public class ReleaseMessageActivity extends AppCompatActivity {
 
 @BindView(R.id.text_cancel)
 TextView textCancel;
 @BindView(R.id.text_release)
 TextView textRelease;
 @BindView(R.id.mRec)
 RecyclerView mRec;
 @BindView(R.id.et_messsage)
 EditText etMesssage;
 private ArrayList<String> listImagePath;
 private ArrayList<String> mList = new ArrayList<>();
 private ReleaseMsgAdapter adapter;
 
 private ArrayList<String> list = new ArrayList<String>();
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_release_message);
  ButterKnife.bind(this);
  setRecyclerview();
 }
 
 private void setRecyclerview() {
  if (mList != null) {
   GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 4);
   mRec.setLayoutManager(gridLayoutManager);
   adapter = new ReleaseMsgAdapter(ReleaseMessageActivity.this, mList);
   mRec.setAdapter(adapter);
  }
 
 }
 
 @OnClick({R.id.text_cancel, R.id.text_release})
 public void onClick(View view) {
  switch (view.getId()) {
   case R.id.text_cancel:
    ToastUtil.showToast("取消");
    break;
   case R.id.text_release:
    ToastUtil.showToast("发布");
    break;
  }
 }
 //用户选中图片后，拿到回掉结果
 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);
  if (requestCode == 0 && resultCode == RESULT_OK) {
   listImagePath = data.getStringArrayListExtra(EXTRA_RESULT);
   compress(listImagePath);
  }
 }
//压缩 拿到返回选中图片的集合url，然后转换成file文件
 public void compress(ArrayList<String> list) {
  for (String imageUrl : list) {
   LogUtils.e(">>>>>>", imageUrl);
   File file = new File(imageUrl);
   compressImage(file);
  }
  adapter.addMoreItem(list);
 }
//压缩
 private void compressImage(File file) {
  Luban.get(this)//用的第三方的压缩，开源库 Luban 大家可以自行百度
    .load(file)      //传人要压缩的图片
    .putGear(Luban.THIRD_GEAR)  //设定压缩档次，默认三挡
    .setCompressListener(new OnCompressListener() { //设置回调
     @Override
     public void onStart() {
      //TODO 压缩开始前调用，可以在方法内启动 loading UI
     }
 
     @Override
     public void onSuccess(final File file) {
      URI uri = file.toURI();
      String[] split = uri.toString().split(":");
      list.add(split[1]);//压缩后返回的文件，带file字样，所以需要截取
      LogUtils.e(BaseApplication.TAG, uri + "????????????" + split[1]);
     }
 
     @Override
     public void onError(Throwable e) {
      //TODO 当压缩过去出现问题时调用
     }
    }).launch();//启动压缩
 }
}

public class ReleaseMsgAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
 private Activity context;
 private ArrayList<String> mList;
 private final LayoutInflater inflater;
 private static final int ITEM_TYPE_ONE = 0x00001;
 private static final int ITEM_TYPE_TWO = 0x00002;
 /**
 *这里之所以用多行视图，因为我们默认的有一张图片的（那个带+的图片，用户点击它才会才会让你去选择图片）
 *集合url为空的时候，默认显示它，当它达到集合9时，这个图片会自动隐藏。
 */
 public ReleaseMsgAdapter(Activity context, ArrayList<String> mList) {
  this.context = context;
  this.mList = mList;
  inflater = LayoutInflater.from(context);
 }
 
 @Override
 public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
  parent.setPadding(20, 0, 20, 0);
  switch (viewType) {
   case ITEM_TYPE_ONE:
    return new MyHolder(inflater.inflate(R.layout.release_message_item, parent, false));
   case ITEM_TYPE_TWO:
    return new MyTWOHolder(inflater.inflate(R.layout.release_message_two_item, parent, false));
   default:
    return null;
  }
 }
 
 @Override
 public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
  if (holder instanceof MyHolder) {
   bindItemMyHolder((MyHolder) holder, position);
  } else if (holder instanceof MyTWOHolder) {
   bindItemTWOMyHolder((MyTWOHolder) holder, position);
  }
 }
 
 private void bindItemTWOMyHolder(final MyTWOHolder holder, int position) {
  LogUtils.e("Adapter", listSize() + "");
  if (listSize() >= 9) {//集合长度大于等于9张时，隐藏 图片
   holder.imageview2.setVisibility(View.GONE);
  }
  holder.imageview2.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View v) {
   //选择图片
    CommonUtil.uploadPictures(context, 9 - listSize(), 0);
   }
  });
 }
 
 private void bindItemMyHolder(MyHolder holder, int position) {
  Glide.with(context)
    .load(mList.get(position))
    .centerCrop()
    .into(holder.imageview);
 }
 
 @Override
 public int getItemViewType(int position) {
  if (position + 1 == getItemCount()) {
   return ITEM_TYPE_TWO;
  } else {
   return ITEM_TYPE_ONE;
  }
 }
 
 @Override
 public int getItemCount() {
  LogUtils.e("getItemCount", mList.size() + 1 + "");
  return mList.size() + 1;
 }
 
 class MyHolder extends RecyclerView.ViewHolder {
  private final ImageView imageview;
  public MyHolder(View itemView) {
   super(itemView);
   imageview = (ImageView) itemView.findViewById(R.id.imageview);
  }
 }
 
 class MyTWOHolder extends RecyclerView.ViewHolder {
  private final ImageView imageview2;
  public MyTWOHolder(View itemView) {
   super(itemView);
   imageview2 = (ImageView) itemView.findViewById(R.id.imageview2);
  }
 }
 //对外暴露方法 。点击添加图片（类似于上啦加载数据）
  public void addMoreItem(ArrayList<String> loarMoreDatas) {
  mList.addAll(loarMoreDatas);
  notifyDataSetChanged();
 }
//得到集合长度
 public int listSize() {
  int size = mList.size();
  return size;
 }
}