我有两个片段（左和右），并在左片段中获取 Radiostreams 列表。通过单击这些流之一，正确的片段应该更改流的名称并开始使用给定的 uri 播放流。
2 问题：
- 一些无线电流不是最新的，所以它们中的很多不再工作了。问题是，这会导致我的应用程序强制关闭！我做了错误处理，但在调用这样的流之后，我得到：
03-20 14:23:28.192: A/libc(1021): 致命信号 11 (SIGSEGV) 在 0x00000000 (code=1)
03-20 14:23:28.192: W/AudioSystem(1021): AudioFlinger 服务器死了！
03-20 14:23:28.192: W/IMediaDeathNotifier(1021): 媒体服务器死机
03-20 14:23:28.192: E/MediaPlayer(1021): 错误 (100, 0)
03-20 14:23:28.192: I/ServiceManager(1021): 等待服务 media.audio_flinger...
03-20 14:23:28.752: I/dalvikvm(1021): threadid=3: 对信号 3 做出反应
03-20 14:23:28.782: I/dalvikvm(1021): 将堆栈跟踪写入“/data/anr/traces.txt”
03-20 14:23:29.192: I/ServiceManager(1021): 等待服务 media.audio_flinger...
我不知道为什么。还有其他方法可以进行错误处理吗？或者有没有办法在调用 mediaPlayer.setDataSource(uri) 之前检查所有流以避免准备 defekt uris？（最后见我的代码）
- 我用遥控器控制左边的 ListFragment。当我尝试从一个频道快速切换到另一个频道时，一切都非常滞后。似乎 Mediaplayer 的重新实例化需要很长时间。当我不重新实例化时，当我再次调用 mediaPlayer.setDataSource(..) 时会出现运行时错误。有没有办法在一个 MediaPlayer 对象上调用 .setDataSource 两次？
这是我的代码：我的 MediaPlayer Wrapper 类：
package net.smart4life.tvplay.model;
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.AbstractCollection;
import java.util.ArrayList;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnBufferingUpdateListener;
import android.media.MediaPlayer.OnCompletionListener;
import android.media.MediaPlayer.OnErrorListener;
import android.media.MediaPlayer.OnInfoListener;
import android.media.MediaPlayer.OnPreparedListener;
import android.util.Log;
/**
* A wrapper class for {@link android.media.MediaPlayer}.
* <p>
* Encapsulates an instance of MediaPlayer, and makes a record of its internal
* state accessible via a {@link MediaPlayerWrapper#getState()} accessor.
*/
public class MediaPlayerStateWrapper {
private static String tag = "MediaPlayerWrapper";
private MediaPlayer mPlayer;
private State currentState;
private MediaPlayerStateWrapper mWrapper;
public MediaPlayerStateWrapper() {
mWrapper = this;
mPlayer = new MediaPlayer();
currentState = State.IDLE;
mPlayer.setOnPreparedListener(mOnPreparedListener);
mPlayer.setOnCompletionListener(mOnCompletionListener);
mPlayer.setOnBufferingUpdateListener(mOnBufferingUpdateListener);
mPlayer.setOnErrorListener(mOnErrorListener);
mPlayer.setOnInfoListener(mOnInfoListener);
}
/* METHOD WRAPPING FOR STATE CHANGES */
public static enum State {
IDLE, ERROR, INITIALIZED, PREPARING, PREPARED, STARTED, STOPPED, PLAYBACK_COMPLETE, PAUSED;
}
public void setDataSource(String path) {
if (currentState == State.IDLE) {
try {
mPlayer.setDataSource(path);
currentState = State.INITIALIZED;
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} else
throw new RuntimeException();
}
public void prepareAsync() {
Log.d(tag, "prepareAsync()");
if (EnumSet.of(State.INITIALIZED, State.STOPPED).contains(currentState)) {
mPlayer.prepareAsync();
currentState = State.PREPARING;
} else
throw new RuntimeException();
}
public boolean isPlaying() {
Log.d(tag, "isPlaying()");
if (currentState != State.ERROR) {
return mPlayer.isPlaying();
} else
throw new RuntimeException();
}
public void seekTo(int msec) {
Log.d(tag, "seekTo()");
if (EnumSet.of(State.PREPARED, State.STARTED, State.PAUSED,
State.PLAYBACK_COMPLETE).contains(currentState)) {
mPlayer.seekTo(msec);
} else
throw new RuntimeException();
}
public void pause() {
Log.d(tag, "pause()");
if (EnumSet.of(State.STARTED, State.PAUSED).contains(currentState)) {
mPlayer.pause();
currentState = State.PAUSED;
} else
throw new RuntimeException();
}
public void start() {
Log.d(tag, "start()");
if (EnumSet.of(State.PREPARED, State.STARTED, State.PAUSED,
State.PLAYBACK_COMPLETE).contains(currentState)) {
mPlayer.start();
currentState = State.STARTED;
} else
throw new RuntimeException();
}
public void stop() {
Log.d(tag, "stop()");
if (EnumSet.of(State.PREPARED, State.STARTED, State.STOPPED,
State.PAUSED, State.PLAYBACK_COMPLETE).contains(currentState)) {
mPlayer.stop();
currentState = State.STOPPED;
} else
throw new RuntimeException();
}
public void reset() {
Log.d(tag, "reset()");
mPlayer.reset();
currentState = State.IDLE;
}
/**
* @return The current state of the mediaplayer state machine.
