Items of RecyclerView are not showing correctly

Question

In my onBindViewHolder of my RecyclerView.Adapter<SearchAdapter.ViewHolder> when user clicks on cardview a button becomes visible. But when I'm scrolling recyclerview some other items buttons are shown as visible too. Why is this happening?

this is my code:

@Override
public void onBindViewHolder(final ViewHolder viewHolder, final int position) {
    viewHolder.card.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (viewHolder.content_layout.getVisibility() == View.VISIBLE) {
                viewHolder.content_layout.setVisibility(View.GONE);
                viewHolder.address.setMaxLines(2);
                viewHolder.attribute.setMaxLines(2);
            } else {
                viewHolder.content_layout.setVisibility(View.VISIBLE);
                viewHolder.address.setMaxLines(8);
                viewHolder.attribute.setMaxLines(8);
            }
        }
    });
    ...
}

Answer 1

Once you start scrolling down the list your views get recycled. This means a previously inflated ViewHolder (some that gets created in onCreateViewHolder) is reused.
So what you have to do is to remember the clicked positions (e.g. via a SparseBooleanArray) and check in onBindViewHolder whether the view should be visible (previously clicked) or not.

You can find a basic usage example of the SparseBooleanArray in this StackOverflow post