HttpWebRequest::EndGetResponse Method
Ends an asynchronous request to an Internet resource.
Assembly: System (in System.dll)
Parameters
- asyncResult
- Type: System::IAsyncResult
The pending request for a response.
Return Value
Type: System.Net::WebResponseA WebResponse that contains the response from the Internet resource.
| Exception | Condition |
|---|---|
| ArgumentNullException | asyncResult is nullptr. |
| InvalidOperationException | This method was called previously using asyncResult. -or- The ContentLength property is greater than 0 but the data has not been written to the request stream. |
| WebException | Abort was previously called. -or- An error occurred while processing the request. |
| ArgumentException | asyncResult was not returned by the current instance from a call to BeginGetResponse. |
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.
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 SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Caution