#Ruler

//获取屏幕物理尺寸大小

Point point = new Point();

getWindowManager().getDefaultDisplay().getRealSize(point);

DisplayMetrics dm = getResources().getDisplayMetrics();

float physicsW = (point.x/ dm.xdpi)*25.4;

float physicsH = (point.y / dm.ydpi)*25.4;

CSDN： https://blog.csdn.net/zhao007z5/article/details/79923716

米尺绘制参考： https://github.com/lovely3x/WeightAndHeightMeasurer