Android使用ViewPager加载图片和轮播视频

public void initData() {
 //把聊天界面的图片和视频找出来，并加到数组中，并在
 //并根据传进来的position来找到视频或图片在数组中的位置
 for (int i = 0; i < MsgCount; i++) {
  Msg1 msg1 = fridenMessages.MessageList.get(i);
  if (msg1.getMsg().startsWith(ChatUtil.TAG_IMAGE) || msg1.getMsg().startsWith(ChatUtil.TAG_VIDEO)) {
  ImageUrl.add(msg1.getMsg());
  //查看消息postion对应的图片位置
  if (position == i) {
   position = ImageUrl.size() - 1;
   Log.i("TAG", "position=" + position);
  }

  }
 }
 Log.i("TAG", "position=" + position);
 //把要用到的view加到viewList中
 for (int i = 0; i < ImageUrl.size(); i++) {
  if (ImageUrl.get(i).startsWith(ChatUtil.TAG_IMAGE)) {
  PhotoView photoView = new PhotoView(context);
  viewList.add(photoView);
  } else if (ImageUrl.get(i).startsWith(ChatUtil.TAG_VIDEO)) {


  View view1 = LayoutInflater.from(context).inflate(R.layout.activity_video_player, null);
  SurfaceVideoView videoView = (SurfaceVideoView) view1.findViewById(R.id.videoview);
  int screenWidth = getScreenWidth((Activity) context);
  int videoHight = (int) (screenWidth / (MediaRecorderBase.SMALL_VIDEO_WIDTH / (MediaRecorderBase.SMALL_VIDEO_HEIGHT * 1.0f)));
//  int videoHight = (int) (screenWidth)*4/3;
  videoView.getLayoutParams().height = videoHight;
  videoView.requestLayout();
  View playStatus = view1.findViewById(R.id.play_status);
  View loading = view1.findViewById(R.id.loading);
  viewList.add(view1);
  }
 }

