java - 如何在 Java 中生成随机图像

Question

我正在创建一个骰子游戏，但我不确定如何随机生成图像以便结果是随机的。执行此操作的最佳方法是什么，我听说数组会很好，但是如果我有一个数组，我还需要 case 语句吗？

/When pause completed message sent to callback
class Roll extends TimerTask {
    public void run() {
        handler.sendEmptyMessage(0);
    }
}

//Receives message from timer to start dice roll
Callback callback = new Callback() {
    public boolean handleMessage(Message msg) {
        //Get roll result
        //Remember nextInt returns 0 to 5 for argument of 6
        //hence + 1
        switch(rng.nextInt(6)+1) {
        case 1:
            dice_picture.setImageResource(R.drawable.one);
            dice_picture2.setImageResource(R.drawable.five);
            break;
        case 2:
            dice_picture.setImageResource(R.drawable.two);
            dice_picture2.setImageResource(R.drawable.four);
            break;
        case 3:
            dice_picture.setImageResource(R.drawable.three);
            dice_picture2.setImageResource(R.drawable.five);
            break;
        case 4:
            dice_picture.setImageResource(R.drawable.four);
            dice_picture2.setImageResource(R.drawable.three);
            break;
        case 5:
            dice_picture.setImageResource(R.drawable.five);
            dice_picture2.setImageResource(R.drawable.two);
            break;
        case 6:
            dice_picture.setImageResource(R.drawable.six);
            dice_picture2.setImageResource(R.drawable.one);
            break;
        default:
        }
        rolling=false;  //user can press again
        return true;
    }
};

Answer 1

如果声明一个(或两个)可绘制图像数组(假设 R.drawable 是正确的类型)，则不需要 case 语句:

R.drawable[] dice= {R.drawable.one, R.drawable.two, R.drawable.three, R.drawable.four, R.drawable.five, R.drawable.six};
R.drawable[] dice2= {R.drawable.five, R.drawable.four,...};

然后你就可以写:

int randomNumber = rng.nextInt(6);
dice_picture.setImageResource(dice[randomNumber]);
dice_picture2.setImageResource(dice2[randomNumber]);

而不是你的开关代码。

根据要求返回随机文本的完整工作示例:

import java.util.Random;

public class RandomText {

    String[] texts={"Hello", "World", "Cafe-Babe"};

    public static void main(String[] args){
        RandomText randText = new RandomText();
        randText.performRandom();
    }

    void performRandom(){
        Random rand = new Random();
        printText(texts[rand.nextInt(texts.length)]);
    }

    static void printText(String text){
        System.out.println(text);
    }
}