使用RecyclerView搭配StaggeredGridLayoutManager实现瀑布流时,一般会在Adapter的onBindViewHolder()方法里给每一个item随机生成一个高度,使得item的排布错落有致,不死板。
@Override
public void onBindViewHolder(final ViewHolder holder, int position) {
//存在记录的高度时先Layout再异步加载图片
if (mList.get(holder.getAdapterPosition()).getHeight() > 0) {
ViewGroup.LayoutParams layoutParams = holder.ivGirl.getLayoutParams();
layoutParams.height = mList.get(holder.getAdapterPosition()).getHeight();
}
Glide.with(mContext).load(mList.get(position).getUrl()).asBitmap().diskCacheStrategy(DiskCacheStrategy.ALL)
.into(new SimpleTarget<Bitmap>(App.SCREEN_WIDTH / 2, App.SCREEN_WIDTH / 2) {
@Override
public void onResourceReady(Bitmap resource, GlideAnimation<? super Bitmap> glideAnimation) {
if(holder.getAdapterPosition() != RecyclerView.NO_POSITION) {
if (mList.get(holder.getAdapterPosition()).getHeight() <= 0) {
int width = resource.getWidth();
int height = resource.getHeight();
int realHeight = (App.SCREEN_WIDTH / 2) * height / width;
mList.get(holder.getAdapterPosition()).setHeight(realHeight);
ViewGroup.LayoutParams lp = holder.ivGirl.getLayoutParams();
lp.height = realHeight;
}
holder.ivGirl.setImageBitmap(resource);
}
}
});
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(onItemClickListener != null) {
View shareView = view.findViewById(R.id.iv_girl);
onItemClickListener.onItemClickListener(holder.getAdapterPosition(),shareView);
}
}
});
}
mAdapter = new GirlAdapter(mContext, mList);
mStaggeredGridLayoutManager = new StaggeredGridLayoutManager(SPAN_COUNT,StaggeredGridLayoutManager.VERTICAL);
rvGirlContent.setLayoutManager(mStaggeredGridLayoutManager);
rvGirlContent.setAdapter(mAdapter);
在StaggeredGridLayoutManager瀑布流中,当需要依据图片实际相对高度,不断动态设置ImageView的LayoutParams时,
会导致快速滑动状态下产生重新排列,重写getItemViewType并设置StaggeredGridLayoutManager.GAP_HANDLING_NONE解决了这个问题,原因目前未知
@Override
public int getItemViewType(int position) {
return Math.round((float) App.SCREEN_WIDTH / (float) mList.get(position).getHeight() * 10f);
}
mStaggeredGridLayoutManager.setGapStrategy(StaggeredGridLayoutManager.GAP_HANDLING_NONE);
效果如下: