WP8应用栏被隐藏后要做的事情

Question

I'm in the process of implementing my own popup menu for app bar icon buttons (something similar to the PhoneFlipMenu tool). I'm using a vertical StackPanel for my popup, and I need to display it with animation when the corresponding app bar button is clicked. The code looks like this:

private void appBarIconButtonList_Click(object sender, EventArgs e)
{
    ApplicationBar.IsVisible = false;
    AnimatePopupMenuListCommands(true);
}

private void AnimatePopupMenuListCommands(bool openMenu)
{
    PlaneProjection planeProjection = popupMenuListCommands.Projection as PlaneProjection;

    DoubleAnimation anima = new DoubleAnimation();
    if (openMenu)
    {
        anima.From = 90;
        anima.To = 0;
    }
    else
    {
        anima.From = 0;
        anima.To = 90;
    }
    anima.Duration = new Duration(TimeSpan.FromSeconds(0.1));

    Storyboard.SetTarget(anima, planeProjection);
    Storyboard.SetTargetProperty(anima, new PropertyPath(PlaneProjection.RotationXProperty));

    Storyboard storyboard = new Storyboard();
    storyboard.Children.Add(anima);
    storyboard.Begin();
}

The main problem is that the animation begins before the application bar is hidden. As a result, the popup menu jumps a little bit after that. How to run the animation after the application bar has been totally hidden?

Answer 1

Try to hide application bar after the animation is complete.

 storyboard.Completed += storyboard_Completed;


    void storyboard_Completed(object sender, EventArgs e)
    {
        ApplicationBar.IsVisible = false;
    }

Answer 2

You could wait for the appbar to be hidden using the Dispatcher or a DispatcherTimer. Here is an exmaple using the Dispatcher:

private void ApplicationBarIconButton_OnClick(object sender, EventArgs e)
{
    ApplicationBar.IsVisible = false;
    WaitForAppBarThenShowMenu();
}

private void WaitForAppBarThenShowMenu()
{
    if (ApplicationBar.IsVisible)
    {
        Dispatcher.BeginInvoke(WaitForAppBarThenShowMenu);
    }
    else
    {
        AnimatePopupMenuListCommands();
    }
}

OLD ANSWER - DOES NOT WORK I believe you can subscribe to the StateChanged event of the ApplicationBar and then start your story.

EventHandler<ApplicationBarStateChangedEventArgs> stateChanged = null;
stateChanged = (s,e) => 
{
    ApplicationBar.StateChanged -= stateChanged;
    AnimatePopupMenuListCommands(true);
};
ApplicationBar.StateChanged += stateChanged;
ApplicationBar.IsVisible = false;