WebHeaderCollection.Remove 方法

定义

命名空间:

System.Net

程序集:

System.Net.WebHeaderCollection.dll

从集合中移除指定的标头。

重载

Remove(HttpRequestHeader)	从集合中移除指定的标头。
Remove(HttpResponseHeader)	从集合中移除指定的标头。
Remove(String)	从集合中移除指定的标头。

Remove(HttpRequestHeader)

Source:

WebHeaderCollection.cs

从集合中移除指定的标头。

public:
 void Remove(System::Net::HttpRequestHeader header);

public void Remove (System.Net.HttpRequestHeader header);

override this.Remove : System.Net.HttpRequestHeader -> unit

Public Sub Remove (header As HttpRequestHeader)

参数

header

HttpRequestHeader

要从集合中移除的 HttpRequestHeader 实例。

例外

InvalidOperationException

此 WebHeaderCollection 实例不允许 HttpRequestHeader 的实例。

注解

Remove 从集合中删除指定的标头。 如果指定的标头不存在，则 该方法不执行任何工作。

Remove(HttpResponseHeader)

Source:

WebHeaderCollection.cs

从集合中移除指定的标头。

public:
 void Remove(System::Net::HttpResponseHeader header);

public void Remove (System.Net.HttpResponseHeader header);

override this.Remove : System.Net.HttpResponseHeader -> unit

Public Sub Remove (header As HttpResponseHeader)

参数

header

HttpResponseHeader

要从集合中移除的 HttpResponseHeader 实例。

例外

InvalidOperationException

此 WebHeaderCollection 实例不允许 HttpResponseHeader 的实例。

注解

Remove 从集合中删除指定的标头。 如果指定的标头不存在，则 该方法不执行任何工作。

Remove(String)

Source:

WebHeaderCollection.cs

从集合中移除指定的标头。

public:
 override void Remove(System::String ^ name);

public override void Remove (string name);

override this.Remove : string -> unit

Public Overrides Sub Remove (name As String)

参数

name

String

要从集合中移除的标头名称。

例外

ArgumentNullException

name 为 nullEmpty。

ArgumentException

name 是受限制的标头。

- 或 -

name 包含无效字符。

示例

以下示例使用 Remove 方法从 WebHeaderCollection中删除标头。 删除页眉后，本示例将所有现有页眉打印到屏幕上，以证明该页眉已被删除。

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

   // Get the headers associated with the request.
   WebHeaderCollection^ myWebHeaderCollection = myHttpWebRequest->Headers;

   // Set the Cache-Control header.
   myWebHeaderCollection->Set( "Cache-Control", "no-cache" );

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

   // Print the headers of the request to console.
   Console::WriteLine( "Print request headers after adding Cache-Control for first request:" );
   printHeaders( myHttpWebRequest->Headers );

   // Remove the Cache-Control header for the new request.
   myWebHeaderCollection->Remove( "Cache-Control" );

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

   // Print the headers of the new request with->Item[Out] the* Cache-Control header.
   Console::WriteLine( "Print request headers after removing Cache-Control for the new request:" );
   printHeaders( myHttpWebRequest->Headers );
   myHttpWebResponse->Close();
}
// Catch exception if trying to remove a restricted header.
catch ( ArgumentException^ e ) 
{
   Console::WriteLine( "Error : Trying to remove a restricted header" );
   Console::WriteLine( "ArgumentException is thrown. Message is : {0}", e->Message );
}
catch ( WebException^ e ) 
{
   Console::WriteLine( "WebException is thrown. Message 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 headers associated with the request.
    WebHeaderCollection myWebHeaderCollection = myHttpWebRequest.Headers;

    // Set the Cache-Control header.
    myWebHeaderCollection.Set("Cache-Control", "no-cache");

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

    // Print the headers of the request to console.
    Console.WriteLine("Print request headers after adding Cache-Control for first request:");
    printHeaders(myHttpWebRequest.Headers);

    // Remove the Cache-Control header for the new request.
    myWebHeaderCollection.Remove("Cache-Control");

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

    // Print the headers of the new request without the Cache-Control header.
    Console.WriteLine("Print request headers after removing Cache-Control for the new request:");
    printHeaders(myHttpWebRequest.Headers);
    myHttpWebResponse.Close();
}
// Catch exception if trying to remove a restricted header.
catch(ArgumentException e) {
    Console.WriteLine("Error : Trying to remove a restricted header");
    Console.WriteLine("ArgumentException is thrown. Message is :" + e.Message);
}
catch(WebException e) {
    Console.WriteLine("WebException is thrown. Message 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 headers associated with the request.
        Dim myWebHeaderCollection As WebHeaderCollection = myHttpWebRequest.Headers
        
        'Set the Cache-Control header.
        myWebHeaderCollection.Set("Cache-Control", "no-cache")
        
        'Get the associated response for the above request.
        Dim myHttpWebResponse As HttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)
        
        'Print the headers of the request to console.
        Console.WriteLine("Print request headers after adding Cache-Control for first request")
        printHeaders(myHttpWebRequest.Headers)
        
   
        'Remove the Cache-Control header for the new request.
        myWebHeaderCollection.Remove("Cache-Control")
        
        'Code example for "Remove" method of "WebHeaderCollection" ends here.
        'Get the response for the new request.
        myHttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)
        
        'Print the headers of the new request without the Cache-Control header.
        Console.WriteLine("Print request headers after removing Cache-Control for the new request")
        printHeaders(myHttpWebRequest.Headers)
        myHttpWebResponse.Close()
    'Catch exception if trying to remove a restricted header.
    Catch e As ArgumentException
        Console.WriteLine("Error : Trying to remove a restricted header")
        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

注解

Remove 从集合中删除指定的标头。 如果指定的标头不存在，该方法将返回 。