HttpWebRequest.Connection Eigenschaft
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Ruft den Wert des Connection
-HTTP-Headers ab oder legt ihn fest.
public:
property System::String ^ Connection { System::String ^ get(); void set(System::String ^ value); };
public string? Connection { get; set; }
public string Connection { get; set; }
member this.Connection : string with get, set
Public Property Connection As String
Eigenschaftswert
Der Wert des Connection
-HTTP-Headers. Der Standardwert ist null
.
Ausnahmen
Der Wert von Connection wird auf „Keep-Alive“ oder „Close“ festgelegt.
Beispiele
Im folgenden Codebeispiel wird die Connection -Eigenschaft verwendet, um den Wert des Verbindungs-HTTP-Headers festzulegen.
int main()
{
try
{
// Create a new HttpWebRequest object. Make sure that
// a default proxy is set if you are behind a firewall.
HttpWebRequest^ myHttpWebRequest1 = dynamic_cast<HttpWebRequest^>(WebRequest::Create( "http://www.contoso.com" ));
myHttpWebRequest1->KeepAlive = false;
// Assign the response object of HttpWebRequest to a HttpWebResponse variable.
HttpWebResponse^ myHttpWebResponse1 = dynamic_cast<HttpWebResponse^>(myHttpWebRequest1->GetResponse());
Console::WriteLine( "\nThe HTTP request Headers for the first request are: \n {0}", myHttpWebRequest1->Headers );
Console::WriteLine( "Press Enter Key to Continue.........." );
Console::Read();
Stream^ streamResponse = myHttpWebResponse1->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.......\n" );
while ( count > 0 )
{
String^ outputData = gcnew String( readBuff,0,count );
Console::Write( outputData );
count = streamRead->Read( readBuff, 0, 256 );
}
Console::WriteLine();
// Close the Stream object.
streamResponse->Close();
streamRead->Close();
// Release the resources held by response object.
myHttpWebResponse1->Close();
// Create a new HttpWebRequest object for the specified Uri.
HttpWebRequest^ myHttpWebRequest2 = dynamic_cast<HttpWebRequest^>(WebRequest::Create( "http://www.contoso.com" ));
myHttpWebRequest2->Connection = "Close";
// Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
HttpWebResponse^ myHttpWebResponse2 = dynamic_cast<HttpWebResponse^>(myHttpWebRequest2->GetResponse());
// Release the resources held by response object.
myHttpWebResponse2->Close();
Console::WriteLine( "\nThe Http RequestHeaders are \n {0}", myHttpWebRequest2->Headers );
Console::WriteLine( "\nPress 'Enter' Key to Continue........." );
Console::Read();
}
catch ( ArgumentException^ e )
{
Console::WriteLine( "\nThe second HttpWebRequest Object* has raised an Argument Exception as 'Connection' Property is set to 'Close'" );
Console::WriteLine( "\n {0}", e->Message );
}
catch ( WebException^ e )
{
Console::WriteLine( "WebException raised!" );
Console::WriteLine( "\n {0}", e->Message );
Console::WriteLine( "\n {0}", e->Status );
}
catch ( Exception^ e )
{
Console::WriteLine( "Exception raised!" );
Console::WriteLine( "Source : {0} ", e->Source );
Console::WriteLine( "Message : {0} ", e->Message );
}
}
class HttpWebRequest_Connection
{
static void Main()
{
try
{
// Create a new HttpWebRequest object.Make sure that
// a default proxy is set if you are behind a firewall.
HttpWebRequest myHttpWebRequest1 =
(HttpWebRequest)WebRequest.Create("http://www.contoso.com");
myHttpWebRequest1.KeepAlive=false;
// Assign the response object of HttpWebRequest to a HttpWebResponse variable.
HttpWebResponse myHttpWebResponse1 =
(HttpWebResponse)myHttpWebRequest1.GetResponse();
Console.WriteLine("\nThe HTTP request Headers for the first request are: \n{0}",myHttpWebRequest1.Headers);
Console.WriteLine("Press Enter Key to Continue..........");
Console.Read();
Stream streamResponse=myHttpWebResponse1.GetResponseStream();
StreamReader streamRead = new StreamReader( streamResponse );
Char[] readBuff = new Char[256];
int count = streamRead.Read( readBuff, 0, 256 );
Console.WriteLine("The contents of the Html page are.......\n");
while (count > 0)
{
String outputData = new String(readBuff, 0, count);
Console.Write(outputData);
count = streamRead.Read(readBuff, 0, 256);
}
Console.WriteLine();
// Close the Stream object.
streamResponse.Close();
streamRead.Close();
// Release the resources held by response object.
myHttpWebResponse1.Close();
// Create a new HttpWebRequest object for the specified Uri.
