Export (0) Print
Expand All

WebHeaderCollection.Remove Method (String)

Removes the specified header from the collection.

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

'Declaration
Public Overrides Sub Remove ( _
	name As String _
)
'Usage
Dim instance As WebHeaderCollection
Dim name As String

instance.Remove(name)
public void Remove (
	String name
)
public override function Remove (
	name : String
)
Not applicable.

Parameters

name

The name of the header to remove from the collection.

Exception typeCondition

ArgumentNullException

name is a null reference (Nothing in Visual Basic)Empty.

ArgumentException

name is a restricted header.

-or-

name contains invalid characters.

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

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.

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 'Main

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.
        get_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.get_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.get_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.get_Message());
}
catch (WebException e) {
    Console.WriteLine("WebException is thrown. Message is :" 
        + e.get_Message());
    if (e.get_Status().Equals(WebExceptionStatus.ProtocolError)) {
        Console.WriteLine("Status Code : {0}", ((HttpWebResponse)e.
            get_Response()).get_StatusCode());
        Console.WriteLine("Status Description : {0}", ((
            HttpWebResponse)e.get_Response()).get_StatusDescription());
        Console.WriteLine("Server : {0}", ((HttpWebResponse)(
            e.get_Response())).get_Server());
    }
}
catch (System.Exception e) {
    Console.WriteLine("Exception is thrown. Message is :" 
        + e.get_Message());
}

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

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

Community Additions

ADD
Show:
© 2015 Microsoft