HttpWebRequest::EndGetRequestStream Method (IAsyncResult)
Ends an asynchronous request for a Stream object to use to write data.
Assembly: System (in System.dll)
Parameters
- asyncResult
- Type: System::IAsyncResult
The pending request for a stream.
| Exception | Condition |
|---|---|
| ArgumentNullException | asyncResult is nullptr. |
| IOException | The request did not complete, and no stream is available. |
| ArgumentException | asyncResult was not returned by the current instance from a call to BeginGetRequestStream. |
| InvalidOperationException | This method was called previously using asyncResult. |
| WebException | Abort was previously called. -or- An error occurred while processing the request. |
The EndGetRequestStream method completes an asynchronous request for a stream that was started by the BeginGetRequestStream method. After the Stream object has been returned, you can send data with the HttpWebRequest by using the Stream::Write method.
Note |
|---|
You must set the value of the ContentLength property before writing data to the stream. |
Caution |
|---|
You must call the Stream::Close method to close the stream and release the connection for reuse. Failure to close the stream causes 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 EndGetRequestStream method to end an asynchronous request for a stream instance.
#using <System.dll> using namespace System; using namespace System::Net; using namespace System::IO; using namespace System::Text; using namespace System::Threading; ref class HttpWebRequestBeginGetRequest { public: static ManualResetEvent^ allDone = gcnew ManualResetEvent( false ); static void Main() { // Create a new HttpWebRequest object. HttpWebRequest^ request = dynamic_cast<HttpWebRequest^>(WebRequest::Create( "http://www.contoso.com/example.aspx" )); // Set the ContentType property. request->ContentType = "application/x-www-form-urlencoded"; // Set the Method property to 'POST' to post data to the Uri. request->Method = "POST"; // Start the asynchronous operation. AsyncCallback^ del = gcnew AsyncCallback(GetRequestStreamCallback); request->BeginGetRequestStream( del, request ); // Keep the main thread from continuing while the asynchronous // operation completes. A real world application // could do something useful such as updating its user interface. allDone->WaitOne(); } private: static void GetRequestStreamCallback(IAsyncResult^ asynchronousResult) { HttpWebRequest^ request = dynamic_cast<HttpWebRequest^>(asynchronousResult->AsyncState); // End the operation Stream^ postStream = request->EndGetRequestStream(asynchronousResult); Console::WriteLine("Please enter the input data to be posted:"); String^ postData = Console::ReadLine(); // Convert the string into a byte array. array<Byte>^ByteArray = Encoding::UTF8->GetBytes(postData); // Write to the request stream. postStream->Write(ByteArray, 0, postData->Length); postStream->Close(); // Start the asynchronous operation to get the response AsyncCallback^ del = gcnew AsyncCallback(GetResponseCallback); request->BeginGetResponse(del, request); } static void GetResponseCallback(IAsyncResult^ asynchronousResult) { HttpWebRequest^ request = dynamic_cast<HttpWebRequest^>(asynchronousResult->AsyncState); // End the operation HttpWebResponse^ response = dynamic_cast<HttpWebResponse^>(request->EndGetResponse(asynchronousResult)); Stream^ streamResponse = response->GetResponseStream(); StreamReader^ streamRead = gcnew StreamReader(streamResponse); String^ responseString = streamRead->ReadToEnd(); Console::WriteLine(responseString); // Close the stream object streamResponse->Close(); streamRead->Close(); // Release the HttpWebResponse response->Close(); allDone->Set(); } }; void main() { HttpWebRequestBeginGetRequest::Main(); }
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.
Note