Question

我是WP8开发的新手，我正在创建一个具有WebBrowserControl的应用程序来访问我的网站。我想在应用程序到达后台时保存WebBrowser的状态，但我不能这样做（即当用户想要重新打开应用程序时，WebBrowser将加载最后一页看到的内容）。我的代码based in this如下：

WebBrowser属性：Base和Source为空。

App.xaml.cs ：

public partial class App : Application
{
    //Url to store current address to maintain state when application is in background
    public Uri Url { get; set; }
    //Boolean to get if phone has been previously in background
    public Boolean firstRun = true;

    private void Application_Activated(object sender, ActivatedEventArgs e)
    {
        IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
        Uri currentUrl;
        if (settings.TryGetValue("Url", out currentUrl))
            Url = (Uri)settings["Url"];
    }

    private void Application_Deactivated(object sender, DeactivatedEventArgs e)
    {
        IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
        settings["Url"] = Url;
        firstRun = false;
        settings.Save();
    }

MainPage.xaml.cs ：

public partial class MainPage : PhoneApplicationPage
 {
    Uri baseUrl = new Uri("http://my_url");

    // Constructor
    public MainPage()
    {
        InitializeComponent();
        webBrowser.Navigated += new EventHandler<NavigationEventArgs>(WebBrowserNavigation);
        App app = Application.Current as App;
        if (app.firstRun)
        {
            webBrowser.Navigate(baseUrl);
        }
    }

    async void WebBrowserNavigation(Object sender, NavigationEventArgs navArgs)
    {
        string url = navArgs.Uri.ToString();
        App app = Application.Current as App;
        app.Url = navArgs.Uri;
    }

Answer 1

我认为你让bring it to the foreground和relaunching感到困惑。要将其恢复到前台，请在按下Windows按钮后按后退按钮。您将看到您的应用程序正是您离开它的位置。如果您通过按标题或使用开始菜单重新启动程序，它将启动它的新实例...从而显示您的基本URL。

所以基本上FirstRun在你的程序中并不重要。启动程序时，您应该通过执行此操作获取最后一个URL

private void Application_Launching(object sender, LaunchingEventArgs e)
{
    // this.FirstRun = true; // doesn't matter

    IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
    Uri currentUrl;
    if (settings.TryGetValue("Url", out currentUrl))
    {
        Url = (Uri)settings["Url"];            // got the last url
    }
    else
    {
        Url = new Uri(@"http://www.msn.com");  // last url not defined, set it to default base
    }
}

在两个活动中保存您的上一个网址

// Code to execute when the application is deactivated (sent to background)
// This code will not execute when the application is closing
private void Application_Deactivated(object sender, DeactivatedEventArgs e)
{
    IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
    settings["Url"] = Url;
    settings.Save();
}

// Code to execute when the application is closing (eg, user hit Back)
// This code will not execute when the application is deactivated
private void Application_Closing(object sender, ClosingEventArgs e)
{
    IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
    settings["Url"] = Url;
    settings.Save();
}

当您的MainPage加载后，导航到保存的URL

public MainPage()
{
    InitializeComponent();

    App myApp = Application.Current as App;

    webBrowser.Navigated += new EventHandler<NavigationEventArgs>(WebBrowserNavigation);

    webBrowser.Navigate(myApp.Url);
}

这样做，它总是保存您的状态，如果您将它带到前台或从标题或开始菜单再次启动它并不重要。您可以说，此时您正好tomestoned了您的WebBrowser网址。

保留WebBrowser控件状态

1 个答案: