Android写的应用程序其实可以调节屏幕亮度的,查了一下资料发现WindowManager.LayoutParams这个类就包含了调节亮度的参数:
WindowManager.LayoutParams lp = getWindow().getAttributes();
lp.screenBrightness = 0.1f;
其中参数screenBrightness就是设置屏幕亮度的0.0f屏幕最暗,1.0f屏幕最亮
在此基础上我又加了一个SeekBar来调节屏幕亮度,
代码参考如下:
此外在回调函数中必须有如下这句话 getWindow().setAttributes(lp); 否则不起作用。我在开始的时候在onCreate()函数中直接设的值,没有这个函数,就能直接调节,但是在回调函数中不加上就不起作用
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public class BLightActivity extends Activity { int Max_Brightness = 100; SeekBar bSeekBar = null; float fBrightness = 0.0f; WindowManager.LayoutParams lp = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); bSeekBar = (SeekBar) findViewById(R.id.bLightBar); bSeekBar.setOnSeekBarChangeListener(seekListener); bSeekBar.setMax(Max_Brightness); lp = getWindow().getAttributes(); // lp.screenBrightness = 0.1f; } OnSeekBarChangeListener seekListener = new OnSeekBarChangeListener() { public void onStopTrackingTouch(SeekBar seekBar) { // TODO Auto-generated method stub } public void onStartTrackingTouch(SeekBar seekBar) { // TODO Auto-generated method stub } public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { // TODO Auto-generated method stub fBrightness = (float)progress / (float)Max_Brightness; lp.screenBrightness = fBrightness; // 这句得加上,否则屏幕亮度不启作用 getWindow().setAttributes(lp); System.out.println("FY_" + fBrightness); } }; }
下面是介绍保持背景灯常量的方法:
首先是要获得权限 :
<uses-permission android:name="android.permission.WAKE_LOCK"></uses-permission>
下面是控制代码实例
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public class test extends Activity{ PowerManager powerManager = null; WakeLock wakeLock = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.setContentView(R.layout.main); this.powerManager = (PowerManager)this.getSystemService(Context.POWER_SERVICE); this.wakeLock = this.powerManager.newWakeLock(PowerManager.FULL_WAKE_LOCK, "My Lock"); this.wakeLock.acquire(); } @Override protected void onResume() { super.onResume(); // 重新获取 this.wakeLock.acquire(); } @Override protected void onPause() { super.onPause(); // 在Activity销毁的时候释放wakeLock this.wakeLock.release(); } }