NotificationCompat.Builder未设置大小图标

Question

这就是我设置图标的方式。但是这两个图标都没有设置。显示大图标的默认Android图标。我该如何解决这个问题？

NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context)
                .setLargeIcon(BitmapFactory.decodeResource(context.getResources(), R.mipmap.ic_launcher))
                .setSmallIcon(R.drawable.ic_alarm_on_white_24dp)
                .setContentTitle(context.getResources().getString(R.string.app_name))
                .setTicker(mTitle)
                .setContentText(mTitle)
                .setContentIntent(mClick)
                .setAutoCancel(true)
                .setOnlyAlertOnce(true);