我怎么能在Android的改变屏幕亮度？

我可以找到如何为应用程序做到这一点，但我想这样做的所有系统和永久（直到用户选项更改它）。

我并不需要设置它自定义值。只是亮度低的水平，中等亮度和最大的将是完美的。

有可能例如使用电源管理或类似的东西\\？

采用Android 2.0 +

  WindowManager.LayoutParams LP = getWindow（）的getAttributes（）。lp.screenBrightness =＆下;值从0到1取代;。getWindow（）setAttributes（LP）; 

How I can change screen brightness in Android?

I can find how to do this for application, but I want do it for all system and permanently (until user changes it in options).

I don't need to set it for custom value. Just low brightness level, Medium brightness and Maximum will be perfect.

It is possible for example with PowerManager or something like that \?

Using Android 2.0+.

WindowManager.LayoutParams lp = getWindow().getAttributes();
lp.screenBrightness = <value from 0 to 1>;
getWindow().setAttributes(lp);