@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);  //獲取屏幕的長度和寬度    DisplayMetrics dm = new DisplayMetrics();    getWindowManager().getDefaultDisplay().getMetrics(dm);    int width = dm.widthPixels;    int heigh = dm.heightPixels;        Dialog d = new Dialog(this);    d.setTitle(width + "*" + heigh);    d.show(); }