Question

I’m kinda new to WPF and just started looking into animations, and just for fun i started creating the old-school game Frogger (the one with a frog that has to cross a river/road while not getting hit by cars etc).

I made the animation for the log of wood moving across the screen in the river:

<Canvas>
        <Rectangle Name="shape_WaterBackground" Fill="#1E90FF" Height="20" Width="260" Canvas.Top="240"/>
        <Rectangle Name="shape_Lumber" Width="40" Canvas.Top="240" Fill="Brown" Height="16" Margin="0,2,0,0" />
        <Image Name="Froggy" Height="20" Width="20" Canvas.Top="300" Canvas.Left="120" Source="Froggy.jpg" />             
</Canvas>

And the code-behind for this particular animation:

DoubleAnimation Animate_Lumber_Movement = new DoubleAnimation(-40, 280, TimeSpan.Parse("0:0:7"));

Animate_Lumber_Movement.RepeatBehavior = RepeatBehavior.Forever;

shape_Lumber.BeginAnimation(Canvas.LeftProperty, Animate_Lumber_Movement);

Now my question is, how do I handle when the log reaches a certain point. The reason is (like you’ve probably already guessed) that I would like to know how to execute an action mid-way through the animation (a different point or time in the animation, and not a static) ofc without stopping the animation.

Its somewhat the same problem I have as described in here:How to determine when an animated sprite reaches a point?, but for C# WPF.

As an example in the code above, i want the frog to survive if it jumps towards the river and its Canvas.Leftproperty matches the animated logs, or otherwise drown.

Any suggestion is greatly appreciated (but bear in mind that I’m a newbie)

Sorry for the not-so-well-explained question 🙂

Thank you and best regards

Lodal

Answer 1

Since you’re just animating the Canvas.Left property, you could always just set up a DispatcherTimer and read it (Canvas.GetLeft or Canvas.GetTop).

Although, maybe this is just me, but conceptually, WPF animations are more for short spurts, sort of like screen transitions and the like – not really for handling entire game animations. If that’s your aim, you’re probably just better off handling the animation yourself (set up a DispatcherTimer, and then on each tick you would update your game state).