得到设备屏幕宽高：
WindowManager wManager = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);
Display display = wManager.getDefaultDisplay();
int width = display.getWidth();
int height = display.getHeight();
设置View大小：
LayoutParams lp = mView.getLayoutParams();
lp.width = width/2;
lp.height = height/3;
mView.setLayoutParams(lp);