问题
I'm trying to get a background in a live wallpaper to behave like a regular wallpaper with regard to scrolling when the user changes homescreens. I know the method required for this is onOffestsChanged, but I can't seem to get it working.
Does anyone have advice or a code snippet to get this working?
回答1:
Have your engine implement onOffsetsChanged. The xOffset variable is a float value from 0 to 1 with 0 being the leftmost screen and 1 being the rightmost. Use the width of the screen (from onSurfaceChanged) and the width of your image to determine the left x coordinate with which to draw your image.
(screenWidth - yourImageWidth) * (1 - xOffset);
This should work with both screenWidth > yourImageWidth and screenWidth < yourImageWidth.
来源：https://stackoverflow.com/questions/5044363/parallax-effect-scrolling-of-live-wallpaper-background