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WebRequest.Proxy Proprietà

Definizione

Quando sottoposto a override in una classe discendente, ottiene o imposta il proxy di rete da usare per accedere a questa risorsa Internet.

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

Valore della proprietà

Il IWebProxy da usare per accedere alla risorsa Internet.

Eccezioni

Qualsiasi tentativo viene effettuato per ottenere o impostare la proprietà, quando la proprietà non viene sottoposta a override in una classe discendente.

Esempio

L'esempio seguente visualizza l'indirizzo proxy di rete corrente e consente all'utente di assegnare un nuovo indirizzo proxy di rete e un numero di porta.

// 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

Commenti

Cautela

WebRequest, HttpWebRequest, ServicePointe WebClient sono obsoleti e non è consigliabile usarli per nuovi sviluppi. Usare invece HttpClient.

La proprietà Proxy identifica il proxy di rete usato dalla richiesta per accedere alla risorsa Internet. La richiesta viene effettuata tramite il server proxy anziché direttamente alla risorsa Internet.

Nota

La classe WebRequest è una classe abstract. Il comportamento effettivo delle istanze di WebRequest in fase di esecuzione è determinato dalla classe discendente restituita dal metodo WebRequest.Create. Per altre informazioni sui valori predefiniti e sulle eccezioni, vedere la documentazione per le classi discendenti, ad esempio HttpWebRequest e FileWebRequest.

Si applica a

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