How to create a ReyclerView which has extra CardView for adding new items-CodePudding

Consider an ArrayList which contains 4 element. The RecylcerView shows 4 CardViews. I know how to do that. For this particular RecyclerView, I want a different behaviour: there's a 5th cardview for adding new items. After new item is succesfully added to the ArrayList, then the "add item" CardView will be the 6th, etc.

Here's what I already have:

override fun getItemViewType(position: Int): Int {
    if (position < itemCount) return VIEW_DISPLAY_ITEM
    else return VIEW_ADD_ITEM
}

 override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) : RecyclerView.ViewHolder{
        if (viewType == VIEW_DISPLAY_ITEM){
            return ViewHolderDisplayItem(
                LayoutInflater.from(context).inflate(R.layout.display_item, parent, false)
            )
        }
        else {
            return ViewHolderAddItem(
                LayoutInflater.from(context).inflate(R.layout.add_new_item, parent, false)
            )
        }
    }


override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        when (holder.itemViewType){
            VIEW_DISPLAY_ITEM -> {
                (holder as ViewHolderDisplayItem).bind(position)
                holder.itemView.setOnClickListener {
                    val theData = theList.get(position)
                    txtItemName.text = theData.name
                    txtItemID.text = theData.id
                    txtItemLocation.text = theData.location
                }
            }

            VIEW_ADD_ITEM -> {
                (holder as ViewHolderAddItem).bind(position)
                holder.itemView.setOnClickListener {
                    
                }
            }
        }
    }

The result is not what I expected. The "add new item" cardview is not shown. I guess that's because when getItemType() is invoked, position is always lesser than itemCount.

No idea what's the simple solution for this. Hint/sample code is appreciated.

CodePudding user response：

Not included in your question is the code for getItemCount(). Make sure you are returning list.size 1 in order to include that final "add new item" element.

CodePudding user response：

You try

override fun getItemViewType(position: Int): Int {
    if (position <= itemCount) return VIEW_DISPLAY_ITEM
     else return VIEW_ADD_ITEM       }

I think you have a little misunderstanding in overriding the getItemViewType() function, position start from 0.

Hope it

CodePudding user response：

If u need simple solution
you can just use this CardView outside the recycler view but make sure that recycler view is wrap content so that it can be expandable

ScrollView >> LinearLayout >> RecyclerView >> CardView

Just like that

<androidx.recyclerview.widget.RecyclerView
        android:id="@ id/course_names_rv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:nestedScrollingEnabled="false"/>

So u can easily add new item to your adapter without using view types or something else

I’ve already made it and it works fine with me