playaudiotest

学习目的:1.播放音频 暂停音频 停止音频(MediaPlayer类的使用)

权限声明

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

MainActivity类
`java
public class MainActivity extends AppCompatActivity implements View.OnClickListener{

private MediaPlayer mediaPlayer = new MediaPlayer();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button play = (Button) findViewById(R.id.play);
    Button pause = (Button) findViewById(R.id.pause);
    Button stop = (Button) findViewById(R.id.stop);
    play.setOnClickListener(this);
    pause.setOnClickListener(this);
    stop.setOnClickListener(this);
    if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(MainActivity.this, new String[]{ Manifest.permission. WRITE_EXTERNAL_STORAGE }, 1);
    } else {
        initMediaPlayer(); // 初始化MediaPlayer
    }
}

private void initMediaPlayer() {
    try {
        File file = new File(Environment.getExternalStorageDirectory(), "music.mp3");
        mediaPlayer.setDataSource(file.getPath()); // 指定音频文件的路径
        mediaPlayer.prepare(); // 让MediaPlayer进入到准备状态
    } catch (Exception e) {
        e.printStackTrace();
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case 1:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                initMediaPlayer();
            } else {
                Toast.makeText(this, "拒绝权限将无法使用程序", Toast.LENGTH_SHORT).show();
                finish();
            }
            break;
        default:
    }
}

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.play:
            if (!mediaPlayer.isPlaying()) {
                mediaPlayer.start(); // 开始播放
            }
            break;
        case R.id.pause:
            if (mediaPlayer.isPlaying()) {
                mediaPlayer.pause(); // 暂停播放
            }
            break;
        case R.id.stop:
            if (mediaPlayer.isPlaying()) {
                mediaPlayer.reset(); // 停止播放
                initMediaPlayer();
            }
            break;
        default:
            break;
    }
}

@Override
protected void onDestroy() {
    super.onDestroy();
    if (mediaPlayer != null) {
        mediaPlayer.stop();
        mediaPlayer.release();
    }
}

}