Question

所以我试图这样做：当你点击图像时，中心的文字变成了数组中的一个随机元素，但是我希望每一个出现过一次的元素都不再出现......我试着这样做这但它没有用，请在这里帮助我!!

package com.example.bibiwars.skills;


import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;


import java.util.Random;


public class MainActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


            ImageView img = (ImageView) findViewById(R.id.logo);
            img.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            //ToastMessage to test the click ::::::
            Toast.makeText(MainActivity.this, "Clicked!!",Toast.LENGTH_SHORT).show();


            TextView text = (TextView) findViewById(R.id.text);
            String[] Array = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"};
            int rnd = new Random().nextInt(Array.length);
            while (Array[rnd].equals("0"))
               {rnd = new Random().nextInt(Array.length);}
            text.setText(Array[rnd]);
            Array[rnd] = "0";
        }

    });
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}



}

Answer 1

您应该将数组保存为字段变量，并在选择后实际删除一个条目。这样你就不会两次相同。

package com.example.bibiwars.skills;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.Random;


public class MainActivity extends ActionBarActivity {
final ArrayList<String> places =  = new ArrayList<>(Arrays.asList("a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"));

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ImageView img = (ImageView) findViewById(R.id.logo);
    img.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            //ToastMessage to test the click ::::::
            Toast.makeText(MainActivity.this, "Clicked!!",Toast.LENGTH_SHORT).show();
            TextView text = (TextView) findViewById(R.id.text);
            if(places.size() >0)
            {
                int rnd = new Random().nextInt(places.size());
                text.setText(places.get(rnd));
                places.remove(rnd);
            }
        }

    });
}
//... other methods...
}

Answer 2

shuffle array

// Implementing Fisher–Yates shuffle
  static void shuffleArray(int[] ar)
  {
    Random rnd = new Random();
    for (int i = ar.length - 1; i > 0; i--)
    {
      int index = rnd.nextInt(i + 1);
      // Simple swap
      int a = ar[index];
      ar[index] = ar[i];
      ar[i] = a;
    }
  }

当你点击show next array element。

试图使数组元素只出现一次

2 个答案: