Export (0) Print
Expand All

WebHeaderCollection.Set Method (String, String)

Sets the specified header to the specified value.

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

'Declaration
Public Overrides Sub Set ( _
	name As String, _
	value As String _
)

Parameters

name
Type: System.String

The header to set.

value
Type: System.String

The content of the header to set.

ExceptionCondition
ArgumentNullException

name is Nothing or Empty.

ArgumentOutOfRangeException

The length of value is greater than 65535.

ArgumentException

name is a restricted header.

-or-

name or value contain invalid characters.

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

If the header specified in header is already present, value replaces the existing value.

The following example uses the Set method to set the value of an existing header.

    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 in the request.
            myWebHeaderCollection.Set("Cache-Control", "no-cache")

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

	    Console.WriteLine ("Headers after 'Set' method is used on Cache-Control :")
            'Print the headers for the request.
            PrintHeaders(myWebHeaderCollection)
            myHttpWebResponse.Close()
       'Catch exception if trying to set a restricted header. 
        Catch e As ArgumentException
            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

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

Show:
© 2014 Microsoft