android 判断app是否处于前台

/**
     * app是否在后台
     *
     * @param context
     * @return true 是 false 不是
     */
    public static boolean isBackground(Context context) {
        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        List<ActivityManager.RunningTaskInfo> tasks = am.getRunningTasks(1);
        if (!tasks.isEmpty()) {
            ComponentName topActivity = tasks.get(0).topActivity;
            StaticMethod.debugEMSG(topActivity.getPackageName() + " : " + context.getPackageName());
            if (!topActivity.getPackageName().equals(context.getPackageName())) {
                return true;
            }
        }
        return false;
    }