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WebHeaderCollection.Add Method (String, String)

Inserts a header with the specified name and value into the collection.

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

Public Overrides Sub Add ( _
	name As String, _
	value As String _
Dim instance As WebHeaderCollection 
Dim name As String 
Dim value As String

instance.Add(name, value)


Type: System.String

The header to add to the collection.

Type: System.String

The content of the header.


name is Nothing, Empty, or contains invalid characters.


name is a restricted header that must be set with a property setting.


value contains invalid characters.


The length of value is greater than 65535.

If the header specified in name does not exist, the Add method inserts a new header into the list of header name/value pairs.

If the header specified in name is already present, value is added to the existing comma-separated list of values associated with name.

The following example adds a name/value pair to a WebHeaderCollection using the Add Method.

    Public Shared Sub Main()

            '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

   	    Console.WriteLine("Configuring Webrequest to accept Danish and English language using 'Add' method")

	    'Add the Accept-Language header (for Danish) in the request.

            'Include English in the Accept-Langauge header. 
            myWebHeaderCollection.Add("Accept-Language","en;q" + ChrW(61) + "0.8")

            'Get the associated response for the above request. 
            Dim myHttpWebResponse As HttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)

            'Print the headers for the request.
        'Catch exception if trying to add a restricted header. 
        Catch e As ArgumentException
        Catch e As WebException
            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
        End Try 
    End Sub 'Main
try {
   //Create a web request for S"www.msn.com".
   HttpWebRequest* myHttpWebRequest = 
      dynamic_cast<HttpWebRequest*> (WebRequest::Create(S"http://www.msn.com"));

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

   Console::WriteLine(S"Configuring Webrequest to accept Danish and English language using 'Add' method");

   //Add the Accept-Language header (for Danish) in the request.

   //Include English in the Accept-Langauge header.

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

   //Print the headers for the request.
//Catch exception if trying to add a restricted header.
catch(ArgumentException* e) {
} catch (WebException* e) {
   Console::WriteLine(S"\nWebException is thrown. \nMessage is : {0}", e->Message);
   if (e->Status == WebExceptionStatus::ProtocolError) {
      Console::WriteLine(S"Status Code : {0}", 
      Console::WriteLine(S"Status Description : {0}", 
      Console::WriteLine(S"Server : {0}", 
} catch (Exception* e) {
   Console::WriteLine(S"Exception is thrown. Message is : {0}", e->Message);

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

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