HttpWebRequest.Connection-Eigenschaft

Artikel
08/20/2007

Ruft den Wert des Connection-HTTP-Headers ab oder legt diesen fest.

Namespace: System.Net
Assembly: System (in system.dll)

Syntax

'Declaration
Public Property Connection As String
'Usage
Dim instance As HttpWebRequest
Dim value As String

value = instance.Connection

instance.Connection = value

public string Connection { get; set; }

public:
property String^ Connection {
    String^ get ();
    void set (String^ value);
}

/** @property */
public String get_Connection ()

/** @property */
public void set_Connection (String value)

public function get Connection () : String

public function set Connection (value : String)

Eigenschaftenwert

Der Wert des Connection-HTTP-Headers. Der Standardwert ist NULL (Nothing in Visual Basic).

Ausnahmen

Ausnahmetyp	Bedingung
ArgumentException	Der Wert von Connection wird auf Keep-alive oder Close festgelegt.

Hinweise

Die Anforderung sendet die Connection-Eigenschaft als Connection-HTTP-Header an die Internetressource. Wenn der Wert der KeepAlive-Eigenschaft true ist, wird der Wert "Keep-alive" am Ende des Connection-Headers angefügt.

Legen Sie die Connection-Eigenschaft auf NULL (Nothing in Visual Basic) fest, um den Connection-HTTP-Header zu löschen.

Wenn die Connection-Eigenschaft geändert wird, nachdem die Anforderung durch den Aufruf der GetRequestStream-Methode, der BeginGetRequestStream-Methode, der GetResponse-Methode oder der BeginGetResponse-Methode gestartet wurde, wird eine InvalidOperationException ausgelöst.

Hinweis

Der Wert für diese Eigenschaft wird in der WebHeaderCollection gespeichert. Wenn WebHeaderCollection festgelegt wird, geht der Eigenschaftenwert verloren.

Beispiel

Im folgenden Codebeispiel legt die Connection-Eigenschaft den Wert für den Connection-HTTP-Header fest.

Imports System
Imports System.IO
Imports System.Net
Imports System.Text
Imports Microsoft.VisualBasic

using System;
using System.IO;
using System.Net;
using System.Text;

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( "https://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( "https://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
{
    public static void main(String[] args)
    {
        try {
            // Create a new HttpWebRequest object.Make sure that 
            // a default proxy is set if you are behind a fure wall.
            HttpWebRequest myHttpWebRequest1 = (HttpWebRequest)
                (WebRequest.Create("https://www.contoso.com"));
            myHttpWebRequest1.set_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.get_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("https://www.contoso.com"));
            myHttpWebRequest2.set_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.get_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.get_Message());
        }
        catch (WebException e) {
            Console.WriteLine("WebException raised!");
            Console.WriteLine("\n{0}", e.get_Message());
            Console.WriteLine("\n{0}", e.get_Status());
        }
        catch (System.Exception e) {
            Console.WriteLine("Exception raised!");
            Console.WriteLine("Source :{0} ", e.get_Source());
            Console.WriteLine("Message :{0} ", e.get_Message());
        }
    } //main
} //HttpWebRequest_Connection

import System.*;
import System.IO.*;
import System.Net.*;
import System.Text.*;

class HttpWebRequest_Connection
{
    public static void main(String[] args)
    {
        try {
            // Create a new HttpWebRequest object.Make sure that 
            // a default proxy is set if you are behind a fure wall.
            HttpWebRequest myHttpWebRequest1 = (HttpWebRequest)
                (WebRequest.Create("https://www.contoso.com"));
            myHttpWebRequest1.set_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.get_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("https://www.contoso.com"));
            myHttpWebRequest2.set_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.get_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.get_Message());
        }
        catch (WebException e) {
            Console.WriteLine("WebException raised!");
            Console.WriteLine("\n{0}", e.get_Message());
            Console.WriteLine("\n{0}", e.get_Status());
        }
        catch (System.Exception e) {
            Console.WriteLine("Exception raised!");
            Console.WriteLine("Source :{0} ", e.get_Source());
            Console.WriteLine("Message :{0} ", e.get_Message());
        }
    } //main
} //HttpWebRequest_Connection

Plattformen

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Freigeben über

HttpWebRequest.Connection-Eigenschaft

Syntax

Eigenschaftenwert

Ausnahmen

Hinweise

Beispiel

Plattformen

Versionsinformationen

.NET Framework

.NET Compact Framework

Siehe auch

Referenz

Zusätzliche Ressourcen