Question

我正在设计一个从头开始的媒体播放器，所以我陷入困境的是当歌曲播放完毕后我想将搜索栏设置为初始值我知道这可以用

完成

seekBar.setProgress（0）但这对我不起作用，我希望播放按钮切换回暂停按钮，如果用户再次播放歌曲，则歌曲将正常播放这是我的媒体播放器代码，希望你告诉我逻辑是什么以及如何放置它

public class MusicPlayerActivity extends AppCompatActivity implements Runnable,
        SeekBar.OnSeekBarChangeListener {
ImageView playpause;
SeekBar seekBar;
MediaPlayer mp = null;
int len = 0;
boolean isPlaying = false;


public MusicPlayerActivity() throws IOException {
}


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_music_player);
    String url = getIntent().getExtras().getString("musicurl");
    playpause = (ImageView)findViewById(R.id.imageView);
    seekBar = (SeekBar)findViewById(R.id.seekBar);
    playpause.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            if(!isPlaying){
                playpause.setImageResource(R.drawable.pause);
                mp.pause();
                len = mp.getCurrentPosition();
                seekBar.setEnabled(false);


            }else{
                playpause.setImageResource(R.drawable.play);
                mp.seekTo(len);
                mp.start();
                seekBar.setEnabled(true);

            }
            isPlaying = !isPlaying;



        }
    });

    mp = new MediaPlayer();
    try {
        mp.setDataSource(url);
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        mp.prepare();
    } catch (IOException e) {
        e.printStackTrace();
    }
    //if(mp.isPlaying()) mp.stop(); mp.release();
    mp.start();
    seekBar.setMax(mp.getDuration());
    new Thread(this).start();
   // Toast.makeText(this, mp.getDuration(), Toast.LENGTH_SHORT).show();


}

//if(mp.isPlaying()){}
@Override
public void onProgressChanged(SeekBar seekBar, int progress,
                              boolean fromUser) {
    try {
        if (mp.isPlaying() || mp != null) {
            if (fromUser)
                mp.seekTo(progress);
        } else if (mp == null) {
            Toast.makeText(getApplicationContext(), "Media is not running",
                    Toast.LENGTH_SHORT).show();
            seekBar.setProgress(0);
        }
    } catch (Exception e) {
        Log.e("seek bar", "" + e);
        seekBar.setEnabled(false);

    }
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {

}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {

}

public void run() {
    int currentPosition = mp.getCurrentPosition();
    int total = mp.getDuration();

    while (mp != null && currentPosition < total) {
        try {
            Thread.sleep(1000);
            currentPosition = mp.getCurrentPosition();
        } catch (InterruptedException e) {
            return;
        } catch (Exception e) {
            return;
        }
        seekBar.setProgress(currentPosition);
    }
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            mp.stop();
            startActivity(new Intent(this,MainActivity.class));
            break;
    }
    return true;
}
@Override
public void onBackPressed() {
    Intent mainActivity = new Intent(Intent.ACTION_MAIN);
    mainActivity.addCategory(Intent.CATEGORY_HOME);
    mainActivity.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(mainActivity);
}

}

Answer 1

在seekbar.setOnSeekBarChangeListener(this);中添加onCreate，否则不会调用onProgressChanged()。

要重置进度条，请查看以下方法：

在媒体播放器实例上设置OnCompletionListener。媒体文件完成播放后，您可以在OnCompletion(MediaPlayer mp)回调函数中执行所需的操作。

在mp.start()之前添加以下代码段应该适合您。

mp.setOnCompletionListener(new OnCompletionListener() {

            @Override
            public void onCompletion(MediaPlayer mp) {
                seekBar.setProgress(0); // sets seekbar to initial position.
                toggleViews();//implement this function to toggle your play/pause button

            }

        });

Answer 2

您没有设置监听器：seekbar.setOnSeekBarChangeListener(this)

android将搜索栏设置为初始并切换播放按钮以在音乐结束时暂停

2 个答案: