在用GDI实时显示多张图片时，会出现屏闪，利用双缓存可以解决这个问题-In real-time display with GDI multiple pictures, flash screen will appear, use double-buffering can solve this problem

VC++利用掩码位图制作透明图片，类似于Flash制作中的遮罩一样，可以把图像遮挡起来，形成一定的形状。-VC++ use the mask making transparent bitmap images, similar to the production of the mask, like Flash, you can put an image block to form a certain shape.