WebRequest.Proxy 属性

定义

在后代类中重写时,获取或设置用于访问此 Internet 资源的网络代理。

public:
 virtual property System::Net::IWebProxy ^ Proxy { System::Net::IWebProxy ^ get(); void set(System::Net::IWebProxy ^ value); };
public virtual System.Net.IWebProxy Proxy { get; set; }
public virtual System.Net.IWebProxy? Proxy { get; set; }
member this.Proxy : System.Net.IWebProxy with get, set
Public Overridable Property Proxy As IWebProxy

属性值

用于访问 Internet 资源的 IWebProxy

例外

如果未在子代类中重写属性,则会尝试获取或设置该属性。

示例

以下示例显示当前的网络代理地址,并允许用户分配新的网络代理地址和端口号。

// Create a new request to the mentioned URL.
WebRequest^ myWebRequest = WebRequest::Create( "http://www.contoso.com" );

WebProxy^ myProxy = gcnew WebProxy;
// Obtain the Proxy Prperty of the  Default browser.
myProxy = (WebProxy^)(myWebRequest->Proxy);

// Print myProxy address to the console.
Console::WriteLine( "\nThe actual default Proxy settings are {0}", myProxy->Address );
try
{
   Console::WriteLine( "\nPlease enter the new Proxy Address to be set " );
   Console::WriteLine( "The format of the address should be http://proxyUriAddress:portaddress" );
   Console::WriteLine( "Example:http://proxyadress.com:8080" );
   String^ proxyAddress;
   proxyAddress = Console::ReadLine();

   if ( proxyAddress->Length == 0 )
   {
      myWebRequest->Proxy = myProxy;
   }
   else
   {
      Console::WriteLine( "\nPlease enter the Credentials" );
      Console::WriteLine( "Username:" );
      String^ username;
      username = Console::ReadLine();
      Console::WriteLine( "\nPassword:" );
      String^ password;
      password = Console::ReadLine();
      
      // Create a new Uri object.
      Uri^ newUri = gcnew Uri( proxyAddress );
      
      // Associate the new Uri object to the myProxy object.
      myProxy->Address = newUri;
      
      // Create a NetworkCredential object and is assign to the Credentials
      // property of the Proxy object.
      myProxy->Credentials = gcnew NetworkCredential( username,password );
      myWebRequest->Proxy = myProxy;
   }
   Console::WriteLine( "\nThe Address of the  new Proxy settings are {0}", myProxy->Address );
   WebResponse^ myWebResponse = myWebRequest->GetResponse();
   
   // Print the  HTML contents of the page to the console.
   Stream^ streamResponse = myWebResponse->GetResponseStream();
   StreamReader^ streamRead = gcnew StreamReader( streamResponse );
   array<Char>^ readBuff = gcnew array<Char>(256);
   int count = streamRead->Read( readBuff, 0, 256 );
   Console::WriteLine( "\nThe contents of the Html pages are :" );
   while ( count > 0 )
   {
      String^ outputData = gcnew String( readBuff,0,count );
      Console::Write( outputData );
      count = streamRead->Read( readBuff, 0, 256 );
   }
   
   // Close the Stream object.
   streamResponse->Close();
   streamRead->Close();
   
   // Release the HttpWebResponse Resource.
   myWebResponse->Close();
   Console::WriteLine( "\nPress any key to continue........." );
   Console::Read();
}
catch ( UriFormatException^ e ) 
{
   Console::WriteLine( "\nUriFormatException is thrown->Message is {0}", e->Message );
   Console::WriteLine( "\nThe format of the myProxy address you entered is invalid" );
   Console::WriteLine( "\nPress any key to continue........." );
   Console::Read();
}
   // Create a new request to the mentioned URL.				
   WebRequest myWebRequest=WebRequest.Create("http://www.contoso.com");

   WebProxy myProxy=new WebProxy();
   // Obtain the Proxy Prperty of the  Default browser.  
   myProxy=(WebProxy)myWebRequest.Proxy;

   // Print myProxy address to the console.
   Console.WriteLine("\nThe actual default Proxy settings are {0}",myProxy.Address);
try
   {
       Console.WriteLine("\nPlease enter the new Proxy Address to be set ");
       Console.WriteLine("The format of the address should be http://proxyUriAddress:portaddress");
       Console.WriteLine("Example:http://proxyadress.com:8080");
       string proxyAddress;
       proxyAddress =Console.ReadLine();

       if(proxyAddress.Length==0)
       {
           myWebRequest.Proxy=myProxy;
       }
       else
       {
           Console.WriteLine("\nPlease enter the Credentials");
           Console.WriteLine("Username:");
           string username;
           username =Console.ReadLine();
           Console.WriteLine("\nPassword:");
           string password;
           password =Console.ReadLine();

           // Create a new Uri object.
           Uri newUri=new Uri(proxyAddress);

