WebHeaderCollection.IsRestricted WebHeaderCollection.IsRestricted WebHeaderCollection.IsRestricted WebHeaderCollection.IsRestricted Method

Definition

Tests whether the specified HTTP header can be set.

Overloads

IsRestricted(String) IsRestricted(String) IsRestricted(String) IsRestricted(String)

Tests whether the specified HTTP header can be set for the request.

IsRestricted(String, Boolean) IsRestricted(String, Boolean) IsRestricted(String, Boolean) IsRestricted(String, Boolean)

Tests whether the specified HTTP header can be set for the request or the response.

IsRestricted(String) IsRestricted(String) IsRestricted(String) IsRestricted(String)

Tests whether the specified HTTP header can be set for the request.

public:
 static bool IsRestricted(System::String ^ headerName);
public static bool IsRestricted (string headerName);
static member IsRestricted : string -> bool
Public Shared Function IsRestricted (headerName As String) As Boolean

Parameters

headerName
String String String String

The header to test.

Returns

true if the header is restricted; otherwise false.

Exceptions

Examples

The following example checks the IsRestricted property to see if any headers are prohibited from being set.

try
{
   // Create a web request for S"www.msn.com".
   HttpWebRequest^ myHttpWebRequest = dynamic_cast<HttpWebRequest^>(WebRequest::Create( "http://www.msn.com" ));

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

   // Get the headers associated with the response.
   WebHeaderCollection^ myWebHeaderCollection = myHttpWebResponse->Headers;
   for ( int i = 0; i < myWebHeaderCollection->Count; i++ )
   {
      // Check if the first response header is restriced.
      if ( WebHeaderCollection::IsRestricted( dynamic_cast<String^>(myWebHeaderCollection->AllKeys[ i ]) ) )
               Console::WriteLine( "' {0}' is a restricted header", myWebHeaderCollection->AllKeys[ i ] );
      else
               Console::WriteLine( "' {0}' is not a restricted header", myWebHeaderCollection->AllKeys[ i ] );
   }
   myHttpWebResponse->Close();
}
catch ( WebException^ e ) 
{
   Console::WriteLine( "\nWebException is thrown.\nMessage is: {0}", e->Message );
   if ( e->Status == WebExceptionStatus::ProtocolError )
   {
      Console::WriteLine( "Status Code : {0}", (dynamic_cast<HttpWebResponse^>(e->Response))->StatusCode );
      Console::WriteLine( "Status Description : {0}", (dynamic_cast<HttpWebResponse^>(e->Response))->StatusDescription );
      Console::WriteLine( "Server : {0}", (dynamic_cast<HttpWebResponse^>(e->Response))->Server );
   }
}
catch ( Exception^ e ) 
{
   Console::WriteLine( "Exception is thrown. Message is : {0}", e->Message );
}
	try {
		// Create a web request for "www.msn.com".
	 	HttpWebRequest myHttpWebRequest = (HttpWebRequest) WebRequest.Create("http://www.msn.com");

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

		// Get the headers associated with the response.
		WebHeaderCollection myWebHeaderCollection = myHttpWebResponse.Headers;
		
		for (int i = 0; i < myWebHeaderCollection.Count;i++)	
		{
 			// Check if the first response header is restricted.
		if(WebHeaderCollection.IsRestricted(myWebHeaderCollection.AllKeys[i]))
			Console.WriteLine("'{0}' is a restricted header", myWebHeaderCollection.AllKeys[i]);
		else
			Console.WriteLine("'{0}' is not a restricted header", myWebHeaderCollection.AllKeys[i]);
		}
		myHttpWebResponse.Close();
	}
	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);
	}

}
   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 associated response for the above request.
           Dim myHttpWebResponse As HttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)
           
           'Get the headers associated with the response.
           Dim myWebHeaderCollection As WebHeaderCollection = myHttpWebResponse.Headers
           
           'Check if the first response header is restricted.
    dim i as integer
    for i =0 to myWebHeaderCollection.Count-1
            If WebHeaderCollection.IsRestricted(myWebHeaderCollection.AllKeys(i)) Then
                Console.WriteLine("'{0}' is a restricted header", myWebHeaderCollection.AllKeys(i))
            Else
                Console.WriteLine("'{0}' is not a restricted header", myWebHeaderCollection.AllKeys(i))
            End If 
    next
       myHttpWebResponse.Close()
       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

Remarks

The IsRestricted method returns true to indicate that a header is restricted and must be set using properties instead of directly or is set by the system. The restricted headers are:

