达内课程-音乐播放器v1.0(中)
学习了达内课程-音乐播放器v1.0(上)我们接着完善我们的代码
MediaPlayer类支持主流的音频、视频格式播放
常用方法：
void reset()//重置
void setDataSource(String)//设置数据源，参数可以是音频/视频路径
void prepare()//加载音频/视频数据，必须在setDataSource()方法后调用
void start()//开始播放，必须在prepare()方法后调用
void stop()//停止播放
int getCurrentPosition;//获取当前播放到的位置，返回值毫秒
void seekTo(int);//快进到指定位置，参数是毫秒为单位的数值
效果图
代码
activity_main.xml
<RelativeLayout android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical">
<ListView
android:id="@+id/listview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/ll_music_info"/>
<LinearLayout
android:id="@+id/ll_music_info"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/ll_buttons"
android:padding="10dp">
<TextView
android:id="@+id/tv_current_music_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="请选择播放歌曲"/>
LinearLayout>
<LinearLayout
android:id="@+id/ll_buttons"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:gravity="center"
>
<ImageButton
android:id="@+id/ib_previous"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@android:drawable/ic_media_previous"
/>
<ImageButton
android:id="@+id/ib_play"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Play"
android:src="@android:drawable/ic_media_play"/>
<ImageButton
android:id="@+id/ib_next"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Next"
android:src="@android:drawable/ic_media_next"/>
LinearLayout>
RelativeLayout>
item_music.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp">
<TextView
android:id="@+id/tv_music_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:maxLines="1"
android:text="title"
android:textColor="#222222"
android:textSize="15dp"
/>
<TextView
android:id="@+id/tv_music_path"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:maxLines="1"
android:layout_below="@+id/tv_music_title"
android:text="path......"
android:textColor="#999999"
android:textSize="15dp"
/>
RelativeLayout>
MainActivity
public class MainActivity extends AppCompatActivity {
private List musics;
private ListView listView;
private MusicAdapter adapter;
private TextView tvCurrentMusicTitle;
private ImageButton ibPrevious;//上一首按钮
private ImageButton ibPlay;//播放/暂停按钮
private ImageButton ibNext;//下一首按钮
private MediaPlayer mediaPlayer;
private int pausePosition;//歌曲暂停时间
private int currentMusicIndex;//当前播放歌曲索引
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//初始化控件
musics = new ArrayList();
ibPrevious = findViewById(R.id.ib_previous);
ibPlay = findViewById(R.id.ib_play);
ibNext = findViewById(R.id.ib_next);
tvCurrentMusicTitle = findViewById(R.id.tv_current_music_title);
listView = findViewById(R.id.listview);
mediaPlayer = new MediaPlayer();
//为底部按钮添加点击事件
InnerClassOnClickListener listener = new InnerClassOnClickListener();
ibPrevious.setOnClickListener(listener);
ibPlay.setOnClickListener(listener);
ibNext.setOnClickListener(listener);
//为listview添加点击事件
OnItemClickListener onItemClickListener = new OnItemClickListener();
listView.setOnItemClickListener(onItemClickListener);
//获取数据
getData();
//通过日志检查歌曲数据集合
for(int i=0;i"MUSIC",""+musics.get(i));
}
adapter = new MusicAdapter(MainActivity.this,musics);
listView.setAdapter(adapter);
}
//获取sd卡下的文件
private void getData(){
//【目标】扫描sd卡下的Music文件夹,获取所有歌曲信息
//1、获取sdcard下的Music文件夹的File对象
//2、检查Music文件夹是否存在
//3、获取Music文件夹下的文件列表
//4、检查文件列表是否有效
//5、遍历文件列表
//5.1、检查是否是文件
//5.2、检查是否是mp3文件
//String musicPath = "/storage/emulated/0/Music/";
//File musicDir = new File(musicPath);
