android viewpager动态加载图片,Android使用ViewPager加载图片和轮播视频

宋慈面前耍柳叶刀

于 2021-05-26 22:49:45 发布

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文章标签： android viewpager动态加载图片

作为Android基础组件之一，大家对viewpager已经很熟悉了，网上也有很多使用viewpager来加载图片的案例。但是像微信那样点击图片，可以轮播显示图片和视频的例子却没找到。正巧项目中有需求，可以就花时间写了下，现在给一下核心代码，希望对有此需求的同学们起一个抛砖引玉的作用。话不多说了，上代码：

以下是initData的代码

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","=" + 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 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);

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 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);

}

我觉得轮播视频的难点在于viewpager只能播放一个视频，而每个viewItem都有继承自SurfaceView的SurfaceVideoView控件，我让原先页面的SurfaceViedeoView停止播放，并把新页面的SurfaceVideoView付给mVideoView，然后就可以对选中页面的视频进行控制了。

下面来张效果图：