WebHeaderCollection.Remove Method

Definition

Namespace:

System.Net

Assembly:

System.Net.WebHeaderCollection.dll

Removes the specified header from the collection.

Overloads

Remove(HttpRequestHeader)	Removes the specified header from the collection.
Remove(HttpResponseHeader)	Removes the specified header from the collection.
Remove(String)	Removes the specified header from the collection.

Remove(HttpRequestHeader)

Source:

WebHeaderCollection.cs

Removes the specified header from the collection.

public:
 void Remove(System::Net::HttpRequestHeader header);

public void Remove (System.Net.HttpRequestHeader header);

override this.Remove : System.Net.HttpRequestHeader -> unit

Public Sub Remove (header As HttpRequestHeader)

Parameters

header

HttpRequestHeader

The HttpRequestHeader instance to remove from the collection.

Exceptions

InvalidOperationException

This WebHeaderCollection instance does not allow instances of HttpRequestHeader.

Remarks

Remove deletes the specified header from the collection. If the specified header does not exist, the method does nothing.

Remove(HttpResponseHeader)

Source:

WebHeaderCollection.cs

Removes the specified header from the collection.

public:
 void Remove(System::Net::HttpResponseHeader header);

public void Remove (System.Net.HttpResponseHeader header);

override this.Remove : System.Net.HttpResponseHeader -> unit

Public Sub Remove (header As HttpResponseHeader)

Parameters

header

HttpResponseHeader

The HttpResponseHeader instance to remove from the collection.

Exceptions

InvalidOperationException

This WebHeaderCollection instance does not allow instances of HttpResponseHeader.

Remarks

Remove deletes the specified header from the collection. If the specified header does not exist, the method does nothing.

Remove(String)

Source:

WebHeaderCollection.cs

Removes the specified header from the collection.

public:
 override void Remove(System::String ^ name);

public override void Remove (string name);

override this.Remove : string -> unit

Public Overrides Sub Remove (name As String)

Parameters

name

String

The name of the header to remove from the collection.

Exceptions

ArgumentNullException

name is nullEmpty.

ArgumentException

name is a restricted header.

-or-

name contains invalid characters.

Examples

The following example uses the Remove method to remove a header from the WebHeaderCollection. After the header is removed, this example prints all existing headers to the screen to prove that it has been removed.

try
{
   // Create a web request for S"www.msn.com".
   HttpWebRequest^ myHttpWebRequest = dynamic_cast<HttpWebRequest^>(WebRequest::Create( "http://www.msn.com" ));

   // Get the headers associated with the request.
   WebHeaderCollection^ myWebHeaderCollection = myHttpWebRequest->Headers;

   // Set the Cache-Control header.
   myWebHeaderCollection->Set( "Cache-Control", "no-cache" );

   // Get the associated response for the above request.
   HttpWebResponse^ myHttpWebResponse = dynamic_cast<HttpWebResponse^>(myHttpWebRequest->GetResponse());

   // Print the headers of the request to console.
   Console::WriteLine( "Print request headers after adding Cache-Control for first request:" );
   printHeaders( myHttpWebRequest->Headers );

   // Remove the Cache-Control header for the new request.
   myWebHeaderCollection->Remove( "Cache-Control" );

   // Get the response for the new request.
   myHttpWebResponse = dynamic_cast<HttpWebResponse^>(myHttpWebRequest->GetResponse());

   // Print the headers of the new request with->Item[Out] the* Cache-Control header.
   Console::WriteLine( "Print request headers after removing Cache-Control for the new request:" );
   printHeaders( myHttpWebRequest->Headers );
   myHttpWebResponse->Close();
}
// Catch exception if trying to remove a restricted header.
catch ( ArgumentException^ e ) 
{
   Console::WriteLine( "Error : Trying to remove a restricted header" );
   Console::WriteLine( "ArgumentException is thrown. Message is : {0}", e->Message );
}
catch ( WebException^ e ) 
{
   Console::WriteLine( "WebException is thrown. Message is : {0}", e->Message );
   if ( e->Status == WebExceptionStatus::ProtocolError )
   {
      Console::WriteLine( "Status Code : {0}", (dynamic_cast<HttpWebResponse^>(e->Response))->StatusCode );
      Console::WriteLine( "Status Description : {0}", (dynamic_cast<HttpWebResponse^>(e->Response))->StatusDescription );
      Console::WriteLine( "Server : {0}", (dynamic_cast<HttpWebResponse^>(e->Response))->Server );
   }
}
catch ( Exception^ e ) 
{
   Console::WriteLine( "Exception is thrown. Message is : {0}", e->Message );
}

try {
    // Create a web request for "www.msn.com".
    HttpWebRequest myHttpWebRequest = (HttpWebRequest) WebRequest.Create("http://www.msn.com");

