Question

我在ActionBar中创建了一个MediaPlayer按钮，当应用程序启动时它会自动播放，当我点击它时它应该关闭。现在的问题是声音没有播放，当我点击按钮时，logcat中有一个错误说...

更新的LOGCAT。

12-18 19:04:57.812: E/MediaPlayer(5673): attachNewPlayer called in state 32

这是代码..

public class MainActivity extends Activity{

private MediaPlayer mp;
Item btnplay;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mp = new MediaPlayer();
mp.setOnCompletionListener(new OnCompletionListener() {

@Override
public void onCompletion(MediaPlayer arg0) {
    // TODO Auto-generated method stub
    isPlaying=false;//when the media file playing is completed isPlaying=false; is must
}
});
play(null);//you are calling play by launching
}

//inflate items in actionbar
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}

boolean isPlaying = false;
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// toggle nav drawer on selecting action bar app icon/title
if (mDrawerToggle.onOptionsItemSelected(item)) {
    return true;
}
    if (item.getItemId() == R.id.btnplay) //whatever you named in xml
    {
        play(item);
    }

    return super.onOptionsItemSelected(item);
    }

public void play(MenuItem menuItem) {

if (!isPlaying) {
try
{
    AssetFileDescriptor afd = getAssets().openFd("caketown.mp3"); 
    mp.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength()); 
    mp.prepare();
    mp.start();//play sound
}
catch(Exception e) {
e.printStackTrace();
}
isPlaying = true;
}
else if (isPlaying) {
mp.pause();
isPlaying = false;
}
}

这是菜单

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.xxx.MainActivity" >

<item
android:id="@+id/btnplay"
android:title=""
android:icon="@drawable/ic_action_volume_on"
android:onClick="play"
android:showAsAction="always"/>   
<menu>

请帮帮我。我刚来这里。：（

Answer 1

1.请在mp = new MediaPlayer();方法

中初始化onCreate()

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
    play(null);//you are calling play by launching
    }

2.将其更改为boolean isPlaying = false;，因为当应用启动时，它会设置为boolean isPlaying = false，因此它会播放音频并再次点击它暂停，它将按照您的代码运行

3.更改此else if

else if (isPlaying) {
mp.pause();
isPlaying=false;
}

4.也改变这个功能

public void play(MenuItem menuItem) {

        if (!isPlaying && !isPaused) {

        try {
            if (mp == null) {
                // mp.release();
                // mp.reset();
                mp = new MediaPlayer();
                AssetFileDescriptor afd = getAssets()
                        .openFd("caketown.mp3");
                mp.setDataSource(afd.getFileDescriptor(),
                        afd.getStartOffset(), afd.getLength());
                mp.prepare();

                mp.setOnCompletionListener(new OnCompletionListener() {

                    @Override
                    public void onCompletion(MediaPlayer arg0) {
                        // TODO Auto-generated method stub
                        isPlaying = false;// when the media file playing is completed
                        isPaused = false;
                        // Toast.makeText(getApplicationContext(), "play completed",
                        // Toast.LENGTH_SHORT).show(); // isPlaying=false; is must
                    }
                });
            }
            mp.start();// play sound
        } catch (Exception e) {
            e.printStackTrace();
        }
        isPlaying = true;

        } else if (isPlaying) {
            Toast.makeText(getApplicationContext(), "play paused",
                    Toast.LENGTH_SHORT).show();
            mp.pause();
            isPlaying = false;
            isPaused = true;
            length = mp.getCurrentPosition();
            // and for resuming the player from the position where it stopped
            // lately is done by:

        } else if (isPaused) {
            mp.seekTo(length);
            mp.start();
            isPlaying = true;
            isPaused = false;
        }
    }

Answer 2

将isPlaying初始化为false以使您的条件有效。
仅初始化MediaPlayer一次以使停止/暂停工作而不是重叠声音。也就是说，例如将mp = new MediaPlayer();移至onCreate()。

Mediaplayer：在状态1中调用暂停 - Android Eclipse

2 个答案: