Introduction - If you have any usage issues, please Google them yourself
Principle: double buffering the principle of this image can be understood: the computer screen as a blackboard. First of all, we in the memory environment to create a virtual blackboard,And then draw a complex graphic on the blackboard, and so on when all the graphics are drawn, and then once again in the memory drawn graphics copy to another blackboard (screen) on.Take this method can improve the drawing speed, greatly improve the drawing effect.