获取屏幕的宽高和密度

/**
 * 初始化当前设备屏幕宽高
 */
private void initScreenSize() {
    DisplayMetrics curMetrics = getApplicationContext().getResources().getDisplayMetrics();
    screenWidth = curMetrics.widthPixels;
    screenHeight = curMetrics.heightPixels;
    screenDensity = curMetrics.density;
}