Using a Storyboard animation on a programatically-added control

Question

I'm trying to fade in a new control to my application's "app" area which is programatically added after the existing controls are removed. My code looks like this:

     void settingsButton_Clicked(object sender, EventArgs e)
 {
  ContentCanvas.Children.Clear();

  // Fade in settings panel
  NameScope.SetNameScope(this, new NameScope());

  SettingsPane s = new SettingsPane();
  s.Name = "settingsPane";

  this.RegisterName(s.Name, s);
  this.Resources.Add(s.Name, s);

  Storyboard sb = new Storyboard();

  DoubleAnimation settingsFade = new DoubleAnimation();
  settingsFade.From = 0;
  settingsFade.To = 1;
  settingsFade.Duration = new Duration(TimeSpan.FromSeconds(0.33));
  settingsFade.RepeatBehavior = new RepeatBehavior(1);
  Storyboard.SetTargetName(settingsFade, s.Name);
  Storyboard.SetTargetProperty(settingsFade, new PropertyPath(UserControl.OpacityProperty));

  ContentCanvas.Children.Add(s);

  sb.Children.Add(settingsFade);
  sb.Begin();
 }

However, when I run this code, I get the error "No applicable name scope exists to resolve the name 'settingsPane'."

What am I possibly doing wrong? I'm pretty sure I've registered everything properly :(

Answer 1

I wouldn't hassle with the NameScopes etc. and would rather use Storyboard.SetTarget instead.

var b = new Button() { Content = "abcd" };
stack.Children.Add(b);

var fade = new DoubleAnimation()
{
    From = 0,
    To = 1,
    Duration = TimeSpan.FromSeconds(5),
};

Storyboard.SetTarget(fade, b);
Storyboard.SetTargetProperty(fade, new PropertyPath(Button.OpacityProperty));

var sb = new Storyboard();
sb.Children.Add(fade);

sb.Begin();

Answer 2

I agree, the namescopes are probably the wrong thing to use for this scenario. Much simpler and easier to use SetTarget rather than SetTargetName.

In case it helps anyone else, here's what I used to highlight a particular cell in a table with a highlight that decays to nothing. It's a little like the StackOverflow highlight when you add a new answer.

    TableCell cell = table.RowGroups[0].Rows[row].Cells[col];

    // The cell contains just one paragraph; it is the first block
    Paragraph p = (Paragraph)cell.Blocks.FirstBlock;

    // Animate the paragraph: fade the background from Yellow to White,
    // once, through a span of 6 seconds.

    SolidColorBrush brush = new SolidColorBrush(Colors.Yellow);
    p.Background = brush;
    ColorAnimation ca1 = new ColorAnimation()
    {
            From = Colors.Yellow,
            To = Colors.White,
            Duration = new Duration(TimeSpan.FromSeconds(6.0)),
            RepeatBehavior = new RepeatBehavior(1),
            AutoReverse = false,
    };

    brush.BeginAnimation(SolidColorBrush.ColorProperty, ca1);

Answer 3

I solved the problem using this as parameter in the begin method, try:

sb.Begin(this);

Because the name is registered in the window.