Android獲取屏幕寬高的四種方法

推薦使用前兩種：

方法1：

WindowManager manager = this.getWindowManager();
		DisplayMetrics outMetrics = new DisplayMetrics();
		manager.getDefaultDisplay().getMetrics(outMetrics);
		int width = outMetrics.widthPixels;
		int height = outMetrics.heightPixels;

方法2：

Resources resources = this.getResources();
		DisplayMetrics dm = resources.getDisplayMetrics();
		float density = dm.density;
		int width = dm.widthPixels;
		int height = dm.heightPixels;

方法3：

WindowManager wm = (WindowManager) this
				.getSystemService(Context.WINDOW_SERVICE);
		int width = wm.getDefaultDisplay().getWidth();
		int height = wm.getDefaultDisplay().getHeight();

方法4：

WindowManager wm1 = this.getWindowManager();
		int width1 = wm1.getDefaultDisplay().getWidth();
		int height1 = wm1.getDefaultDisplay().getHeight();