Android获取屏幕宽度的4种方法和背光调节

方法一与方法二获取屏幕宽度的方法类似，只是获取WindowManager 对象时的途径不同。

方法一：

WindowManager wm = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE);
int width = wm.getDefaultDisplay().getWidth();
int height = wm.getDefaultDisplay().getHeight();

方法二：

WindowManager wm1 = this.getWindowManager();
int width1 = wm1.getDefaultDisplay().getWidth();
int height1 = wm1.getDefaultDisplay().getHeight();

方法三与方法四类似

方法三：

WindowManager manager = this.getWindowManager();
DisplayMetrics outMetrics = new DisplayMetrics();
manager.getDefaultDisplay().getMetrics(outMetrics);
int width2 = outMetrics.widthPixels;
int height2 = outMetrics.heightPixels;

方法四：

Resources resources = this.getResources();
DisplayMetrics dm = resources.getDisplayMetrics();
float density1 = dm.density;
int width3 = dm.widthPixels;
int height3 = dm.heightPixels;

/**
* 判断是否开启了自动亮度调节
*
* @param aContext
* @return
*/
public static boolean isAutoBrightness(ContentResolver resolver) {
boolean automicBrightness = false;
try {
automicBrightness = Settings.System.getInt(resolver,
Settings.System.SCREEN_BRIGHTNESS_MODE) == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
} catch (SettingNotFoundException e) {
e.printStackTrace();
}
return automicBrightness;
}

/**
* 获取屏幕的亮度
*
* @param activity
* @return
*/
public static int getScreenBrightness(Activity activity) {
int nowBrightnessValue = 0;
ContentResolver resolver = activity.getContentResolver();
try {
nowBrightnessValue = android.provider.Settings.System.getInt(
resolver, Settings.System.SCREEN_BRIGHTNESS);
} catch (Exception e) {
e.printStackTrace();
}
return nowBrightnessValue;
}

/**
* 修改屏幕的亮度
*
* @param activity
* @param brightness
*/
public static void setBrightness(Activity activity, int brightness) {
// Settings.System.putInt(activity.getContentResolver(),
// Settings.System.SCREEN_BRIGHTNESS_MODE,
// Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
WindowManager.LayoutParams lp = activity.getWindow().getAttributes();
lp.screenBrightness = Float.valueOf(brightness) * (1f / 255f);
activity.getWindow().setAttributes(lp);

}

/**
* 停止自动亮度调节
*
* @param activity
*/
public static void stopAutoBrightness(Activity activity) {
Settings.System.putInt(activity.getContentResolver(),
Settings.System.SCREEN_BRIGHTNESS_MODE,
Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
}

/**
* 开启亮度自动调节
*
* @param activity
*/
public static void startAutoBrightness(Activity activity) {
Settings.System.putInt(activity.getContentResolver(),
Settings.System.SCREEN_BRIGHTNESS_MODE,
Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);
}

/**
* 保存亮度设置状态
*
* @param resolver
* @param brightness
*/
public static void saveBrightness(ContentResolver resolver, int brightness) {
Uri uri = android.provider.Settings.System.getUriFor("screen_brightness");
android.provider.Settings.System.putInt(resolver, "screen_brightness",brightness);
// resolver.registerContentObserver(uri, true, myContentObserver);
resolver.notifyChange(uri, null);
}