完成网络请求后显示启动屏幕并隐藏答案

【问题标题】：Show splash screen and hide after finish web request完成网络请求后显示启动屏幕并隐藏
【发布时间】：2012-04-19 19:12:42
【问题描述】：

当我的应用启动时，我想显示启动画面并创建 httpwebrequest，当请求完成时，隐藏启动画面并显示主页。

这是我的启动画面：

    private void ShowPopup()
    {
        this.popup = new Popup();
        this.popup.Child = new PopupSplash();
        this.popup.IsOpen = true;
        StartLoadingData();
    }

    private void StartLoadingData()
    {
        backgroundWorker = new BackgroundWorker();
        backgroundWorker.DoWork += new DoWorkEventHandler(backgroundWorker_DoWork);
        backgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker_RunWorkerCompleted);
        backgroundWorker.RunWorkerAsync();
    }

    void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        this.Dispatcher.BeginInvoke(() =>
            {
                this.popup.IsOpen = false;
            }
        );
    }

    void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
    {

        using (var db = new ListDataContext(ListDataContext.DBConnectionString))
        {
            if (!db.DatabaseExists())
            {
                db.CreateDatabase();
            }
        }
        Thread.Sleep(4000);
    }

这是我的 httpwebrequest：

    private void main_WebResponseAvailableEventHandler(object sender, string response, string url)
    {
            SearchResult result = new SearchResult(response, url);

            PhoneApplicationService.Current.State["result"] = result;
            this.NavigationService.Navigate(new Uri("/SearchPivotPage.xaml", UriKind.Relative));
    }

    private void HandleWebResponse(IAsyncResult asyncResult)
    {
        WebRequestState state = (WebRequestState)asyncResult.AsyncState;
        HttpWebRequest request = state.Request;
        string url = request.RequestUri.ToString();
        state.Response = (HttpWebResponse)request.EndGetResponse(asyncResult);

        if (state.Response != null)
        {
            StreamReader reader = new StreamReader(state.Response.GetResponseStream());
            StringBuilder sb = new StringBuilder();
            while (!reader.EndOfStream)
                sb.Append(reader.ReadLine());
            string text = sb.ToString();
            Dispatcher.BeginInvoke(() =>
            {
                if (WebResponseAvailable != null)
                {
                    WebResponseAvailable(this, text, url);
                }
            });
        }
    }

在构造函数MainPage()中

        ....
        ShowPopup();
        HttpWebRequest movieRequest = (HttpWebRequest)WebRequest.Create(url);
        WebRequestState state = new WebRequestState();
        state.Request = movieRequest;
        movieRequest.BeginGetResponse(new AsyncCallback(HandleWebResponse), state);
        WebResponseAvailable += main_WebResponseAvailableEventHandler;
        ....

有没有办法我可以做我想做的事？或者两者都在其他线程中这是不可能的？

【问题讨论】：

标签： multithreading httpwebrequest windows-phone-7.1 splash-screen

【解决方案1】：

您可以通过添加一个新的SplashScreenPage.xaml 页面而不是SpalshScreen.jpg 文件来创建一个假的splashScreen。如果您删除 SplashScreen.jpg 文件，则应该加载的第一页（来自 App.xaml）将是 SplashScreenPage.xaml，您可以在那里执行任何操作，如您在上面指出的 webrequest。一旦 webrequest 结束，然后导航到 mainPage.xaml，然后调用 RemoveBackEntry 方法以使 MainPage.xaml 成为 BackStack 中的第一个页面条目。

问候，

【讨论】：