How to select all items which listed in recyclerview?

Question

I have list of items inside of recyclerview, and they are multiple selectable.

I want to have select button to select all, and if selected deselect all. I didn\'t se

Answer 1

There is no need to maintain another list with selected items. You need to create a method to set a flag and in the onBindViewHolder method just check for that flag. Something like this:

class MyAdapter(val context: Context): RecyclerView.Adapter() {

    val mItems = mutableListOf()
    private var selectAllItems: Boolean = false

    fun updateList(list: List) {
        mItems.addAll(list)
        notifyDataSetChanged()
    }

    fun selectAllItems(selectAll: Boolean){
        selectAllItems = selectAll
        notifyDataSetChanged()
    }

    override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
        val pos = viewHolder.adapterPosition
        viewHolder.checkbox.isSelected = selectAllItems
    }

    class ViewHolder(val view: View): RecyclerView.ViewHolder(view) {
        val checkbox: Checkbox = view.myCheckBox
    }
}