int pixel = bitmap.getPixel(x, y);报错

当xml里设置match_parent时，这句代码（ int pixel = bitmap.getPixel(x, y);）在某些手机上会报错（x must be <= bitmap.getWidth()）。

可在构造函数里强制:
int widthAndHeight = ViewGroup.LayoutParams.WRAP_CONTENT;
ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(widthAndHeight, widthAndHeight);
setLayoutParams(params);