WebHeaderCollection.IsRestricted 方法

参考

定义

命名空间:: System.Net

程序集:: System.Net.WebHeaderCollection.dll

程序集:: System.dll

程序集:: netstandard.dll

重要

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测试是否能够设置指定的 HTTP 标头。

重载

IsRestricted(String)	测试是否能够为请求设置指定的 HTTP 标头。
IsRestricted(String, Boolean)	测试是否能够为请求或响应设置指定的 HTTP 标头。

IsRestricted(String)

Source:: WebHeaderCollection.cs

Source:: WebHeaderCollection.cs

Source:: WebHeaderCollection.cs

测试是否能够为请求设置指定的 HTTP 标头。

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

参数

headerName: String

要测试的标头。

Boolean

如果标头是受限制的，则为 true；否则为 false。

例外

ArgumentNullException

headerName 是 null 或 Empty。

ArgumentException

headerName 包含无效字符。

示例

以下示例检查 IsRestricted 属性以查看是否禁止设置任何标头。

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

注解

方法 IsRestricted 返回 true 以指示标头受到限制，必须使用属性而不是直接设置标头，或者由系统设置。受限制的标头包括：

Accept
连接
Content-Length
Content-Type
Date
Expect
主机
If-Modified-Since
范围
Referer
Transfer-Encoding
User-Agent
Proxy-Connection

适用于

IsRestricted(String, Boolean)

Source:: WebHeaderCollection.cs

Source:: WebHeaderCollection.cs

Source:: WebHeaderCollection.cs

测试是否能够为请求或响应设置指定的 HTTP 标头。

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

参数

headerName: String