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


Type: System.String

The header to add to the collection.

Type: System.String

The content of the header.

Exception Condition

name is null, 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

.NET Framework
Available since 1.1
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