your application to run out of connections. |
Note: |
|---|
This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing. |
The following code example uses the EndGetResponse method to end an asynchronous request for an Internet resource.
Try
' Create a new HttpWebrequest object to the desired URL.
Dim myHttpWebRequest1 As HttpWebRequest = CType(WebRequest.Create("http://www.contoso.com"), HttpWebRequest)
' Create an instance of the RequestState and assign the previous myHttpWebRequest1
' object to it's request field.
Dim myRequestState As New RequestState()
myRequestState.request = myHttpWebRequest1
' Start the Asynchronous request.
Dim result As IAsyncResult = CType(myHttpWebRequest1.BeginGetResponse(AddressOf RespCallback, myRequestState), IAsyncResult)
allDone.WaitOne()
' Release the HttpWebResponse resource.
myRequestState.response.Close()
Catch e As WebException
Console.WriteLine(ControlChars.Cr + "Exception raised!")
Console.WriteLine(ControlChars.Cr + "Message:{0}", e.Message)
Console.WriteLine(ControlChars.Cr + "Status:{0}", e.Status)
Console.WriteLine("Press any key to continue..........")
Catch e As Exception
Console.WriteLine(ControlChars.Cr + "Exception raised!")
Console.WriteLine("Source :{0} ", e.Source)
Console.WriteLine("Message : {0}", e.Message)
Console.WriteLine("Press any key to continue..........")
Console.Read()
End Try
End Sub ' Main
Private Shared Sub RespCallback(asynchronousResult As IAsyncResult)
Try
' State of request is asynchronous.
Dim myRequestState As RequestState = CType(asynchronousResult.AsyncState, RequestState)
Dim myHttpWebRequest2 As HttpWebRequest = myRequestState.request
myRequestState.response = CType(myHttpWebRequest2.EndGetResponse(asynchronousResult), HttpWebResponse)
' Read the response into a Stream object.
Dim responseStream As Stream = myRequestState.response.GetResponseStream()
myRequestState.streamResponse = responseStream
' Begin the Reading of the contents of the HTML page and print it to the console.
Dim asynchronousInputRead As IAsyncResult = responseStream.BeginRead(myRequestState.BufferRead, 0, BUFFER_SIZE, AddressOf ReadCallBack, myRequestState)
Catch e As WebException
Console.WriteLine(ControlChars.Cr + "Exception raised!")
Console.WriteLine(ControlChars.Cr + "Message:{0}", e.Message)
Console.WriteLine(ControlChars.Cr + "Status:{0}", e.Status)
End Try
End Sub ' RespCallback
Private Shared Sub ReadCallBack(asyncResult As IAsyncResult)
Try
Dim myRequestState As RequestState = CType(asyncResult.AsyncState, RequestState)
Dim responseStream As Stream = myRequestState.streamResponse
Dim read As Integer = responseStream.EndRead(asyncResult)
' Read the HTML page and then print it to the console.
If read > 0 Then
myRequestState.requestData.Append(Encoding.ASCII.GetString(myRequestState.BufferRead, 0, read))
Dim asynchronousResult As IAsyncResult = responseStream.BeginRead(myRequestState.BufferRead, 0, BUFFER_SIZE, AddressOf ReadCallBack, myRequestState)
Else
Console.WriteLine(ControlChars.Cr + "The contents of the Html page are : ")
If myRequestState.requestData.Length > 1 Then
Dim stringContent As String
stringContent = myRequestState.requestData.ToString()
Console.WriteLine(stringContent)
End If
Console.WriteLine("Press any key to continue..........")
Console.ReadLine()
responseStream.Close()
allDone.Set()
End If
Catch e As WebException
Console.WriteLine(ControlChars.Cr + "Exception raised!")
Console.WriteLine(ControlChars.Cr + "Message:{0}", e.Message)
Console.WriteLine(ControlChars.Cr + "Status:{0}", e.Status)
End Try
End Sub ' ReadCallBack
try
{
// Create a HttpWebrequest object to the desired URL.
HttpWebRequest myHttpWebRequest1= (HttpWebRequest)WebRequest.Create("http://www.contoso.com");
// Create an instance of the RequestState and assign the previous myHttpWebRequest1
// object to it's request field.
RequestState myRequestState = new RequestState();
myRequestState.request = myHttpWebRequest1;
// Start the asynchronous request.
IAsyncResult result=
(IAsyncResult) myHttpWebRequest1.BeginGetResponse(new AsyncCallback(RespCallback),myRequestState);
allDone.WaitOne();
// Release the HttpWebResponse resource.
myRequestState.response.Close();
}
catch(WebException e)
{
Console.WriteLine("\nException raised!");
Console.WriteLine("\nMessage:{0}",e.Message);
Console.WriteLine("\nStatus:{0}",e.Status);
Console.WriteLine("Press any key to continue..........");
}
catch(Exception e)
{
Console.WriteLine("\nException raised!");
Console.WriteLine("Source :{0} " , e.Source);
Console.WriteLine("Message :{0} " , e.Message);
Console.WriteLine("Press any key to continue..........");
Console.Read();
}
}
private static void RespCallback(IAsyncResult asynchronousResult)
{
try
{
// State of request is asynchronous.
RequestState myRequestState=(RequestState) asynchronousResult.AsyncState;
HttpWebRequest myHttpWebRequest2=myRequestState.request;
myRequestState.response = (HttpWebResponse) myHttpWebRequest2.EndGetResponse(asynchronousResult);
// Read the response into a Stream object.