  • Accept

  • Connection

  • Content-Length

  • Content-Type

  • Date

  • Expect

  • Host

  • If-Modified-Since

  • Range

  • Referer

  • Transfer-Encoding

  • User-Agent

  • Proxy-Connection

IsRestricted(String, Boolean) IsRestricted(String, Boolean) IsRestricted(String, Boolean) IsRestricted(String, Boolean)

Tests whether the specified HTTP header can be set for the request or the response.

public:
 static bool IsRestricted(System::String ^ headerName, bool response);
public static bool IsRestricted (string headerName, bool response);
static member IsRestricted : string * bool -> bool
Public Shared Function IsRestricted (headerName As String, response As Boolean) As Boolean

Parameters

headerName
String String String String

The header to test.

response
Boolean Boolean Boolean Boolean

Does the Framework test the response or the request?

Returns

true if the header is restricted; otherwise, false.

Exceptions

Examples

The following example checks the IsRestricted property to see if any request headers are prohibited from being set.

try
{
   // Create a web request for S"www.msn.com".
   HttpWebRequest^ myHttpWebRequest = dynamic_cast<HttpWebRequest^>(WebRequest::Create( "http://www.msn.com" ));

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

   // Get the headers associated with the response.
   WebHeaderCollection^ myWebHeaderCollection = myHttpWebResponse->Headers;
   for ( int i = 0; i < myWebHeaderCollection->Count; i++ )
   {
      // Check if the first response header is restriced.
      if ( WebHeaderCollection::IsRestricted( dynamic_cast<String^>(myWebHeaderCollection->AllKeys[ i ]) ) )
               Console::WriteLine( "' {0}' is a restricted header", myWebHeaderCollection->AllKeys[ i ] );
      else
               Console::WriteLine( "' {0}' is not a restricted header", myWebHeaderCollection->AllKeys[ i ] );
   }
   myHttpWebResponse->Close();
}
catch ( WebException^ e ) 
{
   Console::WriteLine( "\nWebException is thrown.\nMessage is: {0}", e->Message );
   if ( e->Status == WebExceptionStatus::ProtocolError )
   {
      Console::WriteLine( "Status Code : {0}", (dynamic_cast<HttpWebResponse^>(e->Response))->StatusCode );
      Console::WriteLine( "Status Description : {0}", (dynamic_cast<HttpWebResponse^>(e->Response))->StatusDescription );
      Console::WriteLine( "Server : {0}", (dynamic_cast<HttpWebResponse^>(e->Response))->Server );
   }
}
catch ( Exception^ e ) 
{
   Console::WriteLine( "Exception is thrown. Message is : {0}", e->Message );
}
	try {
		// Create a web request for "www.msn.com".
	 	HttpWebRequest myHttpWebRequest = (HttpWebRequest) WebRequest.Create("http://www.msn.com");

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

		// Get the headers associated with the response.
		WebHeaderCollection myWebHeaderCollection = myHttpWebResponse.Headers;
		
		for (int i = 0; i < myWebHeaderCollection.Count;i++)	
		{
 			// Check if the first response header is restricted.
		if(WebHeaderCollection.IsRestricted(myWebHeaderCollection.AllKeys[i]))
			Console.WriteLine("'{0}' is a restricted header", myWebHeaderCollection.AllKeys[i]);
		else
			Console.WriteLine("'{0}' is not a restricted header", myWebHeaderCollection.AllKeys[i]);
		}
		myHttpWebResponse.Close();
	}
	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);
	}

}
   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 associated response for the above request.
           Dim myHttpWebResponse As HttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)
           
           'Get the headers associated with the response.
           Dim myWebHeaderCollection As WebHeaderCollection = myHttpWebResponse.Headers
           
           'Check if the first response header is restricted.
    dim i as integer
    for i =0 to myWebHeaderCollection.Count-1
            If WebHeaderCollection.IsRestricted(myWebHeaderCollection.AllKeys(i)) Then
                Console.WriteLine("'{0}' is a restricted header", myWebHeaderCollection.AllKeys(i))
            Else
                Console.WriteLine("'{0}' is not a restricted header", myWebHeaderCollection.AllKeys(i))
            End If 
    next
       myHttpWebResponse.Close()
       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

Remarks

The IsRestricted method returns true to indicate that a request or response header is restricted and must be set using properties instead of directly or is set by the system. The restricted headers are:

  • Accept

  • Connection

  • Content-Length

  • Content-Type

  • Date

  • Expect

  • Host

  • If-Modified-Since

  • Range

  • Referer

  • Transfer-Encoding

  • User-Agent

  • Proxy-Connection

Applies to