Export (0) Print
Expand All

HttpWebRequest.Connection Property

Gets or sets the value of the Connection HTTP header.

[Visual Basic]
Public Property Connection As String
[C#]
public string Connection {get; set;}
[C++]
public: __property String* get_Connection();
public: __property void set_Connection(String*);
[JScript]
public function get Connection() : String;
public function set Connection(String);

Property Value

The value of the Connection HTTP header. The default value is a null reference (Nothing in Visual Basic).

Exceptions

Exception Type Condition
ArgumentException The value of Connection is set to Keep-alive or Close.

Remarks

The request sends the Connection property to the Internet resource as the Connection HTTP header. If KeepAlive is true, the value "Keep-alive" is appended to the end of the Connection header.

To clear the Connection HTTP header, set the Connection property to a null reference (Nothing in Visual Basic).

Changing the Connection property after the request has been started by calling GetRequestStream, BeginGetRequestStream, GetResponse, or BeginGetResponse method will throw an InvalidOperationException.

Example

[Visual Basic, C#, C++] The following example uses the Connection property to set the value of the Connection HTTP Header.

[Visual Basic] 

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 fure wall.
      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 ' Main
End Class ' HttpWebRequest_Connection

[C#] 

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


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 fure wall.
      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);
    }
  }
}


[C++] 
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(S"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(S"\nThe HTTP request Headers for the first request are: \n {0}",
         myHttpWebRequest1->Headers);
      Console::WriteLine(S"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(S"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 =
         dynamic_cast<HttpWebRequest*>(WebRequest::Create(S"http://www.contoso.com"));
      myHttpWebRequest2->Connection=S"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(S"\nThe Http RequestHeaders are \n {0}",
         myHttpWebRequest2->Headers);
      Console::WriteLine(S"\nPress 'Enter' Key to Continue.........");
      Console::Read();
   } catch (ArgumentException* e) {
      Console::WriteLine(S"\nThe second HttpWebRequest Object* has raised an Argument Exception as 'Connection' Property is set to 'Close'");
      Console::WriteLine(S"\n {0}", e->Message);
   } catch (WebException* e) {
      Console::WriteLine(S"WebException raised!");
      Console::WriteLine(S"\n {0}", e->Message);
      Console::WriteLine(S"\n {0}", __box( e->Status));
   } catch (Exception* e) {
      Console::WriteLine(S"Exception raised!");
      Console::WriteLine(S"Source : {0} " , e->Source);
      Console::WriteLine(S"Message : {0} " , e->Message);
   }
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework, Common Language Infrastructure (CLI) Standard

See Also

HttpWebRequest Class | HttpWebRequest Members | System.Net Namespace

Show:
© 2014 Microsoft