DisplayMetrics displayMetrics = Application.getInstance().getResources().getDisplayMetrics();
int densityDpi = displayMetrics.densityDpi;
float scaledDensity = displayMetrics.scaledDensity;
float density = displayMetrics.density;
float xdpi = displayMetrics.xdpi;
float ydpi = displayMetrics.ydpi;
int width = displayMetrics.widthPixels;
int height = displayMetrics.heightPixels;
得到的数据：
七寸：densityDpi:160,scaledDensity：1.0,density:1.0,xdpi:116.634,ydpi:120.952,width:1024,height:552
十寸：densityDpi:160,scaledDensity：1.0,density:1.0,xdpi:116.634,ydpi:120.952,width:1024,height:552