我试图使用MediaController.MediaPlayerControl以便在“自定义 View ”的底部显示MediaController，但无法正常工作。每当我尝试加载此 View 时，它都会在ctrl.show();处崩溃并显示以下异常:
这是我的代码。
public class MediaPlayerView extends ImageView implements MediaPlayerControl {
private MediaPlayer mp;
private MediaController ctrl;
private Uri data;
private Context mContext;
public MediaPlayerView(Context context, Uri data) {
super(context);
this.mContext = context;
this.data = data;
init();
}
public void init() {
mp = new MediaPlayer();
try {
mp.setDataSource(mContext, data);
mp.prepare();
} catch(IOException e) {
e.printStackTrace();
}
ctrl = new MediaController(mContext);
ctrl.setMediaPlayer(this);
ctrl.setAnchorView(this);
ctrl.setEnabled(true);
ctrl.show();
}
public boolean canPause() {
return true;
}
public boolean canSeekBackward() {
return false;
}
public boolean canSeekForward() {
return false;
}
public int getBufferPercentage() {
return (mp.getCurrentPosition()*100)/mp.getDuration();
}
public int getCurrentPosition() {
return mp.getCurrentPosition();
}
public int getDuration() {
return mp.getDuration();
}
public boolean isPlaying() {
return mp.isPlaying();
}
public void pause() {
mp.pause();
}
public void seekTo(int pos) {
mp.seekTo(pos);
}
public void start() {
mp.start();
}
}
任何帮助，不胜感激!
最佳答案
受到VideoView实现的启发package org.myvideo;import android.app.AlertDialog;import android.content.Context;import android.content.Intent;import android.media.AudioManager;import android.media.MediaPlayer;import android.media.MediaPlayer.OnPreparedListener;import android.media.MediaPlayer.OnCompletionListener;import android.media.MediaPlayer.OnErrorListener;import android.view.MotionEvent;import android.net.Uri;import android.util.Log;import android.view.View;import android.view.KeyEvent;import android.widget.ImageView;import android.widget.MediaController;import android.widget.MediaController.MediaPlayerControl;import android.util.AttributeSet;import android.content.DialogInterface;import android.content.DialogInterface.OnClickListener;import java.io.IOException;public class MyAudioView extends ImageView implements MediaPlayerControl { // settable by the client private Uri mUri; // All the stuff we need for playing and showing a video private MediaPlayer mMediaPlayer = null; private MediaController mMediaController; private int mCurrentBufferPercentage; private boolean mStartWhenPrepared; private int mSeekWhenPrepared; private Context mContext; private boolean mIsPrepared; private MediaPlayer.OnPreparedListener mOnPreparedListener; private OnErrorListener mOnErrorListener; private OnCompletionListener mOnCompletionListener; public MyAudioView(Context context) { super(context); mContext = context; } public MyAudioView(Context context, AttributeSet attrs) { this(context, attrs, 0); mContext = context; } public MyAudioView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); mContext = context; } public void setVideoPath(String path) { setAudioURI(Uri.parse(path)); } public void setAudioURI(Uri uri) { mUri = uri; mStartWhenPrepared = false; mSeekWhenPrepared = 0; openVideo(); requestLayout(); invalidate(); } public void stopPlayback() { if (mMediaPlayer != null) { mMediaPlayer.stop(); mMediaPlayer.release(); mMediaPlayer = null; } } private void openVideo() { if (mUri == null) { // not ready for playback just yet, will try again later return; } // Tell the music playback service to pause // TODO: these constants need to be published somewhere in the framework. Intent i = new Intent("com.android.music.musicservicecommand"); i.putExtra("command", "pause"); mContext.sendBroadcast(i); if (mMediaPlayer != null) { mMediaPlayer.reset(); mMediaPlayer.release(); mMediaPlayer = null; } try { mMediaPlayer = new MediaPlayer(); mMediaPlayer.setOnPreparedListener(mPreparedListener); mIsPrepared = false; mMediaPlayer.setOnCompletionListener(mCompletionListener); mMediaPlayer.setOnErrorListener(mErrorListener); mMediaPlayer.setOnBufferingUpdateListener(mBufferingUpdateListener); mCurrentBufferPercentage = 0; mMediaPlayer.setDataSource(mContext, mUri); mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); mMediaPlayer.setScreenOnWhilePlaying(true); mMediaPlayer.prepareAsync(); attachMediaController(); } catch (IOException ex) { Log.w("MyAudioView", "Unable to open content: " + mUri, ex); return; } catch (IllegalArgumentException ex) { Log.w("MyAudioView", "Unable to open content: " + mUri, ex); return; } } public void setMediaController(MediaController controller) { if (mMediaController != null) { mMediaController.hide(); } mMediaController = controller; attachMediaController(); } private void attachMediaController() { if (mMediaPlayer != null && mMediaController != null) { mMediaController.setMediaPlayer(this); View anchorView = this.getParent() instanceof View ? (View)this.getParent() : this; mMediaController.setAnchorView(anchorView); mMediaController.setEnabled(mIsPrepared); } } MediaPlayer.OnPreparedListener mPreparedListener = new MediaPlayer.OnPreparedListener() { public void onPrepared(MediaPlayer mp) { // briefly show the mediacontroller mIsPrepared = true; if (mOnPreparedListener != null) { mOnPreparedListener.onPrepared(mMediaPlayer); } if (mMediaController != null) { mMediaController.setEnabled(true); } if (mStartWhenPrepared) { mMediaPlayer.start(); } } }; private MediaPlayer.OnCompletionListener mCompletionListener = new MediaPlayer.OnCompletionListener() { public void onCompletion(MediaPlayer mp) { if (mMediaController != null) { mMediaController.hide(); } if (mOnCompletionListener != null) { mOnCompletionListener.onCompletion(mMediaPlayer); } } }; private MediaPlayer.OnErrorListener mErrorListener = new MediaPlayer.OnErrorListener() { public boolean onError(MediaPlayer mp, int a, int b) { Log.d("MyAudioView", "Error: " + a + "," + b); if (mMediaController != null) { mMediaController.hide(); } /* If an error handler has been supplied, use it and finish. */ if (mOnErrorListener != null) { if (mOnErrorListener.onError(mMediaPlayer, a, b)) { return true; } } /* Otherwise, pop up an error dialog so the user knows that * something bad has happened. Only try and pop up the dialog * if we're attached to a window. When we're going away and no * longer have a window, don't bother showing the user an error. */ if (getWindowToken() != null) { new AlertDialog.Builder(mContext) .setTitle("Error") .setMessage("This track could not be played") .setPositiveButton("OK", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { /* If we get here, there is no onError listener, so * at least inform them that the video is over. */ if (mOnCompletionListener != null) { mOnCompletionListener.onCompletion(mMediaPlayer); } } }) .setCancelable(false) .show(); } return true; } }; private MediaPlayer.OnBufferingUpdateListener mBufferingUpdateListener = new MediaPlayer.OnBufferingUpdateListener() { public void onBufferingUpdate(MediaPlayer mp, int percent) { mCurrentBufferPercentage = percent; } }; /** * Register a callback to be invoked when the media file * is loaded and ready to go. * * @param l The callback that will be run */ public void setOnPreparedListener(MediaPlayer.OnPreparedListener l) { mOnPreparedListener = l; } /** * Register a callback to be invoked when the end of a media file * has been reached during playback. * * @param l The callback that will be run */ public void setOnCompletionListener(OnCompletionListener l) { mOnCompletionListener = l; } @Override public boolean onTouchEvent(MotionEvent ev) { if (mIsPrepared && mMediaPlayer != null && mMediaController != null) { toggleMediaControlsVisiblity(); } return false; } @Override public boolean onTrackballEvent(MotionEvent ev) { if (mIsPrepared && mMediaPlayer != null && mMediaController != null) { toggleMediaControlsVisiblity(); } return false; } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if (mIsPrepared && keyCode != KeyEvent.KEYCODE_BACK && keyCode != KeyEvent.KEYCODE_VOLUME_UP && keyCode != KeyEvent.KEYCODE_VOLUME_DOWN && keyCode != KeyEvent.KEYCODE_MENU && keyCode != KeyEvent.KEYCODE_CALL && keyCode != KeyEvent.KEYCODE_ENDCALL && mMediaPlayer != null && mMediaController != null) { if (keyCode == KeyEvent.KEYCODE_HEADSETHOOK) { if (mMediaPlayer.isPlaying()) { pause(); mMediaController.show(); } else { start(); mMediaController.hide(); } return true; } else { toggleMediaControlsVisiblity(); } } return super.onKeyDown(keyCode, event); } private void toggleMediaControlsVisiblity() { if (mMediaController.isShowing()) { mMediaController.hide(); } else { mMediaController.show(); } } public void start() { if (mMediaPlayer != null && mIsPrepared) { mMediaPlayer.start(); mStartWhenPrepared = false; } else { mStartWhenPrepared = true; } } public void pause() { if (mMediaPlayer != null && mIsPrepared) { if (mMediaPlayer.isPlaying()) { mMediaPlayer.pause(); } } mStartWhenPrepared = false; } public int getDuration() { if (mMediaPlayer != null && mIsPrepared) { return mMediaPlayer.getDuration(); } return -1; } public int getCurrentPosition() { if (mMediaPlayer != null && mIsPrepared) { return mMediaPlayer.getCurrentPosition(); } return 0; } public void seekTo(int msec) { if (mMediaPlayer != null && mIsPrepared) { mMediaPlayer.seekTo(msec); } else { mSeekWhenPrepared = msec; } } public boolean isPlaying() { if (mMediaPlayer != null && mIsPrepared) { return mMediaPlayer.isPlaying(); } return false; } public int getBufferPercentage() { if (mMediaPlayer != null) { return mCurrentBufferPercentage; } return 0; } public boolean canSeekForward() { return true; } public boolean canSeekBackward() { return true; } public boolean canPause() { return true; }}package org.myvideo;import android.app.Activity;import android.os.Bundle;import android.widget.MediaController;import android.net.Uri;public class MyVideo extends Activity{ /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { MyAudioView video = new MyAudioView(this); video.setMediaController(new MediaController(this)); super.onCreate(savedInstanceState); video.setAudioURI(Uri.parse("http://url_to_media")); video.setImageResource(R.drawable.icon); setContentView(video); }}
关于android - 如何使用MediaController.MediaPlayerControl？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/3535949/