WebRequest.Proxy 屬性

定義

在子代類別中覆寫時,取得或設定用來存取此因特網資源的網路 Proxy。

C#
public virtual System.Net.IWebProxy Proxy { get; set; }
C#
public virtual System.Net.IWebProxy? Proxy { get; set; }

屬性值

要用來存取因特網資源的 IWebProxy

例外狀況

當屬性未在子系類別中覆寫時,會嘗試取得或設定 屬性。

範例

下列範例會顯示目前的網路 Proxy 位址,並允許使用者指派新的網路 Proxy 位址和埠號碼。

C#
   // 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();
   }

備註

警告

WebRequestHttpWebRequestServicePointWebClient 已經過時,您不應該將它們用於新的開發。 請改用 HttpClient

Proxy 屬性會識別要求用來存取因特網資源的網路 Proxy。 要求是透過 Proxy 伺服器進行,而不是直接傳送至因特網資源。

注意

WebRequest 類別是 abstract 類別。 運行時間 WebRequest 實例的實際行為是由 WebRequest.Create 方法所傳回的子代類別所決定。 如需預設值和例外狀況的詳細資訊,請參閱子代類別的檔,例如 HttpWebRequestFileWebRequest

適用於

產品 版本
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1
UWP 10.0

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