使用eclipse编写一个Android实验音乐播放器代码

以下是一个简单的Android音乐播放器的代码示例，使用Eclipse开发：

MainActivity.java

import android.app.Activity;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.TextView;

public class MainActivity extends Activity {

    private Button playButton;
    private Button pauseButton;
    private SeekBar seekBar;
    private TextView currentSongTime;
    private TextView totalSongTime;
    private MediaPlayer mediaPlayer;
    private Handler handler;

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

        playButton = (Button) findViewById(R.id.play_button);
        pauseButton = (Button) findViewById(R.id.pause_button);
        seekBar = (SeekBar) findViewById(R.id.seek_bar);
        currentSongTime = (TextView) findViewById(R.id.current_song_time);
        totalSongTime = (TextView) findViewById(R.id.total_song_time);

        handler = new Handler();

        mediaPlayer = MediaPlayer.create(this, R.raw.song);

        seekBar.setMax(mediaPlayer.getDuration());

        playButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mediaPlayer.start();
                updateSeekBar();
            }
        });

        pauseButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mediaPlayer.pause();
            }
        });

        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                if(fromUser){
                    mediaPlayer.seekTo(progress);
                    updateSeekBar();
                }
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {

            }
        });
    }

    private void updateSeekBar() {
        seekBar.setProgress(mediaPlayer.getCurrentPosition());
        currentSongTime.setText(millisecondToString(mediaPlayer.getCurrentPosition()));
        totalSongTime.setText(millisecondToString(mediaPlayer.getDuration()));

        if(mediaPlayer.isPlaying()){
            Runnable runnable = new Runnable() {
                @Override
                public void run() {
                    updateSeekBar();
                }
            };
            handler.postDelayed(runnable, 1000);
        }
    }

    private String millisecondToString(int millisecond){
        int second = millisecond/1000;
        int minute = second/60;
        second = second%60;
        return String.format("%02d:%02d", minute, second);
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/current_song_time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="00:00"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentBottom="true"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"/>

    <TextView
        android:id="@+id/total_song_time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="00:00"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentBottom="true"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"/>

    <SeekBar
        android:id="@+id/seek_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_above="@id/current_song_time"
        android:layout_below="@id/play_button"/>

    <Button
        android:id="@+id/play_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Play"
        android:layout_centerVertical="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"/>

    <Button
        android:id="@+id/pause_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Pause"
        android:layout_centerVertical="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"/>

</RelativeLayout>

在这个实现中，我们使用了Android提供的MediaPlayer来播放音乐。SeekBar用于显示歌曲播放进度，并允许用户跳转到歌曲的任意位置。我们还使用Handler来定期更新SeekBar和当前播放时间。