Android WindowManager的使用 & 添加 遮罩层 实现夜间模式

package com.example.testnight;

import android.app.Activity;
import android.content.Context;
import android.graphics.PixelFormat;
import android.os.Bundle;
import android.view.Gravity;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.view.WindowManager;
import android.widget.TextView;

public class MainActivity extends Activity {

	private WindowManager mWindowManager;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		mWindowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
	}

	public void night(View view) {
		WindowManager.LayoutParams lp = new WindowManager.LayoutParams(
				LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT,
				WindowManager.LayoutParams.TYPE_APPLICATION,
				WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE
						| WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
				PixelFormat.TRANSLUCENT);

		lp.gravity = Gravity.BOTTOM;// 可以自定义显示的位置
		lp.y = 10;// 距离底部的距离是10像素 如果是 top 就是距离top是10像素
		TextView textView = new TextView(this);

		textView.setBackgroundColor(0x99000000);
		mWindowManager.addView(textView, lp);
	}

}