如何取消选择 Recycler 视图的一行

Question

I'm trying to deselect the selected rows of a Recycler View.

I've been using manager.findViewByPosition(position); to get the views in recycler view, but the problem is this method returns only the views that are appearing on the screen. I want to get recycler views that are offscreen also.

Is there any other way to solve this this problem?

Answer 1

This is a simple way to achieve what you are trying to do, there are several ways to do this but I hope this quick example helps you get started.

If you struggle to understand the logic, I would ask you to post your recycler code so I can help you better.

class MyAwesomeRecycler : RecyclerView.Adapter<MyAwesomeRecycler.ViewHolder>() {

    val myAwesomeStrings = arrayOf("...")
    val selectedPositions = arrayListOf<Int>()

    class ViewHolder(var view: View): RecyclerView.ViewHolder(view){
        //TODO
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        TODO("Not yet implemented")
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.view.setOnLongClickListener {
            if(selectedPositions.contains(position)) {
                selectedPositions.remove(position)
            } else {
                selectedPositions.add(position)
            }
            true
        }

        if(selectedPositions.contains(position)){
            holder.someView.text = "I'm selected"
        } else {
            holder.someView.text = "I'm not selected"
        }
    }

    override fun getItemCount(): Int {
        return myAwesomeStrings.size
    }
}

selectedPositions array will contain the index of the rows that the user selected.

Let me know if you don't understand the logic behind this.