HttpWebRequest.Proxy 属性
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
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, setPublic Overrides Property Proxy As IWebProxy属性值
用于代理请求的 IWebProxy 对象。 通过调用 Select 属性来设置默认值。
例外
Proxy 设置为 null。
请求是通过调用 GetRequestStream()、BeginGetRequestStream(AsyncCallback, Object)、GetResponse()或 BeginGetResponse(AsyncCallback, Object)启动的。
调用方没有请求的操作的权限。
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
谨慎
WebRequest、HttpWebRequest、ServicePoint和 WebClient 已过时，不应将其用于新开发。 请改用 HttpClient。
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 Proxy 属性中的代理设置将覆盖本地计算机或应用程序配置文件，HttpWebRequest 实例将使用指定的代理设置。 如果在配置文件中未指定代理，并且未指定 Proxy 属性，HttpWebRequest 类将使用从本地计算机上的 Internet 选项继承的代理设置。 如果 Internet 选项中没有代理设置，则请求将直接发送到服务器。
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：
目标包含平面名称（URL 中没有点）。
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。
目标的域后缀与本地计算机的域后缀（DomainName）匹配。
通过调用 GetRequestStream、BeginGetRequestStream、GetResponse或 BeginGetResponse 方法启动请求后更改 Proxy 属性将引发 InvalidOperationException。 有关代理元素的信息，请参阅 <defaultProxy>元素（网络设置）。
