java - 如何从随机数系列中排除某个数字？

Question

我正在开发一个骰子游戏。我正在生成一个随机数字，介于 1 到 6 之间。我的骰子显示相同的数字。所以它工作得很好。但是在一个条件之后，我希望2不能出现，那么我怎样才能在1到6之间删除2。这是我的代码。

Random rng = new Random();
btnSpin.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            if (!rolling) {
                dice_picture.setImageResource(R.drawable.dice3d);
                timer.schedule(new Roll(), 400);
            }
        }
    });
}

// code of dice...
class Roll extends TimerTask {
    public void run() {
        handler.sendEmptyMessage(0);
    }
}

Callback callback = new Callback() {
    public boolean handleMessage(Message msg) {
        switch (rng.nextInt(6) + 1) {
        case 1:
            dice_picture.setImageResource(R.drawable.one);
            icon = "one";
            Toast.makeText(getApplicationContext(),
                    "The value is one" + one, Toast.LENGTH_SHORT).show();
            break;
        case 2:
            dice_picture.setImageResource(R.drawable.two);
            icon = "two";
            Toast.makeText(getApplicationContext(),
                    "The value is two" + two, Toast.LENGTH_SHORT).show();
            break;
        case 3:
            dice_picture.setImageResource(R.drawable.three);
            icon = "three";
            Toast.makeText(getApplicationContext(),
                    "The value is three" + three, Toast.LENGTH_SHORT)
                    .show();
            break;
        case 4:
            dice_picture.setImageResource(R.drawable.four);
            icon = "four";
            Toast.makeText(getApplicationContext(),
                    "The value is four" + four, Toast.LENGTH_SHORT).show();
            break;
        case 5:
            dice_picture.setImageResource(R.drawable.five);
            icon = "five";
            Toast.makeText(getApplicationContext(),
                    "The value is five" + five, Toast.LENGTH_SHORT).show();
            break;
        case 6:
            dice_picture.setImageResource(R.drawable.six);
            icon = "six";
            Toast.makeText(getApplicationContext(),
                    "The value is six" + six, Toast.LENGTH_SHORT).show();
            break;
        default:
        }
        rolling = false; // user can press again
        return true;
    }
};

Answer 1

您首先使用允许的值填充列表，然后在此列表的范围内生成随机索引。

List<Integer> allowedValues = Arrays.asList(1,3,4,5,6);
Random rd = new Random();
int selected = allowedValues(rd.nextInt(allowedValues.size()));