안드로이드 소스 - 버튼 클릭, 이미지

package com.example.ryan.myapplication;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;
import android.widget.RadioGroup;

public class MainActivity extends AppCompatActivity {
    ImageView image;
    RadioGroup group;

    //
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        image=(ImageView)findViewById(R.id.imageView
        );
        group=(RadioGroup)findViewById(R.id.radiogroup1);

    }
    //

    //
    public void onRadioButtonClicked(View view) {

     //
        switch (group.getCheckedRadioButtonId()) {
            case R.id.button1:
                    image.setImageResource(R.drawable.cat);

                break;

            case R.id.button2:
                    image.setImageResource(R.drawable.dog1);
                break;

            case R.id.button3:
                    image.setImageResource(R.drawable.dog2);
                break;
        }///
    }
    ///


}