Silverlight HttpWebRequest SecurityException

时间:2011-11-28 18:20:34

标签: c# silverlight web-applications silverlight-4.0 httpwebrequest

问题

我有一个在远程服务器上运行的restful Web服务。我已经制作了一个使用它的WP7应用程序,所以我知道它有效。我正在将应用程序移植到Silverlight Web应用程序并遇到问题。

我已经包含了代码的简化版本以及引发的错误。 EndGetResponse方法会引发错误。

随时询问更多信息。我一直在寻找解决方案,但没有发现任何有效或真正适用于我的问题的东西。看起来像这样简单的代码,它在WP7版本上运行得很好。任何帮助将不胜感激。

代码

void SendRequest() {
    string url = "http://some-example-restful-service:5600/locations/data/all";
    HttpWebRequest request = (HttpWebRequest) HttpWebRequest.Create(url);

    request.Method = "POST";
    request.ContentType = "application/json; charset=utf-8";

    request.BeginGetResponse(new AsyncCallback(RequestCallback), request);
}

public static void RequestCallback(IAsyncResult asyncResult) {
    HttpWebRequest request = (HttpWebRequest) asyncResult.AsyncState;
    HttpWebResponse response = (HttpWebResponse) request.EndGetResponse(asyncResult);

    //Parse JSON object

    response.Close();

    //Dispatch result back to GUI thread
}

错误

SecurityException未被用户代码

处理

System.Security.SecurityException:安全错误。

at System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.<EndGetResponse>b__4(Object sendState)
at System.Net.Browser.AsyncHelper.<>c__DisplayClass4.<BeginOnUI>b__0(Object sendState)
--- End of inner exception stack trace ---
at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
at System.Net.Browser.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at ServieTest.MainPage.RequestCallback(IAsyncResult asyncResult)
at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClassd.<InvokeGetResponseCallback>b__b(Object state2)
at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()

2 个答案:

答案 0 :(得分:7)

原来我需要在服务域的根目录中添加clientaccesspolicy.xml文件。

以下是文件的内容:

<?xml version="1.0" encoding="utf-8"?>
<access-policy>
    <cross-domain-access>
        <policy>
            <allow-from http-request-headers="*">
                <domain uri="*"/>
            </allow-from>
            <grant-to>
                <resource path="/" include-subpaths="true"/>
            </grant-to>
        </policy>
    </cross-domain-access>
</access-policy> 

答案 1 :(得分:1)

根据this answer,Silverlight(浏览器内)尊重您请求数据的服务器的cross-domain policy。由于它是您自己的Web服务,因此您可以将crossdomain.xml文件添加到应用程序的根目录,以允许外部域发出跨域请求(this answer)。