C# 如何使用Silverlight GET HttpWebRequest设置标题？

使用HttpWebRequest向Silverlight中的RESTful服务发出请求，只要不向请求添加任何头，就可以正常工作

只要我用这样的代码添加一个头

var webReq = (HttpWebRequest)WebRequest.Create(new Uri(_RemoteAddress, "GetProviderMetadata"));
webReq.Method = HttpMethodType.Get;
webReq.Headers["SomeToken"] = "someTokenValue";

只要调用

EndGetResponse（）

，我就会在这个问题的底部粘贴异常。有人知道这是为什么吗？在普通的.NET中，添加头来获取请求似乎工作得很好，所以我猜这是Silverlight的某种限制，但我找不到任何文档来澄清这一点

   {System.NotSupportedException ---> System.NotSupportedException: Specified method is not supported.
  at System.Net.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
  at System.Net.BrowserHttpWebRequest.<>c__DisplayClass5.<EndGetResponse>b__4(Object sendState)
  at System.Net.AsyncHelper.<>c__DisplayClass2.<BeginOnUI>b__0(Object sendState)
  --- End of inner exception stack trace ---
  at System.Net.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
  at System.Net.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
  at System.Net.BrowserHttpWebRequest.<>c__DisplayClassd.<InvokeGetResponseCallback>b__b(Object state2)
  at System.Threading._ThreadPoolWaitCallback.WaitCallback_Context(Object state)
  at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
  at System.Threading._ThreadPoolWaitCallback.PerformWaitCallbackInternal(_ThreadPoolWaitCallback tpWaitCallBack)
  at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback(Object state)}
   [System.NotSupportedException]: {System.NotSupportedException ---> System.NotSupportedException: Specified method is not supported.
  at System.Net.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
  at System.Net.BrowserHttpWebRequest.<>c__DisplayClass5.<EndGetResponse>b__4(Object sendState)
  at System.Net.AsyncHelper.<>c__DisplayClass2.<BeginOnUI>b__0(Object sendState)
  --- End of inner exception stack trace ---
  at System.Net.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
  at System.Net.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
  at System.Net.BrowserHttpWebRequest.<>c__DisplayClassd.<InvokeGetResponseCallback>b__b(Object state2)
  at System.Threading._ThreadPoolWaitCallback.WaitCallback_Context(Object state)
  at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
  at System.Threading._ThreadPoolWaitCallback.PerformWaitCallbackInternal(_ThreadPoolWaitCallback tpWaitCallBack)
  at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback(Object state)}
   _className: "System.NotSupportedException"
   _data: {System.Collections.ListDictionaryInternal}
   _dynamicMethods: null
   _exceptionMethod: null
   _exceptionMethodString: null
   _helpURL: null
   _HResult: -2146233067
   _innerException: {System.NotSupportedException: Specified method is not supported.
  at System.Net.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
  at System.Net.BrowserHttpWebRequest.<>c__DisplayClass5.<EndGetResponse>b__4(Object sendState)
  at System.Net.AsyncHelper.<>c__DisplayClass2.<BeginOnUI>b__0(Object sendState)}
   _message: ""
   _remoteStackIndex: 0
   _remoteStackTraceString: null
   _source: "System.Windows"
   _stackTrace: {sbyte[192]}
   _stackTraceString: null
   _xcode: -532462766
   _xptrs: 0
   Data: {System.Collections.ListDictionaryInternal}
   HelpLink: null
   HResult: -2146233067
   InnerException: {System.NotSupportedException: Specified method is not supported.
  at System.Net.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
  at System.Net.BrowserHttpWebRequest.<>c__DisplayClass5.<EndGetResponse>b__4(Object sendState)
  at System.Net.AsyncHelper.<>c__DisplayClass2.<BeginOnUI>b__0(Object sendState)}
   Message: ""
   Source: "System.Windows"
   StackTrace: "   at System.Net.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)\r\n   at System.Net.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)\r\n   at Intellidimension.RdfEntity.Service.RemoteEntityServiceProviderClient.getProviderMetadataResponse(IAsyncResult result)\r\n   at System.Net.BrowserHttpWebRequest.<>c__DisplayClassd.<InvokeGetResponseCallback>b__b(Object state2)\r\n   at System.Threading._ThreadPoolWaitCallback.WaitCallback_Context(Object state)\r\n   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)\r\n   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallbackInternal(_ThreadPoolWaitCallback tpWaitCallBack)\r\n   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback(Object state)"
   System.Runtime.InteropServices._Exception.HelpLink: null
   System.Runtime.InteropServices._Exception.Source: "System.Windows"

