C# 如何从回调函数wp7获取响应值

我正在使用WindowsPhone7。如何从以下代码中获取响应值

private void sampleRequest()
{
    try
    {
        HttpWebRequest httpLoginRequest = (HttpWebRequest)WebRequest.Create(new Uri(DisplayMessage.Authentication_URL ));
        httpLoginRequest.Method = DisplayMessage.Get_Method;
        Parameters = new Dictionary<string, string>();
        httpLoginRequest.BeginGetResponse(new AsyncCallback(GetLoginCallback), httpLoginRequest);
    }
    catch (Exception ex)
    {
        throw ex;
    }
}

private void GetLoginCallback(IAsyncResult asynchronousResult)
{
    try
    {
        HttpWebRequest httpRequest = (HttpWebRequest)asynchronousResult.AsyncState;
        HttpWebResponse httpresponse = (HttpWebResponse)httpRequest.EndGetResponse(asynchronousResult);
    }
    catch(WebException ex)
    {

    }
}

SampleRequest被放置在不同的类中，例如classA。现在我需要类B中的httpresponse值。任何人都可以帮助我实现这一目标

---

提前感谢

有几种方法可以做到这一点：

-第一种方法是使用Microsoft.Bcl.Async nuget软件包，该软件包使您能够在windows phone 7应用程序中使用Async/await，并使您能够通过等待sampleRequest来获取返回值，方法与在非异步情况下执行sampleRequest类似：

    private async Task<WebResponse> sampleRequest()
    {
        try
        {
            HttpWebRequest httpLoginRequest = (HttpWebRequest)WebRequest.Create(new Uri(DisplayMessage.Authentication_URL));
            httpLoginRequest.Method = DisplayMessage.Get_Method;
            Parameters = new Dictionary<string, string>();
            WebResponse webResponse =await httpLoginRequest.GetResponseAsync();
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

-第二种方法是将自己的回调作为sampleRequest的参数传递：

    public class State
    {
        public HttpWebRequest WebRequest { get; set; }
        public Action<HttpWebResponse > ResponseCallBack;
    }

    void sampleRequest(Action<HttpWebResponse > responseCallBack)
    {
        HttpWebRequest httpLoginRequest = (HttpWebRequest)WebRequest.Create(new Uri(DisplayMessage.Authentication_URL));
        //httpLoginRequest.Method = DisplayMessage.Get_Method;
        //Parameters = new Dictionary<string, string>();
        httpLoginRequest.BeginGetResponse(new AsyncCallback(GetLoginCallback), 
            new State(){WebRequest = httpLoginRequest,
                        ResponseCallBack = responseCallBack
            });
    }



    private void GetLoginCallback(IAsyncResult asynchronousResult)
    {
        try
        {
            State state= (State)asynchronousResult.AsyncState;
            HttpWebResponse httpresponse = (HttpWebResponse)state.WebRequest.EndGetResponse(asynchronousResult);
              ...

             //Dispatch request back to ui thread
              Deployment.Current.Dispatcher.BeginInvoke(() =>
              {
                   state.ResponseCallBack(httpresponse );
               });
        }
        catch(WebException ex)
        {

        }
    }

-第三种方法是只在classA上添加一个事件，您将在tGetLoginCallback中触发该事件，并在classB中注册该事件：

   public event EventHandler<Response> LoginComplete;


   void sampleRequest(){
      //identical original one
      ....
    }


    private void GetLoginCallback(IAsyncResult asynchronousResult)
    {
        try
        {
            HttpWebRequest httpRequest = (HttpWebRequest)asynchronousResult.AsyncState;
            HttpWebResponse httpresponse = (HttpWebResponse)httpRequest.EndGetResponse(asynchronousResult);

            ...

              //Dispatch request back to ui thread
              Deployment.Current.Dispatcher.BeginInvoke(() =>
              {
                   if (LoginComplete != null)
                   {
                        LoginComplete(this,response);
                   }
               });

        }
        catch (WebException ex)
        {

        }
    }

---

你试过什么吗。你可以尝试将响应公开，并在类b中声明类A，这样你就可以访问那里的响应。如果我也公开，我就不会得到值。。。因为它是一个回调函数，它将单独运行……哦，我明白了，我之前错过了：你能告诉我你在哪里声明了myresponse吗。在第二种方式中，我只是一个占位符，用于传递回类B的任何内容，一般来说，它只是一个类的实例，在这个实例中，您将提取任何您想要返回的数据。在我的示例中，这个类称为Response，它是我在State中使用的。例如，在登录的情况下，OAuth令牌maybe？in func响应不可用，请求namespace.ya对。。。所以，只有我试图通过httpresponse，但它说func不需要1个参数。用httpresponse更新了我的答案，而且需要使用的是Action而不是func

classAInstance.sampleRequest((httpResponse)=>{
   //Do what you want with http response here
});

   public event EventHandler<Response> LoginComplete;


   void sampleRequest(){
      //identical original one
      ....
    }


    private void GetLoginCallback(IAsyncResult asynchronousResult)
    {
        try
        {
            HttpWebRequest httpRequest = (HttpWebRequest)asynchronousResult.AsyncState;
            HttpWebResponse httpresponse = (HttpWebResponse)httpRequest.EndGetResponse(asynchronousResult);

            ...

              //Dispatch request back to ui thread
              Deployment.Current.Dispatcher.BeginInvoke(() =>
              {
                   if (LoginComplete != null)
                   {
                        LoginComplete(this,response);
                   }
               });

        }
        catch (WebException ex)
        {

        }
    }