CODEWITHSUNDEEP
javaarraysrandom
Tim Heath
Tim Heath

Reputation: 11

How to generate a random image in Java

I am creating a dice game however I am not sure how to randomly generate the images so the results are random. What would be the best way to do this, I heard an array would be good but then do I need the case statements if I have an array. 

/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;
    }
};

Upvotes: 1

Views: 3292

Answers (1)

ctst
ctst

Reputation: 1680

You wouldn't need the case statement if you declare one (or two) array(s) of drawable images like (assuming R.drawable is the correct type):

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,...};

Then you can just write:

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

instead of your switch-code.

As requested a full working example which returns a random text:

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);
    }
}

Upvotes: 3

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