*/
public State getState() {
Log.d(tag, "getState()");
return currentState;
}
public void release() {
Log.d(tag, "release()");
mPlayer.release();
}
/* INTERNAL LISTENERS */
private OnPreparedListener mOnPreparedListener = new OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
Log.d(tag, "on prepared");
currentState = State.PREPARED;
mWrapper.onPrepared(mp);
mPlayer.start();
currentState = State.STARTED;
}
};
private OnCompletionListener mOnCompletionListener = new OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
Log.d(tag, "on completion");
currentState = State.PLAYBACK_COMPLETE;
mWrapper.onCompletion(mp);
}
};
private OnBufferingUpdateListener mOnBufferingUpdateListener = new OnBufferingUpdateListener() {
@Override
public void onBufferingUpdate(MediaPlayer mp, int percent) {
Log.d(tag, "on buffering update");
mWrapper.onBufferingUpdate(mp, percent);
}
};
private OnErrorListener mOnErrorListener = new OnErrorListener() {
@Override
public boolean onError(MediaPlayer mp, int what, int extra) {
Log.d(tag, "on error");
currentState = State.ERROR;
mWrapper.onError(mp, what, extra);
return false;
}
};
private OnInfoListener mOnInfoListener = new OnInfoListener() {
@Override
public boolean onInfo(MediaPlayer mp, int what, int extra) {
Log.d(tag, "on info");
mWrapper.onInfo(mp, what, extra);
return false;
}
};
/* EXTERNAL STUBS TO OVERRIDE */
public void onPrepared(MediaPlayer mp) {
}
public void onCompletion(MediaPlayer mp) {
}
public void onBufferingUpdate(MediaPlayer mp, int percent) {
}
boolean onError(MediaPlayer mp, int what, int extra) {
// Error Handling of type: "MEdiaPlayer error(100,0)
mp.stop();
mp.release();
return false;
}
public boolean onInfo(MediaPlayer mp, int what, int extra) {
return false;
}
/* OTHER STUFF */
public int getCurrentPosition() {
if (currentState != State.ERROR) {
return mPlayer.getCurrentPosition();
} else {
return 0;
}
}
public int getDuration() {
// Prepared, Started, Paused, Stopped, PlaybackCompleted
if (EnumSet.of(State.PREPARED, State.STARTED, State.PAUSED,
State.STOPPED, State.PLAYBACK_COMPLETE).contains(currentState)) {
return mPlayer.getDuration();
} else {
return 100;
}
}
}
这是我的 TestFragment（右片段）。注意：左边的 Fragment 从 TestFragment 调用方法“newChannel(radioChannel)”，每次点击一个列表项。
package net.smart4life.tvplay.fragment;
import java.io.IOException;
import net.smart4life.tvplay.R;
import net.smart4life.tvplay.model.MediaPlayerStateWrapper;
import net.smart4life.tvplay.model.RadioChannel;
import android.app.Fragment;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnErrorListener;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
public class TestFragment extends Fragment {
private RadioChannel radioCh;
private TextView tv_RadioCh;
private MediaPlayerStateWrapper mediaWrapper;
private View view;
// firstcall
public TestFragment(RadioChannel radioChannel) {
this.radioCh = radioChannel;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onActivityCreated(savedInstanceState);
setRetainInstance(true);
tv_RadioCh = (TextView) view.findViewById(R.id.radioText);
mediaWrapper = new MediaPlayerStateWrapper();
newChannel(radioCh);
}
public void newChannel (RadioChannel radioChannel) {
this.radioCh = radioChannel;
Log.e("RadioChannel", radioCh.getName());
tv_RadioCh.setText(radioCh.getName());
if(mediaWrapper.isPlaying()) {
mediaWrapper.stop();
mediaWrapper.reset();
} else if(mediaWrapper.getState() == MediaPlayerStateWrapper.State.PREPARING) {
mediaWrapper.release();
mediaWrapper = new MediaPlayerStateWrapper();
}
mediaWrapper.setDataSource(radioCh.getUrl().toString());
mediaWrapper.prepareAsync();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_radio_player, container,
false);
return view;
}
@Override
public void onDetach() {
super.onDetach();
mediaWrapper.release();
}
}
专业人士，你能帮我解决一个或两个问题吗？