    // Get the headers associated with the request.
    WebHeaderCollection myWebHeaderCollection = myHttpWebRequest.Headers;

    // Set the Cache-Control header.
    myWebHeaderCollection.Set("Cache-Control", "no-cache");

    // Get the associated response for the above request.
    HttpWebResponse myHttpWebResponse = (HttpWebResponse) myHttpWebRequest.GetResponse();

    // Print the headers of the request to console.
    Console.WriteLine("Print request headers after adding Cache-Control for first request:");
    printHeaders(myHttpWebRequest.Headers);

    // Remove the Cache-Control header for the new request.
    myWebHeaderCollection.Remove("Cache-Control");

    // Get the response for the new request.
    myHttpWebResponse = (HttpWebResponse) myHttpWebRequest.GetResponse();

    // Print the headers of the new request without the Cache-Control header.
    Console.WriteLine("Print request headers after removing Cache-Control for the new request:");
    printHeaders(myHttpWebRequest.Headers);
    myHttpWebResponse.Close();
}
// Catch exception if trying to remove a restricted header.
catch(ArgumentException e) {
    Console.WriteLine("Error : Trying to remove a restricted header");
    Console.WriteLine("ArgumentException is thrown. Message is :" + e.Message);
}
catch(WebException e) {
    Console.WriteLine("WebException is thrown. Message is :" + e.Message);
    if(e.Status == WebExceptionStatus.ProtocolError) {
        Console.WriteLine("Status Code : {0}", ((HttpWebResponse)e.Response).StatusCode);
        Console.WriteLine("Status Description : {0}", ((HttpWebResponse)e.Response).StatusDescription);
        Console.WriteLine("Server : {0}", ((HttpWebResponse)e.Response).Server);
    }
}
catch(Exception e) {
    Console.WriteLine("Exception is thrown. Message is :" + e.Message);
}

Public Shared Sub Main()
  Try
        'Create a web request for "www.msn.com".
        Dim myHttpWebRequest As HttpWebRequest = CType(WebRequest.Create("http://www.msn.com"), HttpWebRequest)
        
        'Get the headers associated with the request.
        Dim myWebHeaderCollection As WebHeaderCollection = myHttpWebRequest.Headers
        
        'Set the Cache-Control header.
        myWebHeaderCollection.Set("Cache-Control", "no-cache")
        
        'Get the associated response for the above request.
        Dim myHttpWebResponse As HttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)
        
        'Print the headers of the request to console.
        Console.WriteLine("Print request headers after adding Cache-Control for first request")
        printHeaders(myHttpWebRequest.Headers)
        
   
        'Remove the Cache-Control header for the new request.
        myWebHeaderCollection.Remove("Cache-Control")
        
        'Code example for "Remove" method of "WebHeaderCollection" ends here.
        'Get the response for the new request.
        myHttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)
        
        'Print the headers of the new request without the Cache-Control header.
        Console.WriteLine("Print request headers after removing Cache-Control for the new request")
        printHeaders(myHttpWebRequest.Headers)
        myHttpWebResponse.Close()
    'Catch exception if trying to remove a restricted header.
    Catch e As ArgumentException
        Console.WriteLine("Error : Trying to remove a restricted header")
        Console.WriteLine(e.Message)
    Catch e As WebException
        Console.WriteLine(e.Message)
        If e.Status = WebExceptionStatus.ProtocolError Then
            Console.WriteLine("Status Code : {0}", CType(e.Response, HttpWebResponse).StatusCode)
            Console.WriteLine("Status Description : {0}", CType(e.Response, HttpWebResponse).StatusDescription)
            Console.WriteLine("Server : {0}", CType(e.Response, HttpWebResponse).Server)
        End If
    Catch e As Exception
        Console.WriteLine(e.Message)
    End Try

End Sub

Remarks

Remove deletes the specified header from the collection. If the specified header does not exist, the method returns.