003.Listener

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:background="@drawable/piano"
        android:text="1" />

    <Button
        android:id="@+id/button2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/button1"
        android:background="@drawable/piano"
        android:text="2" />

    <Button
        android:id="@+id/button3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/button2"
        android:background="@drawable/piano"
        android:text="3" />

    <Button
        android:id="@+id/button4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/button3"
        android:background="@drawable/piano"
        android:text="4" />

    <Button
        android:id="@+id/button5"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/button4"
        android:background="@drawable/piano"
        android:text="5" />

    <Button
        android:id="@+id/button6"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/button5"
        android:background="@drawable/piano"
        android:text="6" />

    <Button
        android:id="@+id/button7"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/button6"
        android:background="@drawable/piano"
        android:text="7" />

    <Button
        android:id="@+id/button8"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/button7"
        android:background="@drawable/piano"
        android:text="8" />

</RelativeLayout>

package com.example.app3;

import android.app.Activity;
import android.media.AudioManager;
import android.media.SoundPool;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {

    Button btn1, btn2, btn3, btn4, btn5, btn6, btn7, btn8;
    SoundPool soundPool;
    int sounds[] = new int[8];

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

        btn1 = (Button) this.findViewById(R.id.button1);
        btn2 = (Button) this.findViewById(R.id.button2);
        btn3 = (Button) this.findViewById(R.id.button3);
        btn4 = (Button) this.findViewById(R.id.button4);
        btn5 = (Button) this.findViewById(R.id.button5);
        btn6 = (Button) this.findViewById(R.id.button6);
        btn7 = (Button) this.findViewById(R.id.button7);
        btn8 = (Button) this.findViewById(R.id.button8);

        soundPool = new SoundPool(8, AudioManager.STREAM_MUSIC, 0);

        sounds[0] = soundPool.load(this, R.raw.white1, 1);
        sounds[1] = soundPool.load(this, R.raw.white2, 1);
        sounds[2] = soundPool.load(this, R.raw.white3, 1);
        sounds[3] = soundPool.load(this, R.raw.white4, 1);
        sounds[4] = soundPool.load(this, R.raw.white5, 1);
        sounds[5] = soundPool.load(this, R.raw.white6, 1);
        sounds[6] = soundPool.load(this, R.raw.white7, 1);
        sounds[7] = soundPool.load(this, R.raw.white8, 1);

        View.OnClickListener listener1 = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                soundPool.play(sounds[0], 1, 1, 1, 0, 1);
            }
        };
        View.OnClickListener listener2 = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                soundPool.play(sounds[1], 1, 1, 1, 0, 1);
            }
        };
        View.OnClickListener listener3 = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                soundPool.play(sounds[2], 1, 1, 1, 0, 1);
            }
        };
        View.OnClickListener listener4 = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                soundPool.play(sounds[3], 1, 1, 1, 0, 1);
            }
        };
        View.OnClickListener listener5 = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                soundPool.play(sounds[4], 1, 1, 1, 0, 1);
            }
        };
        View.OnClickListener listener6 = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                soundPool.play(sounds[5], 1, 1, 1, 0, 1);
            }
        };
        View.OnClickListener listener7 = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                soundPool.play(sounds[6], 1, 1, 1, 0, 1);
            }
        };
        View.OnClickListener listener8 = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                soundPool.play(sounds[7], 1, 1, 1, 0, 1);
            }
        };

        btn1.setOnClickListener(listener1);
        btn2.setOnClickListener(listener2);
        btn3.setOnClickListener(listener3);
        btn4.setOnClickListener(listener4);
        btn5.setOnClickListener(listener5);
        btn6.setOnClickListener(listener6);
        btn7.setOnClickListener(listener7);
        btn8.setOnClickListener(listener8);
    }
}