HttpWebRequest myHttpWebRequest2 =
(HttpWebRequest)WebRequest.Create("http://www.contoso.com");
myHttpWebRequest2.Connection="Close";
// Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
HttpWebResponse myHttpWebResponse2 =
(HttpWebResponse)myHttpWebRequest2.GetResponse();
// Release the resources held by response object.
myHttpWebResponse2.Close();
Console.WriteLine("\nThe Http RequestHeaders are \n{0}",myHttpWebRequest2.Headers);
Console.WriteLine("\nPress 'Enter' Key to Continue.........");
Console.Read();
}
catch(ArgumentException e)
{
Console.WriteLine("\nThe second HttpWebRequest object has raised an Argument Exception as 'Connection' Property is set to 'Close'");
Console.WriteLine("\n{0}",e.Message);
}
catch(WebException e)
{
Console.WriteLine("WebException raised!");
Console.WriteLine("\n{0}",e.Message);
Console.WriteLine("\n{0}",e.Status);
}
catch(Exception e)
{
Console.WriteLine("Exception raised!");
Console.WriteLine("Source :{0} " , e.Source);
Console.WriteLine("Message :{0} " , e.Message);
}
}
}
Class HttpWebRequest_Connection
Shared Sub Main()
Try
' Create a new 'HttpWebRequest' object for the specified Uri. Make sure that
' a default proxy is set if you are behind a firewall.
Dim myHttpWebRequest1 As HttpWebRequest = CType(WebRequest.Create("http://www.contoso.com"), HttpWebRequest)
myHttpWebRequest1.KeepAlive = False
' Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
Dim myHttpWebResponse1 As HttpWebResponse = CType(myHttpWebRequest1.GetResponse(), HttpWebResponse)
Console.WriteLine(ControlChars.Cr + "The HTTP request Headers for the first request are {0}", myHttpWebRequest1.Headers)
Console.WriteLine("Press Enter Key to Continue..........")
Console.Read()
Dim streamResponse As Stream = myHttpWebResponse1.GetResponseStream()
Dim streamRead As New StreamReader(streamResponse)
Dim readBuff(256) As [Char]
Dim count As Integer = streamRead.Read(readBuff, 0, 256)
Console.WriteLine("The contents of the Html page are......." + ControlChars.Cr)
While count > 0
Dim outputData As New [String](readBuff, 0, count)
Console.Write(outputData)
count = streamRead.Read(readBuff, 0, 256)
End While
' Close the Stream object.
streamResponse.Close()
streamRead.Close()
' Release the resources held by response object.
myHttpWebResponse1.Close()
Console.WriteLine()
' Create a new 'HttpWebRequest' object to the specified Uri.
Dim myHttpWebRequest2 As HttpWebRequest = CType(WebRequest.Create("http://www.contoso.com"), HttpWebRequest)
myHttpWebRequest2.Connection = "Close"
' Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
Dim myHttpWebResponse2 As HttpWebResponse = CType(myHttpWebRequest2.GetResponse(), HttpWebResponse)
' Release the resources held by response object.
myHttpWebResponse2.Close()
Console.WriteLine(ControlChars.Cr + "The Http RequestHeaders are " + ControlChars.Cr + "{0}", myHttpWebRequest2.Headers)
Console.WriteLine(ControlChars.Cr + "Press 'Enter' Key to Continue.........")
Console.Read()
Catch e As ArgumentException
Console.WriteLine(ControlChars.Cr + "The second HttpWebRequest object has raised an Argument Exception as 'Connection' Property is set to 'Close'")
Console.WriteLine(ControlChars.Cr + "{0}", e.Message)
Catch e As WebException
Console.WriteLine("WebException raised!")
Console.WriteLine(ControlChars.Cr + "{0}", e.Message)
Console.WriteLine(ControlChars.Cr + "{0}", e.Status)
Catch e As Exception
Console.WriteLine("Exception raised!")
Console.WriteLine("Source :{0} ", e.Source)
Console.WriteLine("Message : {0}", e.Message)
End Try
End Sub
End Class
Hinweise
Die Anforderung sendet die Connection -Eigenschaft als HTTP-Header an die Connection
Internetressource. Wenn der Wert der KeepAlive -Eigenschaft ist true
, wird der Wert "Keep-alive" an das Ende des Connection
Headers angefügt.
Um den Connection
HTTP-Header zu löschen, legen Sie die Connection -Eigenschaft auf fest null
.
Wenn Sie die Connection Eigenschaft ändern, nachdem die Anforderung gestartet wurde, indem Sie die GetRequestStreamMethode , BeginGetRequestStream, GetResponseoder BeginGetResponse aufrufen, löst ein aus InvalidOperationException.
Hinweis
Der Wert für diese Eigenschaft wird in der WebHeaderCollection gespeichert. Wenn WebHeaderCollection festgelegt wird, geht der Eigenschaftswert verloren.
Gilt für:
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