Adding ImageViews to RecyclerView Item Layouts

Question

I have a RecyclerView with items, which sometimes should show sometimes up to three icons. At the moment I am just adding ImageViews to the layout in the onBind metod dynamically, but sometimes the ImageViews are added to the wrong item. I have read some other questions with Problems on loading images too, what's the best approach to do this?

Answer 1

Define three ImageVies in your custom_row.xml or whatever you named it. Set the width on wrap content and the gravitiy on center_horizontal so it will shown nicely. In your onBindViewHolder(ItemViewHolder ivHolder, int position) you have to do the following: Dependent on the current position you set 1,2 or 3 of the imageview-visibilities on GONE OR VISIBLE. So the Images will always be centered in the horizontal. Then you fill the imageviews with images. I think thats it. It worked for me.

Dont forget to define the 3 Imageviews in your ItemViewHolder constructor.

Answer 2

ViewHolder can be recycled from an another position, thus if you add views in the onBindViewHolder it needs adding or removing (if exist) them on position's dependency.

Answer 3

this is a common issues as you need to sync access to the holder. There are a few quite good libraries to handle this and other cases of bitmap caching, reusing, pooling.

you can use glide for local and network images:

   Glide.with(context).load(items.get(i).getImage()).into(viewHolder.image);

or for only network images Volley or jus swithing to their NetworkImageView widget and then in the adapter:

image.setImageUrl(items.get(i).getImage(), imageLoader);

These may use different approaches but they all know what to do.