 adapter = new MyAdapter();
 viewPager.setAdapter(adapter);
 if (position != -1) {
  viewPager.setCurrentItem(position);
 }
 }
``` public void initEvent() {
 //给viewPager设置监听
 viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

  @Override
  public void onPageSelected(int arg0) {

  int childCount = viewPager.getChildCount();//viewPager得到页面的数量
  //如果不是在原页面，让原来页面的视频停止播放
  if(position != arg0){
   position=arg0;
   StopVideo();
  }

  // 遍历当前所有加载过的PhotoView，恢复所有图片的默认状态

  for (int i = 0; i < childCount; i++) {
   View childAt = viewPager.getChildAt(i);

   try {
   if (childAt != null && childAt instanceof PhotoView) {
    PhotoView photoView = (PhotoView) childAt;
    photoView.setOnPhotoTapListener(new PhotoViewAttacher.OnPhotoTapListener() {
    @Override
    public void onPhotoTap(View view, float x, float y) {
     finish();
    }

    @Override
    public void onOutsidePhotoTap() {

    }
    });
   }
   } catch (Exception e) {
   e.printStackTrace();
   }
  }
  if (ImageUrl.get(position).startsWith(ChatUtil.TAG_VIDEO)) {
   String body = ChatApplication.dbHelper.getVideoSdPath(ImageUrl.get(position));
   String url[] = ImageUrl.get(position).substring(ChatUtil.TAG_VIDEO.length()).split("&&");
   View childAt = viewList.get(arg0);
   SurfaceVideoView videoView = (SurfaceVideoView) childAt.findViewById(R.id.videoview);
   mVideoView = videoView;
   mPlayerStatus = childAt.findViewById(R.id.play_status);
   mLoading = childAt.findViewById(R.id.loading);
   Log.i("TAG", "videoUrl=" + body);
   setVideoUrl(body, url);
   //延迟50ms，让播放器播放视频时，让它暂停
   Handler handler = new Handler();
   handler.postDelayed(new Runnable() {
   @Override
   public void run() {
    StopVideo();
   }
   }, 50);
  }
  }

  @Override
  public void onPageScrolled(int arg0, float arg1, int arg2) {
  // TODO Auto-generated method stub

  }

  @Override
  public void onPageScrollStateChanged(int arg0) {
  // TODO Auto-generated method stub

  }
 });
 }
 public class MyAdapter extends PagerAdapter {

 @Override
 public int getCount() {
  return ImageUrl.size();
 }

 @Override
 public View instantiateItem(ViewGroup container, int pos) {
  Log.i("TAG", "pos=" + pos);
  if (ImageUrl.get(pos).startsWith(ChatUtil.TAG_IMAGE)) {
  PhotoView photoView = (PhotoView) viewList.get(pos);
  container.addView(photoView, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
  String body[] = ImageUrl.get(pos).substring(ChatUtil.TAG_IMAGE.length()).split("&&");
  Log.i("TAG", "<IMAGE>=" + body[0]);
  ImageLoader.getInstance().displayImage(body[0], photoView);
  photoView.setScaleType(ImageView.ScaleType.FIT_CENTER);//设置图片显示为充满全屏
  photoView.setOnPhotoTapListener(new PhotoViewAttacher.OnPhotoTapListener() {
   @Override
   public void onPhotoTap(View view, float x, float y) {
   finish();
   }

   @Override
   public void onOutsidePhotoTap() {

   }
  });
  //  photoView.setOnLongClickListener(longClickListener);

  } else if (ImageUrl.get(pos).startsWith(ChatUtil.TAG_VIDEO)) {
   View view1 = viewList.get(pos);
  SurfaceVideoView VideoView = (SurfaceVideoView) view1.findViewById(R.id.videoview);
  int screenWidth = getScreenWidth((Activity) context);
  int videoHight = (int) (screenWidth / (MediaRecorderBase.SMALL_VIDEO_WIDTH / (MediaRecorderBase.SMALL_VIDEO_HEIGHT * 1.0f)));
//  int videoHight = (int) (screenWidth)*4/3;
  VideoView.getLayoutParams().height = videoHight;
  VideoView.requestLayout();
  View PlayerStatus = view1.findViewById(R.id.play_status);
  View Loading = view1.findViewById(R.id.loading);
  VideoView.setOnPreparedListener(ShowBigPictureActivity.this);
  VideoView.setOnPlayStateListener(ShowBigPictureActivity.this);
  VideoView.setOnErrorListener(ShowBigPictureActivity.this);
  VideoView.setOnClickListener(ShowBigPictureActivity.this);
  VideoView.setOnInfoListener(ShowBigPictureActivity.this);
  VideoView.setOnCompletionListener(ShowBigPictureActivity.this);
  container.addView(view1, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);

  String body = ChatApplication.dbHelper.getVideoSdPath(ImageUrl.get(pos));
  String url[] = ImageUrl.get(pos).substring(ChatUtil.TAG_VIDEO.length()).split("&&");
  //找到是点击聊天界面哪个视频进来的，将局部成员，付给类成员
  if(pos==position) {
   mVideoView = VideoView;
   mPlayerStatus=PlayerStatus;
   mLoading=Loading;
   setVideoUrl(body,url);

  }



  }

  return viewList.get(pos);
 }

 @Override
 public void destroyItem(ViewGroup container, int position, Object object) {
  container.removeView((View) object);
 }

 @Override
 public boolean isViewFromObject(View view, Object object) {
  return view == object;
 }
 }
以下是控制视频播放的接口：
 public void onCompletion(MediaPlayer mp) {
 onStateChanged(false);
 }

 @Override
 public boolean onError(MediaPlayer mp, int what, int extra) {

 return false;

 }

 @Override
 public boolean onInfo(MediaPlayer mp, int what, int extra) {
 switch (what) {
  case MediaPlayer.MEDIA_INFO_BAD_INTERLEAVING:
  // 音频和视频数据不正确
  ConfigUtil.showShort(context, "视频数据不正确！");
  break;
  case MediaPlayer.MEDIA_INFO_BUFFERING_START:
  if (!isFinishing())
   mVideoView.pause();
  break;
  case MediaPlayer.MEDIA_INFO_BUFFERING_END:
  if (!isFinishing())
   mVideoView.start();
  break;
  case MediaPlayer.MEDIA_INFO_VIDEO_RENDERING_START:
  if (DeviceUtils.hasJellyBean()) {
   mVideoView.setBackground(null);
  } else {
   mVideoView.setBackgroundDrawable(null);
  }
 break;
 }
 return false;
}

 @Override
 public void onStateChanged(boolean isPlaying) {
 mPlayerStatus.setVisibility(isPlaying ? View.GONE : View.VISIBLE);


 }

 @Override
 public void onPrepared(MediaPlayer mp) {
 mVideoView.setVolume(SurfaceVideoView.getSystemVolumn(this));
 mVideoView.start();
 mLoading.setVisibility(View.GONE);

 }