Android中如何判断app是否在前台

	public static boolean isAppInForeground(Context context) {
		ActivityManager am = (ActivityManager) context
				.getSystemService(Context.ACTIVITY_SERVICE);
		List<RunningTaskInfo> tasks = am.getRunningTasks(1);
		if (!tasks.isEmpty()) {
			ComponentName topActivity = tasks.get(0).topActivity;
			if (topActivity.getPackageName().equals(context.getPackageName())) {
				return true;
			}
		}
		return false;
	}