Question

我在WP7应用程序中遇到基本的HttpWebRequest问题。一旦我调用BeginGetRequestStream，它就会出错。然后，回调方法会收到IAsyncResult，但没有AsyncWaitHandle。

AsyncWaitHandle ='ar.AsyncWaitHandle'抛出了'System.NotSupportedException'类型的异常

我在下面创建了一个产生错误的示例。为了创建这个，我刚刚采用了示例数据透视应用程序，并试图将一些数据发布到MainViewModel的构造函数中的服务器上。

   public MainViewModel()
    {
        this.Items = new ObservableCollection<ItemViewModel>();

        HttpWebRequest webRequest = WebRequest.CreateHttp("http://www.google.co.uk");

        webRequest.Method = "POST";
        webRequest.ContentType = "application/x-www-form-urlencoded";

        webRequest.BeginGetRequestStream(BeginGetRequestStreamCallBack, webRequest);
    }

    private void BeginGetRequestStreamCallBack(IAsyncResult ar)
    {
        HttpWebRequest webRequest = (HttpWebRequest) ar.AsyncState;

        Stream requestStream = webRequest.EndGetRequestStream(ar);

        using(StreamWriter sw = new StreamWriter(requestStream))
        {
            sw.Write("{ test: \"test\" }");
        }

        webRequest.BeginGetResponse(BeginGetResponseCallback, webRequest);
    }

    private void BeginGetResponseCallback(IAsyncResult ar)
    {
        HttpWebRequest webRequest = (HttpWebRequest)ar.AsyncState;

        WebResponse webResponse = webRequest.EndGetResponse(ar);

        Stream responseStream = webResponse.GetResponseStream();

        string whatCameBack = new StreamReader(responseStream).ReadToEnd();
    }

任何帮助都将一如既往，非常感谢。

我已经深入研究了这一点，我似乎无法使用BeginGetRequestStream发布数据。

    public MainViewModel()
    {
        this.Items = new ObservableCollection<ItemViewModel>();

        HttpWebRequest webRequest = WebRequest.CreateHttp("http://www.google.co.uk");

        //webRequest.Method = "POST";
        //webRequest.ContentType = "application/x-www-form-urlencoded";

        //webRequest.BeginGetRequestStream(BeginGetRequestStreamCallBack, webRequest);
        webRequest.BeginGetResponse(BeginGetResponseCallback, webRequest);
    }

    private void BeginGetRequestStreamCallBack(IAsyncResult ar)
    {
        HttpWebRequest webRequest = (HttpWebRequest) ar.AsyncState;

        Stream requestStream = webRequest.EndGetRequestStream(ar);

        using(StreamWriter sw = new StreamWriter(requestStream))
        {
            sw.Write("{ test: \"test\" }");
        }

        webRequest.BeginGetResponse(BeginGetResponseCallback, webRequest);
    }

    private void BeginGetResponseCallback(IAsyncResult ar)
    {
        HttpWebRequest webRequest = (HttpWebRequest)ar.AsyncState;

        WebResponse webResponse = webRequest.EndGetResponse(ar);

        Stream responseStream = webResponse.GetResponseStream();

        string whatCameBack = new StreamReader(responseStream).ReadToEnd();
    }

这没关系，但这不是我想要的。

有什么想法吗？

Answer 1

我是一个顽皮的男孩，而不是正确关闭流。

using(Stream requestStream = webRequest.EndGetRequestStream(ar))
{}

一切都很好。

Wp7上的HttpWebRequest AsyncWaitHandle有System.NotSupportedException

1 个答案: