WebHeaderCollection.IsRestricted Method

Reference

Definition

Namespace:: System.Net

Assembly:: System.Net.WebHeaderCollection.dll

Assembly:: System.dll

Assembly:: netstandard.dll

Important

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Tests whether the specified HTTP header can be set.

Overloads

IsRestricted(String)	Tests whether the specified HTTP header can be set for the request.
IsRestricted(String, Boolean)	Tests whether the specified HTTP header can be set for the request or the response.

IsRestricted(String)

Source:: WebHeaderCollection.cs

Source:: WebHeaderCollection.cs

Source:: WebHeaderCollection.cs

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

The header to test.

Returns

Boolean

true if the header is restricted; otherwise false.

Exceptions

ArgumentNullException

headerName is null or Empty.

ArgumentException

headerName contains invalid characters.

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

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

Applies to

IsRestricted(String, Boolean)

Source:: WebHeaderCollection.cs

Source:: WebHeaderCollection.cs

Source:: WebHeaderCollection.cs

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

The header to test.

response: Boolean

true to test the response; false to test the request.

Returns

Boolean

true if the header is restricted; otherwise, false.

Exceptions

ArgumentNullException

headerName is null or Empty.

ArgumentException

headerName contains invalid characters.

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

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

Partajați prin

WebHeaderCollection.IsRestricted Method

Definition

Overloads

IsRestricted(String)

Parameters

Returns

Exceptions

Examples

Remarks

Applies to

IsRestricted(String, Boolean)

Parameters

Returns

Exceptions

Examples

Remarks

Applies to

Resurse suplimentare