Android animate character in SurfaceView

问题:

I want to animate a character (for eg run a dog) on screen. AnimationDrawable seemed a perfect fit for this, and AnimationDrawable requires an ImageView. How do I add and move around the ImageView in SurfaceView?

Thanks.

回答1:

You don't need an ImageView.

If your animation is an XML Drawable, you can load it directly from the Resources into an AnimationDrawable variable:

Resources res = context.getResources();
AnimationDrawable animation = (AnimationDrawable)res.getDrawable(R.drawable.anim);      

Then set it's bounds and draw on the canvas:

animation.setBounds(left, top, right, bottom);
animation.draw(canvas);

You also need to manually set the animation to run on it's next scheduled interval. This can be accomplished by creating a new Callback using animation.setCallback, then instantiating an android.os.Handler and using the handler.postAtTime method to add the next animation frame to the current Thread's message queue.

animation.setCallback(new Callback() {

  @Override
  public void unscheduleDrawable(Drawable who, Runnable what) {
    return;
  }

  @Override
  public void scheduleDrawable(Drawable who, Runnable what, long when) {
    //Schedules a message to be posted to the thread that contains the animation
    //at the next interval. 
    //Required for the animation to run. 
    Handler h = new Handler(); 
    h.postAtTime(what, when);
  }

  @Override
  public void invalidateDrawable(Drawable who) {
    return;
  }
});

animation.start();

回答2:

With a SurfaceView it is your responsibility to draw everything within it. You do not need AnimationDrawable or any view to render your character on it. Take a look onto Lunar Lander example game from Google.