android系统设置-修改睡眠时间，修改背光强度

1.设置睡眠时间的例子

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

//当睡眠值为-1的时候，则不睡眠。 输入的单位为毫秒
super.onCreate(savedInstanceState);
try {
SharedPreferences settings=getSharedPreferences("net.mensus.togglescreen", MODE_PRIVATE);
ContentResolver c=getContentResolver();
int val=android.provider.Settings.System.getInt(getContentResolver(), SCREEN_OFF_TIMEOUT);
if(val==-1 || val==0) {
int nval=settings.getInt("ScreenTimeout",60000);
if(nval<=0) nval=60000;
String t;
if(nval==30000) t="1/2 min";
else if(nval>=60000) t=""+(nval/60000)+" min";
else t=""+(nval/1000)+" sec";
Toast.makeText(this, "Screen Timeout set to "+ t,  Toast.LENGTH_LONG).show();
android.provider.Settings.System.putInt(getContentResolver(), SCREEN_OFF_TIMEOUT, nval);
} else {
android.provider.Settings.System.putInt(getContentResolver(), SCREEN_OFF_TIMEOUT, -1);
Toast.makeText(this, "Disabled Screen Timeout", Toast.LENGTH_LONG).show();
SharedPreferences.Editor editor = settings.edit();
editor.putInt("ScreenTimeout",val);
editor.commit();
}
} catch(Throwable er) {
Toast.makeText(this, "Error "+er.getMessage(), Toast.LENGTH_LONG).show();
} finally {
finish();
}
}

int val=android.provider.Settings.System.getInt(getContentResolver(), SCREEN_OFF_TIMEOUT);

获得系统的睡眠时间，单位是毫秒

android.provider.Settings.System.putInt(getContentResolver(), SCREEN_OFF_TIMEOUT, nval);

设置系统的睡眠时间。

注意：在manifest中要加入这句：<uses-permission android:name="android.permission.WRITE_SETTINGS" />

2.设置系统背光强度

    private final int MAXIMUM_BACKLIGHT = 255;
    private final int MINIMUM_BACKLIGHT = 10;

// 设置自动背光
private void  setAutoBright(boolean mode) {
if (mode) {
Settings.System.putInt(mainActivity.getContentResolver(), System.SCREEN_BRIGHTNESS_MODE, System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);
//autoOnOrOff.setText(String.valueOf(getAutoBrightnessMode()));
} else {
Settings.System.putInt(mainActivity.getContentResolver(), System.SCREEN_BRIGHTNESS_MODE, System.SCREEN_BRIGHTNESS_MODE_MANUAL);
///autoOnOrOff.setText(String.valueOf(getAutoBrightnessMode()));
}

java.lang.System.out.println("test" +  + getAutoBrightnessMode());
}

//判断是否自动背光  返回值为0表示false 1表示true
private int getAutoBrightnessMode() {
int brightnessMode;

try {
brightnessMode = Settings.System.getInt(mainActivity.getContentResolver(), System.SCREEN_BRIGHTNESS_MODE);
} catch (Settings.SettingNotFoundException e) {
e.printStackTrace();
brightnessMode = -10000;
}
return brightnessMode;
}

//刷新背光  如果参数为小于零，则为自动背光
private void refreshBrightness(float brightness) {
WindowManager.LayoutParams lp = mainActivity.getWindow().getAttributes();
if (brightness < 0) {
lp.screenBrightness = WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_NONE;
} else {
lp.screenBrightness = brightness;
}
mainActivity.getWindow().setAttributes(lp);

setBrightness(brightness < 0 ? WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_NONE : brightness);
}

private int getBrightnessLevel() {
try {
int value = Settings.System.getInt(mainActivity.getContentResolver(), System.SCREEN_BRIGHTNESS);
return value;
} catch (SettingNotFoundException e) {
return MAXIMUM_BACKLIGHT;
}
}

参考网址： http://www.mensus.net/phone/toggle.shtml