if(Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
File musicDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC);
if (musicDir.exists()) {
Log.d("MUSIC", "【信息】文件夹存在");
File[] files = musicDir.listFiles();
if (files != null && files.length > 0) {
Log.d("MUSIC", "【信息】文件夹列表有效");
for (int i = 0; i < files.length; i++) {
if (files[i].isFile()) {
String fileName = files[i].getName();
if (fileName.toLowerCase().endsWith(".mp3")) {
Music music = new Music();
music.setPath(files[i].getAbsolutePath());
music.setTitle(files[i].getName());
musics.add(music);
Log.d("MUSIC", files[i].getAbsolutePath());
} else {
Log.w("MUSIC", "【错误】当前遍历到的不是mp3文件");
}
} else {
Log.w("MUSIC", "【错误】当前遍历到的第" + i + "个不是文件");
}
}
} else {
Log.w("MUSIC", "【错误】文件夹列表无效");
}
} else {
Log.w("MUSIC", "【错误】文件夹不存在");
}
}else{
Log.w("MUSIC", "【错误】SDCARD不可用");
}
}
//按钮监听
private class InnerClassOnClickListener implements View.OnClickListener{
@Override
public void onClick(View view) {
switch (view.getId()){
case R.id.ib_previous:
previous();
break;
case R.id.ib_play:
if(mediaPlayer.isPlaying()){
pause();
}else {
play();
}
break;
case R.id.ib_next:
next();
break;
}
}
}
//listview监听
private class OnItemClickListener implements AdapterView.OnItemClickListener{
@Override
public void onItemClick(AdapterView adapterView, View view, int i, long l) {
play(i);
}
}
//播放
private void play(){
try {
mediaPlayer.reset();
mediaPlayer.setDataSource(musics.get(currentMusicIndex).getPath());
mediaPlayer.prepare();
mediaPlayer.seekTo(pausePosition);
mediaPlayer.start();
ibPlay.setImageResource(android.R.drawable.ic_media_pause);
tvCurrentMusicTitle.setText("当前歌曲："+musics.get(currentMusicIndex).getTitle());
} catch (IOException e) {
e.printStackTrace();
}
}
//方法重载
private void play(int position){
currentMusicIndex = position;
pausePosition = 0;
play();
}
//暂停
private void pause(){
pausePosition = mediaPlayer.getCurrentPosition();
mediaPlayer.pause();
ibPlay.setImageResource(android.R.drawable.ic_media_play);
}
//下一首
private void next(){
currentMusicIndex++;
if(currentMusicIndex>musics.size()-1){
currentMusicIndex = 0;
}
//清空暂停时间
pausePosition = 0;
play();
}
//下一首
private void previous(){
currentMusicIndex--;
if(currentMusicIndex<0){
currentMusicIndex = musics.size()-1;
}
//清空暂停时间
pausePosition = 0;
play();
}
}
MusicAdapter
public class MusicAdapter extends BaseAdapter {
private List data;
private Context context;
public MusicAdapter(Context context,List data) {
this.context = context;
this.data = data;
}
@Override
public int getCount() {
return data.size();
}
@Override
public View getView(int i, View view, ViewGroup viewGroup) {
Music music = data.get(i);
if(view == null){
LayoutInflater inflater = LayoutInflater.from(context);
view = inflater.inflate(R.layout.item_music,null);
}
String fileName = music.getTitle();
TextView tv_music_path = view.findViewById(R.id.tv_music_path);
TextView tv_music_title = view.findViewById(R.id.tv_music_title);
tv_music_path.setText(music.getPath());
tv_music_title.setText(fileName.substring(0,fileName.lastIndexOf(".")));
return view;
}
@Override
public Object getItem(int i) {
return null;
}
@Override
public long getItemId(int i) {
return 0;
}
}
Music
public class Music {
private String path;
private String title;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
@Override
public String toString() {
return "Music Title ["+title+"] Music Path ["+path+"]";
}
}