import java.util.Random;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        GridView gridview =(GridView)findViewById(R.id.grid);
        gridview.setAdapter(new ImageAdapter(this));
    }
    public class ImageAdapter extends BaseAdapter{
     private Context mcontext;
     private int number=0;
     
     Random r = new Random();
     int num=r.nextInt(25);
     private Integer[] colorId={
       R.drawable.white,
       R.drawable.blue,
       R.drawable.red
       };
     
     public ImageAdapter(Context c){
      mcontext=c;
     }
     public int getCount(){
      return colorId.length+22;
     }
     public Object getItem(int position){
      return position;
     }
     public long getItemId(int position){
      return position;
     }
     public View getView(int position, View converView, ViewGroup parent){
      ImageView imageView;
      imageView = new ImageView(mcontext);
      
      if(num == number){
       imageView.setImageResource(colorId[2]);
       
       
      }
      else{
       imageView.setImageResource(colorId[0]);
       
      }
      number++;
      return imageView;
     }
    }
}

현재 랜덤으로 붉은색의 영역 주기 까지 만들엇구요

이제 각각의 영역에 클릭 효과를 주고 싶은데 어떻게 해야할지 잘모르겠네요 ㅠ