C# Windows Phone保留页面状态不工作

当我转到另一个页面时，我试图保留页面状态，但由于某些原因，当我返回到此页面时，这些项目将返回到其默认状态。为什么不起作用？它似乎完全遵循教程

        protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
    {
        base.OnNavigatedFrom(e);


        State["Title"] = TitleTextBox.Text;

        //all of those are RadioButtons - if their is a better way to do it then please comment :)
        int i = new int();
        if (RB0.IsChecked.Value)
            i = 0;
        else if (RB1.IsChecked.Value)
            i = 1;
        else if (RB2.IsChecked.Value)
            i = 2;
        else if (RB3.IsChecked.Value)
            i = 3;
        State["CheckedRB"] = i;

    }

    protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
    {
        base.OnNavigatedTo(e);

        if (State.ContainsKey("Title"))
            TitleTextBox.Text = State["Title"] as string;
        if (State.ContainsKey("CheckedRB"))
        {
            int i = (int)State["CheckedRB"];

            if (i == 0)
                RB0.IsChecked = true;
            else if (i == 1)
                RB1.IsChecked = true;
            else if (i == 2)
                RB2.IsChecked = true;
            else if (i == 3)
                RB3.IsChecked = true;
        }
     }

编辑：我通过添加断点来跟踪问题

            protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
    {
        base.OnNavigatedFrom(e);


        State["Title"] = TitleTextBox.Text;
        string look0 = WorkOutName.Text; 
        string look = State["WorkOutName"] as string; 

        int i = new int();
        if (RB0.IsChecked.Value)
            i = 0;
        else if (RB1.IsChecked.Value)
            i = 1;
        else if (RB2.IsChecked.Value)
            i = 2;
        else if (RB3.IsChecked.Value)
            i = 3;
        State["CheckedRB"] = i;   <-------- breakpoint

与OnNavigatedTo相同：

    protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
    {
        base.OnNavigatedTo(e);

        if (State.ContainsKey("Title"))
            TitleTextBox.Text = State["Title"] as string; <--breakpoint
        if (State.ContainsKey("CheckedRB"))
        {
            int i = (int)State["CheckedRB"]; <--breakpoint

            if (i == 0)
                RB0.IsChecked = true;
            else if (i == 1)
                RB1.IsChecked = true;
            else if (i == 2)
                RB2.IsChecked = true;
            else if (i == 3)
                RB3.IsChecked = true;
        }
     }

受保护的覆盖无效OnNavigatedTo（System.Windows.Navigation.NavigationEventArgs e）
{
基地。导航到（e）；
如果（注明集装箱（“名称”））
TitleTextBox.Text=State[“Title”]as string；我尝试了你的代码，它似乎工作正常。我不知道这是否是你的情况，但请记住，如果你在应用程序中有以下导航流：

Page1 (forward navigation)-> Page2 (back navigation)-> Page1 (forward navigation)-> Page2

如果您在第一次访问第2页时将状态保存在该页中，则在再次返回第2页时将不会保留该状态，这是因为在执行反向导航时，该页将被丢弃，该页的状态字典也将被丢弃。您可以在

Page1 (forward navigation)-> Page2 (back navigation)-> Page1 (forward navigation)-> Page2