视频播放器
SurfaceView  SurfaceView里面维护了两个缓冲区，一个准备数据，一个显示到界面上。 由于SurfaceView是个很耗资源的，所以当按home视频界面不可见时，surface holder被销毁， 当再次可见时，会重新创建一个holder对象，原来的holder对象已经销毁，所以黑屏 1、画面显示在哪里 mediaPlayer.setDisplay(sh); 2、异步准备，并监听准备完成的状态 mediaPlayer.prepareAsync();
mediaPlayer.setOnPreparedListener(new OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
mediaPlayer.start();
}
});3、为SurfaceHolder增加回调函数,关心surfaceview holder的存活周期 sv.getHolder().addCallback(new Callback() {
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
if (mediaPlayer != null && mediaPlayer.isPlaying()) {
currentPosition = mediaPlayer.getCurrentPosition();
mediaPlayer.stop();
mediaPlayer.release();
mediaPlayer = null;
}
System.out.println("holder 销毁了。。。播放位置：" + currentPosition);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
System.out.println("holder 创建了。。。");
if (currentPosition > 0) {
try {
String videoPath = et_path.getText().toString().trim();
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource(getApplicationContext(),Uri.parse(videoPath));
mediaPlayer.setDisplay(sv.getHolder());
mediaPlayer.prepareAsync();
mediaPlayer.setOnPreparedListener(new OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
System.out.println("从"+currentPosition+"位置开始播放");
mediaPlayer.seekTo(currentPosition);
mediaPlayer.start();
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
System.out.println("holder 变化了。。。");
}
});4、android4.0以下要加上，4.0后废弃了，告诉surfaceview 不要自己维护缓冲区 而是 等待多媒体播放器的框架 把数据填充过来 sv.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 5、2.3 2.2模拟器有bug,播放不了视频， 需要用1.6模拟器或者真机 |
| 核心代码： package cn.zengfansheng.videoplay; import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnPreparedListener;
import android.net.Uri;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends Activity { private EditText et_path;
private Button bt_pause;
private SurfaceView sv;
private MediaPlayer mediaPlayer;
private int currentPosition;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_path = (EditText) this.findViewById(R.id.et_path);
bt_pause = (Button) this.findViewById(R.id.bt_pause); sv = (SurfaceView) this.findViewById(R.id.sv); // android4.0以下要加上，4.0后废弃了，告诉surfaceview 不要自己维护缓冲区 而是 等待多媒体播放器的框架 把数据填充过来
sv.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
// 2.3 2.2模拟器有bug,播放不了视频， 需要用1.6模拟器或者真机 // TODO c、为SurfaceHolder增加回调函数,//关心surfaceview holder的存活周期
sv.getHolder().addCallback(new Callback() {
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
if (mediaPlayer != null && mediaPlayer.isPlaying()) {
currentPosition = mediaPlayer.getCurrentPosition();
mediaPlayer.stop();
mediaPlayer.release();
mediaPlayer = null;
}
System.out.println("holder 销毁了。。。播放位置：" + currentPosition);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
System.out.println("holder 创建了。。。");
if (currentPosition > 0) {
try {
String videoPath = et_path.getText().toString().trim();
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource(getApplicationContext(),Uri.parse(videoPath));
mediaPlayer.setDisplay(sv.getHolder());
mediaPlayer.prepareAsync();
mediaPlayer.setOnPreparedListener(new OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
System.out.println("从"+currentPosition+"位置开始播放");
mediaPlayer.seekTo(currentPosition);
mediaPlayer.start();
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
System.out.println("holder 变化了。。。");
}
});
}
/**
* TODO 1、开始播放视频
*
* @param view
*/
public void start(View view) {
try {
String videoPath = et_path.getText().toString().trim();
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource(getApplicationContext(), Uri.parse(videoPath));
mediaPlayer.setLooping(true);// 循环播放
// TODO b、SurfaceHolder//画面显示在哪里
SurfaceHolder sh = sv.getHolder();
mediaPlayer.setDisplay(sh);
// TODO a、prepareAsync()
mediaPlayer.prepareAsync();
mediaPlayer.setOnPreparedListener(new OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
mediaPlayer.start();
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* TODO 2、暂停播放视频
*
* @param view
*/
public void pause(View view) {
if ("续播".equals(bt_pause.getText().toString().trim()) && mediaPlayer!=null) {
mediaPlayer.start();
bt_pause.setText("暂停");
return;
}
if (mediaPlayer != null && mediaPlayer.isPlaying()) {
mediaPlayer.pause();
bt_pause.setText("续播");
}
}
/**
* TODO 3、停止播放视频
*
* @param view
*/
public void stop(View view) {
if (mediaPlayer != null && mediaPlayer.isPlaying()) {
mediaPlayer.stop();
mediaPlayer.release();
mediaPlayer = null;
}
}
/**
* TODO 4、重新播放视频
*
* @param view
*/
public void replay(View view) {
if (mediaPlayer != null && mediaPlayer.isPlaying())
mediaPlayer.seekTo(0); start(view);
}
} |
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| 问题1：播放过程中，按下Home，视频界面不可见，有声音，再次回到该视频界面，没有画面。 原因：由于SurfaceView是个很耗资源的，所以当按home视频界面不可见时， SurfaceHolder 被销毁，当再次可见时，会重新创建一个holder对象，原来的holder对象已经销毁，所以黑屏  |