Stream responseStream = myRequestState.response.GetResponseStream();
myRequestState.streamResponse=responseStream;
// Begin the Reading of the contents of the HTML page and print it to the console.
IAsyncResult asynchronousInputRead = responseStream.BeginRead(myRequestState.BufferRead, 0, BUFFER_SIZE, new AsyncCallback(ReadCallBack), myRequestState);
}
catch(WebException e)
{
Console.WriteLine("\nException raised!");
Console.WriteLine("\nMessage:{0}",e.Message);
Console.WriteLine("\nStatus:{0}",e.Status);
}
}
private static void ReadCallBack(IAsyncResult asyncResult)
{
try
{
RequestState myRequestState = (RequestState)asyncResult.AsyncState;
Stream responseStream = myRequestState.streamResponse;
int read = responseStream.EndRead( asyncResult );
// Read the HTML page and then print it to the console.
if (read > 0)
{
myRequestState.requestData.Append(Encoding.ASCII.GetString(myRequestState.BufferRead, 0, read));
IAsyncResult asynchronousResult = responseStream.BeginRead( myRequestState.BufferRead, 0, BUFFER_SIZE, new AsyncCallback(ReadCallBack), myRequestState);
}
else
{
Console.WriteLine("\nThe contents of the Html page are : ");
if(myRequestState.requestData.Length>1)
{
string stringContent;
stringContent = myRequestState.requestData.ToString();
Console.WriteLine(stringContent);
}
Console.WriteLine("Press any key to continue..........");
Console.ReadLine();
responseStream.Close();
allDone.Set();
}
}
catch(WebException e)
{
Console.WriteLine("\nException raised!");
Console.WriteLine("\nMessage:{0}",e.Message);
Console.WriteLine("\nStatus:{0}",e.Status);
}
}
static void RespCallback( IAsyncResult^ asynchronousResult )
{
try
{
// State of request is asynchronous.
RequestState^ myRequestState = dynamic_cast<RequestState^>(asynchronousResult->AsyncState);
HttpWebRequest^ myHttpWebRequest2 = myRequestState->request;
myRequestState->response = dynamic_cast<HttpWebResponse^>(myHttpWebRequest2->EndGetResponse( asynchronousResult ));
// Read the response into a Stream object.
Stream^ responseStream = myRequestState->response->GetResponseStream();
myRequestState->streamResponse = responseStream;
// Begin the Reading of the contents of the HTML page and print it to the console.
IAsyncResult^ asynchronousInputRead = responseStream->BeginRead( myRequestState->BufferRead, 0, BUFFER_SIZE, gcnew AsyncCallback( ReadCallBack ), myRequestState );
}
catch ( WebException^ e )
{
Console::WriteLine( "\nException raised!" );
Console::WriteLine( "\nMessage: {0}", e->Message );
Console::WriteLine( "\nStatus: {0}", e->Status );
}
}
static void ReadCallBack( IAsyncResult^ asyncResult )
{
try
{
RequestState^ myRequestState = dynamic_cast<RequestState^>(asyncResult->AsyncState);
Stream^ responseStream = myRequestState->streamResponse;
int read = responseStream->EndRead( asyncResult );
// Read the HTML page and then print it to the console.
if ( read > 0 )
{
myRequestState->requestData->Append( Encoding::ASCII->GetString( myRequestState->BufferRead, 0, read ) );
IAsyncResult^ asynchronousResult = responseStream->BeginRead( myRequestState->BufferRead, 0, BUFFER_SIZE, gcnew AsyncCallback( ReadCallBack ), myRequestState );
}
else
{
Console::WriteLine( "\nThe contents of the Html page are : " );
if ( myRequestState->requestData->Length > 1 )
{
String^ stringContent;
stringContent = myRequestState->requestData->ToString();
Console::WriteLine( stringContent );
}
Console::WriteLine( "Press any key to continue.........." );
Console::ReadLine();
responseStream->Close();
allDone->Set();
}
}
catch ( WebException^ e )
{
Console::WriteLine( "\nException raised!" );
Console::WriteLine( "\nMessage: {0}", e->Message );
Console::WriteLine( "\nStatus: {0}", e->Status );
}
}
};
int main()
{
try
{
// Create a HttpWebrequest object to the desired URL.
HttpWebRequest^ myHttpWebRequest1 = dynamic_cast<HttpWebRequest^>(WebRequest::Create( "http://www.contoso.com" ));
// Create an instance of the RequestState and assign the previous myHttpWebRequest1
// object to its request field.
RequestState^ myRequestState = gcnew RequestState;
myRequestState->request = myHttpWebRequest1;
// Start the asynchronous request.
IAsyncResult^ result = dynamic_cast<IAsyncResult^>(myHttpWebRequest1->BeginGetResponse( gcnew AsyncCallback( HttpWebRequest_BeginGetResponse::RespCallback ), myRequestState ));
HttpWebRequest_BeginGetResponse::allDone->WaitOne();
// Release the HttpWebResponse resource.
myRequestState->response->Close();
}
catch ( WebException^ e )
{
Console::WriteLine( "\nException raised!" );
Console::WriteLine( "\nMessage: {0}", e->Message );
Console::WriteLine( "\nStatus: {0}", e->Status );
Console::WriteLine( "Press any key to continue.........." );
}
catch ( Exception^ e )
{
Console::WriteLine( "\nException raised!" );
Console::WriteLine( "Source : {0} ", e->Source );
Console::WriteLine( "Message : {0} ", e->Message );
Console::WriteLine( "Press any key to continue.........." );
Console::Read();
}
}
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
.NET Compact Framework
Supported in: 3.5, 2.0, 1.0
Reference