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Add Method (String, String)
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WebHeaderCollection.Add Method (String, String)

.NET Framework 1.1

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

[Visual Basic]
Overrides Overloads Public Sub Add( _
   ByVal name As String, _
   ByVal value As String _
)
[C#]
public override void Add(
 string name,
 string value
);
[C++]
public: void Add(
 String* name,
 String* value
);
[JScript]
public override function Add(
   name : String,
 value : String
);

Parameters

name
The header to add to the collection.
value
The content of the header.

Exceptions

Exception Type Condition
ArgumentException name is a null reference (Nothing in Visual Basic), Empty, or contains invalid characters.

-or-

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

-or-

value contains invalid characters.

Remarks

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.

Example

[Visual Basic, C#, C++] The following example adds a name/value pair to a WebHeaderCollection using the Add Method.

[Visual Basic] 
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
        
       Console.WriteLine("Configuring Webrequest to accept Danish and English language using 'Add' method")
        
    'Add the Accept-Language header (for Danish) in the request.
        myWebHeaderCollection.Add("Accept-Language:da")
        
        '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.
        printHeaders(myWebHeaderCollection)
        myHttpWebResponse.Close()
    'Catch exception if trying to add 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

[C#] 
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.Headers;

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

    //Add the Accept-Language header (for Danish) in the request.
    myWebHeaderCollection.Add("Accept-Language:da");

    //Include English in the Accept-Langauge header. 
    myWebHeaderCollection.Add("Accept-Language:en;q=0.8");

    //Get the associated response for the above request.
     HttpWebResponse myHttpWebResponse = (HttpWebResponse) myHttpWebRequest.GetResponse();

    //Print the headers for the request.
    printHeaders(myWebHeaderCollection);
    myHttpWebResponse.Close();
}
//Catch exception if trying to add a restricted header.
catch(ArgumentException e) {
    Console.WriteLine(e.Message);
}
catch(WebException e) {
    Console.WriteLine("\nWebException is thrown. \nMessage is :" + e.Message);
    if(e.Status == WebExceptionStatus.ProtocolError) {
        Console.WriteLine("Status Code : {0}", ((HttpWebResponse)e.Response).StatusCode);
        Console.WriteLine("Status Description : {0}", ((HttpWebResponse)e.Response).StatusDescription);
        Console.WriteLine("Server : {0}", ((HttpWebResponse)e.Response).Server);
    }
}
catch(Exception e) {
    Console.WriteLine("Exception is thrown. Message is :" + e.Message);
}

[C++] 
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.
   myWebHeaderCollection->Add(S"Accept-Language:da");

   //Include English in the Accept-Langauge header.
   myWebHeaderCollection->Add(S"Accept-Language:en;q=0.8");

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

   //Print the headers for the request.
   printHeaders(myWebHeaderCollection);
   myHttpWebResponse->Close();
}
//Catch exception if trying to add a restricted header.
catch(ArgumentException* e) {
   Console::WriteLine(e->Message);
} 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}", 
         __box((dynamic_cast<HttpWebResponse*>(e->Response))->StatusCode));
      Console::WriteLine(S"Status Description : {0}", 
         (dynamic_cast<HttpWebResponse*>(e->Response))->StatusDescription);
      Console::WriteLine(S"Server : {0}", 
         (dynamic_cast<HttpWebResponse*>(e->Response))->Server);
   }
} catch (Exception* e) {
   Console::WriteLine(S"Exception is thrown. Message is : {0}", e->Message);
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework, Common Language Infrastructure (CLI) Standard

See Also

WebHeaderCollection Class | WebHeaderCollection Members | System.Net Namespace | WebHeaderCollection.Add Overload List

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