Android programming to adjust screen brightness (background light) and keep the background light always on

This article describes the method of Android programming to adjust the screen brightness (background light) and keep the background light always on. Share it for your reference, as follows:

Applications written by Android can actually adjust the screen brightness. After checking the information, I found that this class contains parameters for adjusting the brightness:

 lp = getWindow().getAttributes();
 = 0.1f;

The parameter screenBrightness is to set the screen brightness of 0.0f, and the screen brightest 1.0f,

On this basis, I added a SeekBar to adjust the screen brightness.

The code reference is as follows:

In addition, the following sentence must be included in the callback function getWindow().setAttributes(lp); otherwise it will not work. At the beginning, I set the value directly in the onCreate() function. Without this function, I can adjust it directly, but it will not work if I don't add it in the callback function.

public class BLightActivity extends Activity {
/** Called when the activity is first created. */
int Max_Brightness = 100;
SeekBar bSeekBar = null;
float fBrightness = 0.0f;
 lp = null;
  @Override
  public void onCreate(Bundle savedInstanceState) {
    (savedInstanceState);
    setContentView();
    bSeekBar = (SeekBar) findViewById();
    (seekListener);
    (Max_Brightness);
    lp = getWindow().getAttributes();
//     = 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;
 = fBrightness;
// This sentence must be added, otherwise the screen brightness will not workgetWindow().setAttributes(lp);
("FY_" + fBrightness);
}
};
}

Here is a way to keep the background light constant:

First, you need to obtain permissions:

Copy the codeThe code is as follows:

<uses-permission android:name=".WAKE_LOCK"></uses-permission>

Below is an example of the control code

public class test extends Activity{
  PowerManager powerManager = null;
  WakeLock wakeLock = null;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
     (savedInstanceState);
     ();
      = (PowerManager)(Context.POWER_SERVICE);
      = (PowerManager.FULL_WAKE_LOCK, "My Lock");
     ();
   }
  @Override
  protected void onResume() {
     ();
     // Re-acquire     ();
   }
   @Override
   protected void onPause() {
     ();
     // Release wakeLock when Activity is destroyed     ();
   }
 }

For more information about Android development, readers who are interested in reading the topic of this site:Android development introduction and advanced tutorial》

I hope this article will be helpful to everyone's Android programming design.