How turn On/Off android display backlight using C#

Someone knows how to turn On/Off android display backlight using C# only in Unity? I don't like plugins, and I don't want to make one of my own. I know that you can disable the display while using the proximity sensor... but i don't know how to do it in C# in Unity3d...

Maybe the android.provider.Settings.System.SCREEN_BRIGHTNESS will help but i don't know how to change the value (1-255) in Unity3d with C# If someone have a solution i would be very happy. thank you

here is my code.... but it doesn't work as expected... also i like to know how to set the SCREEN_BRIGHTNESS using C# and Unity... if someone has a working example script or know how to change this... plz help out... many many thx M.

Code (CSharp):

1. public void CheckScreenBrightness()
2. {
3.      using (var actClass = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
4.      {
5.          var context = actClass.GetStatic<AndroidJavaObject>("SCREEN_BRIGHTNESS");
6.          AndroidJavaClass systemSetting = new AndroidJavaClass("android.provider.Settings$System");
7.  
8.          var screenbrightness = systemSetting.CallStatic<int>("getInt", context.Call<AndroidJavaObject>("getContentResolver"), "SCREEN_BRIGHTNESS");
9.        
10.          Debug.Log("Screen Brightness = " + screenbrightness);
11.      }
12. }

 

Were you able to find a solution? I am having a similar issue.