涂鸦里面实现了颜色的更换和背景的更换可以把图库里面的图片做为背景，而手写就没有那么强大了，希望大家完善实现背景的更换-Graffiti inside the realization of the color of the replacement and the replacement of the background can be the picture inside the picture as the background, and handwriting is not so strong