二、优化灭屏动画时间

优化灭屏动画时间可以在一定程度上减少灭屏时间，,主要修改DisplayPowerController.java类，具体优化方案如下：

 
--- a/frameworks/base/services/core/java/com/android/server/display/DisplayPowerController.java
 
@@ final class DisplayPowerController implements AutomaticBrightnessController.Call

     // The minimum reduction in brightness when dimmed.

     private static final int SCREEN_DIM_MINIMUM_REDUCTION = 10;

-    private static final int COLOR_FADE_ON_ANIMATION_DURATION_MILLIS = 250;

-    private static final int COLOR_FADE_OFF_ANIMATION_DURATION_MILLIS = 400;

+    private static final int COLOR_FADE_ON_ANIMATION_DURATION_MILLIS = 25;

+    private static final int COLOR_FADE_OFF_ANIMATION_DURATION_MILLIS = 40;

     private static final int MSG_UPDATE_POWER_STATE = 1;

     private static final int MSG_PROXIMITY_SENSOR_DEBOUNCED = 2;