           // Associate the new Uri object to the myProxy object.
           myProxy.Address=newUri;

           // Create a NetworkCredential object and is assign to the Credentials property of the Proxy object.
           myProxy.Credentials=new NetworkCredential(username,password);
           myWebRequest.Proxy=myProxy;
       }
       Console.WriteLine("\nThe Address of the  new Proxy settings are {0}",myProxy.Address);
       WebResponse myWebResponse=myWebRequest.GetResponse();

       // Print the  HTML contents of the page to the console.
       Stream streamResponse=myWebResponse.GetResponseStream();
       StreamReader streamRead = new StreamReader( streamResponse );
       Char[] readBuff = new Char[256];
       int count = streamRead.Read( readBuff, 0, 256 );
       Console.WriteLine("\nThe contents of the Html pages are :");	
       while (count > 0) 
       {
           String outputData = new String(readBuff, 0, count);
           Console.Write(outputData);
           count = streamRead.Read(readBuff, 0, 256);
       }

       // Close the Stream object.
       streamResponse.Close();
       streamRead.Close();

       // Release the HttpWebResponse Resource.
       myWebResponse.Close();
       Console.WriteLine("\nPress any key to continue.........");
       Console.Read();				
   }
   catch(UriFormatException e)
   {
       Console.WriteLine("\nUriFormatException is thrown.Message is {0}",e.Message);
       Console.WriteLine("\nThe format of the myProxy address you entered is invalid");
       Console.WriteLine("\nPress any key to continue.........");
       Console.Read();
   }

  ' Create a new request to the mentioned URL.				
  Dim myWebRequest As WebRequest = WebRequest.Create("http://www.contoso.com")
  Dim myProxy As New WebProxy()

  ' Obtain the Proxy Prperty of the  Default browser. 
   myProxy = CType(myWebRequest.Proxy, WebProxy)

  ' Print myProxy address to the console.
  Console.WriteLine(ControlChars.Cr + "The actual default Proxy settings are {0}", myProxy.Address)

  Try
      Console.WriteLine(ControlChars.Cr + "Please enter the new Proxy Address to be set ")
      Console.WriteLine("The format of the address should be http://proxyUriAddress:portaddress")
      Console.WriteLine("Example:http://moon.proxy.com:8080")
      Dim proxyAddress As String
      proxyAddress = Console.ReadLine()

      If proxyAddress.Length = 0 Then
          myWebRequest.Proxy = myProxy
      Else
          Console.WriteLine(ControlChars.Cr + "Please enter the Credentials")
          Console.WriteLine("Username:")
          Dim username As String
          username = Console.ReadLine()
          Console.WriteLine(ControlChars.Cr + "Password:")
          Dim password As String
          password = Console.ReadLine()

         ' Create a new Uri object.
          Dim newUri As New Uri(proxyAddress)

          ' Associate the new Uri object to the myProxy object.
          myProxy.Address = newUri

          ' Create a NetworkCredential object and is assign to the Credentials property of the Proxy object.
          myProxy.Credentials = New NetworkCredential(username, password)
          myWebRequest.Proxy = myProxy
          
      End If
      Console.WriteLine(ControlChars.Cr + "The Address of the  new Proxy settings are {0}", myProxy.Address)
      Dim myWebResponse As WebResponse = myWebRequest.GetResponse()

      ' Print the  HTML contents of the page to the console.
      Dim streamResponse As Stream = myWebResponse.GetResponseStream()

      Dim streamRead As New StreamReader(streamResponse)
      Dim readBuff(256) As [Char]
      Dim count As Integer = streamRead.Read(readBuff, 0, 256)
      Console.WriteLine(ControlChars.Cr + "The contents of the Html pages are :")

      While count > 0
          Dim outputData As New [String](readBuff, 0, count)
          Console.Write(outputData)
          count = streamRead.Read(readBuff, 0, 256)

      End While

 ' Close the Stream object.
      streamResponse.Close()
streamRead.Close()

' Release the HttpWebResponse Resource.
  myWebResponse.Close()
      Console.WriteLine(ControlChars.Cr + "Press any key to continue.........")
      Console.Read()
  Catch e As UriFormatException
      Console.WriteLine(ControlChars.Cr + "{0}", e.Message)
      Console.WriteLine(ControlChars.Cr + "The format of the myProxy address you entered is invalid")
   End Try

注解

谨慎

WebRequestHttpWebRequestServicePointWebClient 已过时,不应将其用于新开发。 请改用 HttpClient

Proxy 属性标识请求用于访问 Internet 资源的网络代理。 请求是通过代理服务器发出的,而不是直接通过 Internet 资源发出。

注意

WebRequest 类是 abstract 类。 运行时 WebRequest 实例的实际行为由 WebRequest.Create 方法返回的后代类确定。 有关默认值和异常的详细信息,请参阅子代类的文档,例如 HttpWebRequestFileWebRequest

适用于

另请参阅