HttpWebRequest.Proxy 属性

  • 参考

定义

命名空间:
System.Net
程序集:
System.Net.Requests.dll
程序集:
System.dll
程序集:
netstandard.dll
Source:
HttpWebRequest.cs
Source:
HttpWebRequest.cs
Source:
HttpWebRequest.cs

获取或设置请求的代理信息。

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

属性值

IWebProxy

用于代理请求的 IWebProxy 对象。 默认值通过调用 Select 属性设置。

例外

ArgumentNullException

将 Proxy 设置为 null。

InvalidOperationException

已通过调用 GetRequestStream()、BeginGetRequestStream(AsyncCallback, Object)、GetResponse() 或 BeginGetResponse(AsyncCallback, Object) 启动请求。

SecurityException

调用方无权执行所请求的操作。

示例

下面的代码示例使用 Proxy 方法获取请求的代理信息。

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

// Obtain the 'Proxy' of the  Default browser.  
IWebProxy ^ proxy = myWebRequest->Proxy;
// Print the Proxy Url to the console.
if (proxy) 
{
    Console::WriteLine("Proxy: {0}",
        proxy->GetProxy(myWebRequest->RequestUri));
} 
else 
{
    Console::WriteLine("Proxy is null; no proxy will be used");
}

WebProxy ^ myProxy = gcnew WebProxy;

Console::WriteLine("\nPlease enter the new Proxy Address that is to be set:");
Console::WriteLine("(Example:http://myproxy.example.com:port)");
String ^ proxyAddress;

try 
{
    proxyAddress = Console::ReadLine();
    if (proxyAddress->Length > 0) {
        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 newUri object to 'myProxy' object so that new myProxy settings can be set.
        myProxy->Address = newUri;
        // Create a NetworkCredential object and associate it with the Proxy property of request object.
        myProxy->Credentials =
            gcnew NetworkCredential(username, password);
        myWebRequest->Proxy = myProxy;
    }
    Console::WriteLine("\nThe Address of the  new Proxy settings are {0}",
                  myProxy->Address);
    HttpWebResponse ^ myWebResponse =
        (HttpWebResponse ^) (myWebRequest->GetResponse());

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

// Obtain the 'Proxy' of the  Default browser.
IWebProxy proxy = myWebRequest.Proxy;
// Print the Proxy Url to the console.
if (proxy != null)
{
    Console.WriteLine("Proxy: {0}", proxy.GetProxy(myWebRequest.RequestUri));
}
else
{
    Console.WriteLine("Proxy is null; no proxy will be used");
}

WebProxy myProxy=new WebProxy();

Console.WriteLine("\nPlease enter the new Proxy Address that is to be set:");
Console.WriteLine("(Example:http://myproxy.example.com:port)");
string proxyAddress;

try
{
    proxyAddress =Console.ReadLine();
    if(proxyAddress.Length>0)
    {
        Console.WriteLine("\nPlease enter the Credentials (may not be needed)");
        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 newUri object to 'myProxy' object so that new myProxy settings can be set.
        myProxy.Address=newUri;
        // Create a NetworkCredential object and associate it with the
        // Proxy property of request object.
        myProxy.Credentials=new NetworkCredential(username,password);
        myWebRequest.Proxy=myProxy;
    }
    Console.WriteLine("\nThe Address of the  new Proxy settings are {0}",myProxy.Address);
    HttpWebResponse myWebResponse=(HttpWebResponse)myWebRequest.GetResponse();

' Create a new request to the mentioned URL.				
Dim myWebRequest As HttpWebRequest = CType(WebRequest.Create("http://www.microsoft.com"), HttpWebRequest)

      ' Obtain the 'Proxy' of the  Default browser.  
      Dim proxy as IWebProxy = CType(myWebRequest.Proxy, IWebProxy)
      ' Print the Proxy Url to the console.
If Not proxy Is Nothing Then
    Console.WriteLine("Proxy: {0}", proxy.GetProxy(myWebRequest.RequestUri))
Else
    Console.WriteLine("Proxy is null; no proxy will be used")
End If

Dim myProxy As New WebProxy()

Console.WriteLine(ControlChars.Cr + "Please enter the new Proxy Address that is to be set ")
Console.WriteLine("(Example:http://myproxy.example.com:port)")
Dim proxyAddress As String
Try
    proxyAddress = Console.ReadLine()
    If proxyAddress.Length = 0 Then
        myWebRequest.Proxy = myProxy
    Else
        Console.WriteLine(ControlChars.Cr + "Please enter the Credentials (may not be needed)")
        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 newUri object to 'myProxy' object so that new myProxy settings can be set.
        myProxy.Address = newUri
        ' Create a NetworkCredential object and associate it with the Proxy property of request 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 HttpWebResponse = CType(myWebRequest.GetResponse(), HttpWebResponse)

注解

Proxy 属性标识用于处理对 Internet 资源的请求的 WebProxy 对象。 若要指定不应使用代理，请将 Proxy 属性设置为 GlobalProxySelection.GetEmptyWebProxy 方法返回的代理实例。

本地计算机或应用程序配置文件可以指定使用默认代理。 如果指定了 Proxy 属性，则 属性中的代理设置 Proxy 将替代本地计算机或应用程序配置文件， HttpWebRequest 并且实例将使用指定的代理设置。 如果未在配置文件中指定代理， Proxy 并且未指定 属性，则 HttpWebRequest 类将使用从本地计算机上的 Internet Explorer 继承的代理设置。 如果 Internet Explorer 中没有代理设置，则请求将直接发送到服务器。

类 HttpWebRequest 使用从 Internet Explorer 继承的通配符分析代理绕过列表，这与 Internet Explorer 直接分析绕过列表相同。 例如， HttpWebRequest 类将 Internet Explorer 中的“nt*”旁路列表分析为“nt.*”的正则表达式。 因此，“”http://nt.com的 URL 将使用 类和 Internet Explorer 绕过代理 HttpWebRequest 。

HttpWebRequest 类支持本地代理绕过。 如果满足以下任一条件，该类会将目标视为本地目标：

  • 目标包含平面名称（URL 中不含点）。

  • 目标包含环回地址（Loopback 或 IPv6Loopback），或者目标包含分配给本地计算机的 IPAddress。

  • 目标的域后缀匹配本地计算机的域后缀 (DomainName)。

在通过调用 、、 或 方法启动请求后更改 Proxy 属性会InvalidOperationException引发 。BeginGetResponseGetResponseBeginGetRequestStreamGetRequestStream 有关代理元素的信息，请参阅 <defaultProxy>元素 (网络设置) 。

适用于

另请参阅