HttpListenerResponse.AppendHeader Method

Appends a value to the specified HTTP header to be sent with this response.

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

public void AppendHeader (
	string name,
	string value
public void AppendHeader (
	String name, 
	String value
public function AppendHeader (
	name : String, 
	value : String
Not applicable.



The name of the HTTP header to append value to.


The value to append to the name header.

Exception typeCondition


name is a null reference (Nothing in Visual Basic) or an empty string ("").


You are not allowed to specify a value for the specified header.


name or value contains invalid characters.


The length of value is greater than 65,535 characters.

Calling this method is equivalent to calling the Add method on the collection returned by the Headers property.

If the header specified in header does not exist, this method inserts a new header into the Headers property's collection. If header is present in the collection, this method adds value to the existing values. To replace the value of an existing header, use the AddHeader method.

Windows 98, Windows Server 2003, Windows XP Media Center 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