Question

I have a For..Each loop which loops trough all grid’s rectangles and changes the fill of them randomly. I change the fill with a color animation. Here’s my code:

        Dim rand as new random
        Dim changeColor As New Animation.ColorAnimation

        changeColor.Duration = TimeSpan.FromSeconds(0.5)

        For Each r As Rectangle In Grid.Children
            changeColor.From = ColorConverter.ConvertFromString(r.Fill.ToString)            
            Dim i As Integer = rand.Next(0, 2)
            Select Case i
                Case 0
                    changeColor.To = Colors.White
                Case 1
                    changeColor.To = Colors.Gray
            End Select
            Animation.Storyboard.SetTarget(changeColor, r)
            Animation.Storyboard.SetTargetProperty(changeColor, New PropertyPath("Fill.Color"))
            Dim sb As New Animation.Storyboard
            sb.Children.Add(changeColor)

            sb.Begin()
            System.Threading.Thread.Sleep(0.5)
        Next

The problem is that the loop doesn’t sleep. I want to trigger the animation, then wait until the rectangle fill is changed and then continue with the rest, but it seems that all of the rectangles fill are changed in the same time. So what I’m doing wrong?

Answer 1

You sleep the UI thread, so both the loop and all rendering is halted. You could try a method like this one i wrote for another question.

Edit: Also change the time as pointed out by Michael Holdshteyn.