{System.NotSupportedException-->System.NotSupportedException:不支持指定的方法。
在System.Net.BrowserHttpWebRequest.InternalEndGetResponse（IAsyncResult asyncResult）上
在System.Net.BrowserHttpWebRequest.c__DisplayClass5.b__4（对象发送状态）中
在System.Net.AsyncHelper.c__DisplayClass2.b__0（对象发送状态）中
---内部异常堆栈跟踪的结束---
位于System.Net.AsyncHelper.BeginOnUI（SendOrPostCallback beginMethod，对象状态）
位于System.Net.BrowserHttpWebRequest.EndGetResponse（IAsyncResult asyncResult）
在System.Net.BrowserHttpWebRequest.c__DisplayClassd.b__b（对象状态2）中
在System.Threading._ThreadPoolWaitCallback.WaitCallback_上下文（对象状态）
在System.Threading.ExecutionContext.Run（ExecutionContext ExecutionContext，ContextCallback回调，对象状态）
在System.Threading.\u ThreadPoolWaitCallback.PerformWaitCallbackInternal（\u ThreadPoolWaitCallback tpWaitCallBack）
在System.Threading.\u ThreadPoolWaitCallback.PerformWaitCallback（对象状态）}
[System.NotSupportedException]：{System.NotSupportedException-->System.NotSupportedException:不支持指定的方法。
在System.Net.BrowserHttpWebRequest.InternalEndGetResponse（IAsyncResult asyncResult）上
在System.Net.BrowserHttpWebRequest.c__DisplayClass5.b__4（对象发送状态）中
在System.Net.AsyncHelper.c__DisplayClass2.b__0（对象发送状态）中
---内部异常堆栈跟踪的结束---
位于System.Net.AsyncHelper.BeginOnUI（SendOrPostCallback beginMethod，对象状态）
位于System.Net.BrowserHttpWebRequest.EndGetResponse（IAsyncResult asyncResult）
在System.Net.BrowserHttpWebRequest.c__DisplayClassd.b__b（对象状态2）中
在System.Threading._ThreadPoolWaitCallback.WaitCallback_上下文（对象状态）
在System.Threading.ExecutionContext.Run（ExecutionContext ExecutionContext，ContextCallback回调，对象状态）
在System.Threading.\u ThreadPoolWaitCallback.PerformWaitCallbackInternal（\u ThreadPoolWaitCallback tpWaitCallBack）
在System.Threading.\u ThreadPoolWaitCallback.PerformWaitCallback（对象状态）}
_类名：“System.NotSupportedException”
_数据：{System.Collections.ListDictionaryInternal}
_dynamicMethods:null
_例外方法：null
_exceptionMethodString:null
_帮助URL:null
_HResult:-2146233067
_innerException:{System.NotSupportedException:不支持指定的方法。
在System.Net.BrowserHttpWebRequest.InternalEndGetResponse（IAsyncResult asyncResult）上
在System.Net.BrowserHttpWebRequest.c__DisplayClass5.b__4（对象发送状态）中
在System.Net.AsyncHelper.c__DisplayClass2.b__0（对象发送状态）}
_信息：“
_remoteStackIndex:0
_remoteStackTraceString:空
_资料来源：“System.Windows”
_堆栈跟踪：{sbyte[192]}
_stackTraceString:空
_xcode:-532462766
_xptrs:0
数据：{System.Collections.ListDictionaryInternal}
帮助链接：空
HResult:-2146233067
InnerException:{System.NotSupportedException:不支持指定的方法。
在System.Net.BrowserHttpWebRequest.InternalEndGetResponse（IAsyncResult asyncResult）上
在System.Net.BrowserHttpWebRequest.c__DisplayClass5.b__4（对象发送状态）中
在System.Net.AsyncHelper.c__DisplayClass2.b__0（对象发送状态）}
信息：“
资料来源：“System.Windows”
StackTrace:“位于System.Net.AsyncHelper.BeginUnui（SendOrPostCallback beginMethod，对象状态）\r\n位于System.Net.BrowserHttpWebRequest.EndGetResponse（IAsyncResult asyncResult）\r\n位于Intellidimension.RdfEntity.Service.RemoteEntityServiceProviderClient.getProviderMetadataResponse（IAsyncResult结果）\r\n在System.Net.BrowserHttpWebRequest.c_uuDisplayClassd.b_uub（对象状态2）\r\n在System.Threading.\u ThreadPoolWaitCallback.WaitCallback\u Context（对象状态）\r\n在System.Threading.ExecutionContext.Run（ExecutionContext ExecutionContext，ContextCallback callback，对象状态）\r\n在System.Threading.\u ThreadPoolWaitCallback.PerformWaitCallbackInternal（\u ThreadPoolWaitCallback tpWaitCallBack）\r\n在System.Threading.\u ThreadPoolWaitCallback.PerformWaitCallback（对象状态）
System.Runtime.InteropServices.\u Exception.HelpLink:null
System.Runtime.InteropServices.\u Exception.Source:“System.Windows”

Silverlight仅支持使用POST方法而不是GET方法设置标题。这是由于在Silverlight中实现TCP/IP堆栈的方式受到限制。它使用浏览器扩展API，而不是直接与主机操作系统的API对抗。

在调用之前指定，然后启动WebRequest

像这样：

bool httpResult = WebRequest.RegisterPrefix("http://", WebRequestCreator.ClientHttp);
bool httpsResult = WebRequest.RegisterPrefix("https://", WebRequestCreator.ClientHttp);

---

我猜可能是这样的。您是否有解释此限制的MSDN文档链接？我找不到任何内容。我能找到的最接近的内容是本页底部的列表：某些标题根据方法和URI受到限制。我已验证使用ClientHttp允许在GET请求上设置标题，尽管我将每个WebRequest创建为ClientHttp，如下所示：

var request=（HttpWebRequest）System.Net.Browser.WebRequestCreator.ClientHttp.Create（端点）

BrowserHttp限制GET请求的头（如前面的回答所述），但ClientHttp不限制。