WPF Newbie question

Question

I'm trying to learn WPF animations and am currently confused by quite a few things:

I used tools like processing, where you have a simple method which is called n times per minute, where n is the frame rate.

The way to do animations in WPF is to modify a property. If i use for example DoubleAnimation then a double is increased as the animation proceeds. But this is not exactly what I want. I want that in every cycle some properties are increased, some are modified by random and some are modified by user interaction. How can I do this in WPF?

What is also confusing me is the fact that WPF supports multiple animations at the same time. How does this work? Is there a thread for every animation or just one for all animations.

I used gdi with c# some time ago. I even could use multiple threads for drawing; As far as I remember I just had to insert all the drawing commands in some queue and then windows took care of them.. I have no idea how this is handled with WPF.

Answer 1

On a basic level, WPF animations are just the same as any other kind of animation: internally a timer ticks and some properties are modified which lead to a different picture when drawn to the screen.

WPF does all the leg work for you to be able to specify animations relative to wall-clock time, like "move that box at 3mm per second to the left". For more complex scenarios you might want to code up your own Animation, see the Custom Animation Overview article on the MSDN.

Regarding threading, WPF works the same as GDI: There is one Thread that handles all the interaction with the WPF model and you can only talk to WPF Controls if you're running on this thread. You can use the Dispatcher to "send" code to this thread if you are free threading. Actual drawing to DirectX is done in a separate thread, but that is of no concern to casual users of the API.

Answer 2

You can run several animations at the same time by putting them into a StoryBoard.

You can use the animation's BeginTime to get one animation to start after another.

You can use the key frames version (DoubleAnimationUsingKeyFrames) or the path version (DoubleAnimationUsingPath) to create complex non-linear animations.