HttpWebRequest.EndGetResponse(IAsyncResult) Metode
Definisi
Penting
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Mengakhiri permintaan asinkron ke sumber daya Internet.
public:
override System::Net::WebResponse ^ EndGetResponse(IAsyncResult ^ asyncResult);
public override System.Net.WebResponse EndGetResponse (IAsyncResult asyncResult);
override this.EndGetResponse : IAsyncResult -> System.Net.WebResponse
Public Overrides Function EndGetResponse (asyncResult As IAsyncResult) As WebResponse
Parameter
- asyncResult
- IAsyncResult
Permintaan tertunda untuk respons.
Mengembalikan
WebResponse yang berisi respons dari sumber daya Internet.
Pengecualian
asyncResult
null
.
Metode ini dipanggil sebelumnya menggunakan asyncResult
.
-atau-
Properti ContentLength lebih besar dari 0 tetapi data belum ditulis ke aliran permintaan.
asyncResult
tidak dikembalikan oleh instans saat ini dari panggilan ke BeginGetResponse(AsyncCallback, Object).
Contoh
Contoh kode berikut menggunakan metode EndGetResponse untuk mengakhiri permintaan asinkron untuk sumber daya Internet.
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();
}
}
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);
}
}
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
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
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
Keterangan
Hati
WebRequest
, HttpWebRequest
, ServicePoint
, dan WebClient
usang, dan Anda tidak boleh menggunakannya untuk pengembangan baru. Gunakan HttpClient sebagai gantinya.
Metode EndGetResponse menyelesaikan permintaan asinkron untuk sumber daya Internet yang dimulai dengan memanggil metode BeginGetResponse.
Hati
Anda harus memanggil metode Close untuk menutup aliran dan merilis koneksi. Kegagalan untuk melakukannya dapat menyebabkan aplikasi Anda kehabisan koneksi.
Nota
Anggota ini mengeluarkan informasi pelacakan saat Anda mengaktifkan pelacakan jaringan di aplikasi Anda. Untuk informasi selengkapnya, lihat Pelacakan Jaringan di .NET Framework.
Berlaku untuk
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