RecyclerView取消选择之前选择的复选框

Question

我将 RecyclerView ViewHolder 作为复选框，单击该复选框后，我需要取消选择已选择的其他复选框，但它没有发生，更改不会反映在视图中。

单击时在 onBindViewHolder 中初始化回收器项目单击，更新槽数据并调用notifiedItemChanged，但占位符未更新，我是否错过了更新视图持有者的任何内容。

override fun onBindViewHolder(
    holder: BookingSlotListItemViewHolder,
    position: Int,
    payloads: MutableList<Any?>
 )

---

class BookingSlotListAdapter(
    private val hourSlotHolder: RecyclerView,
    private val bookingBtn: TextView
    ) : RecyclerView.Adapter<BookingSlotListItemViewHolder>() {
    private val bookingSlots = ArrayList<BookingSlotAvailability>()
    private var lastSelected: Int? = null
    private val bookingHourItemAdapter = BookingHourItemAdapter(bookingBtn)
    private val NOT_SELECTED_FOR_BOOKING = 0
    private val AVAILABLE_FOR_BOOKING = false

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BookingSlotListItemViewHolder {
        val layoutInflater: LayoutInflater = LayoutInflater.from(parent.context)
        val view = layoutInflater.inflate(R.layout.booking_time_slot, parent, false)
        return BookingSlotListItemViewHolder(view)
    }

    override fun getItemCount(): Int {
        if (bookingSlots.isNullOrEmpty()) {
        return 0
        }
        return bookingSlots.size
    }

    fun setBookingSlots(bookingSlots: TreeMap<String, Boolean>) {
        bookingSlots.map {
            this.bookingSlots.add(BookingSlotAvailability(it.key, it.value, NOT_SELECTED_FOR_BOOKING))
        }
    }

    override fun onBindViewHolder(holder: BookingSlotListItemViewHolder, position: Int) {
        holder.timeSlot.text = bookingSlots[position].time
        if (!bookingSlots[position].isAvailable) {
        holder.timeSlot.isEnabled = false
        }
        if (bookingSlots[position].selectionStatus == 0 && holder.timeSlot.isChecked) {
        holder.timeSlot.toggle()
        } else if (bookingSlots[position].selectionStatus == 1 && !holder.timeSlot.isChecked) {
        holder.timeSlot.toggle()
        }

        holder.timeSlot.setOnClickListener { view: View? ->
        Log.v("CLICKED", "BookingSlotListAdapter: $lastSelected : $position")
        val selectedSlot = view as CheckBox

        if (lastSelected != null) {
            bookingSlots[lastSelected!!].isAvailable = AVAILABLE_FOR_BOOKING
            bookingSlots[lastSelected!!].selectionStatus = NOT_SELECTED_FOR_BOOKING
            notifyItemChanged(
            lastSelected,
            bookingSlots[lastSelected!!]
            )
        }
        bookingSlots[position].isAvailable = NOT_AVAILABLE
        bookingSlots[position].selectionStatus = SELECTED_FOR_BOOKING
        notifyItemChanged(
            position,
            bookingSlots[position]
        )
        lastSelected = position
        }
    }

    override fun onBindViewHolder(
        holder: BookingSlotListItemViewHolder,
        position: Int,
        payloads: MutableList<Any?>
    ) {
        super.onBindViewHolder(holder, position, payloads)
        Log.v("OVERLOADEDVH", "$payloads $position")
    }
}

Answer 1

您需要在 onBindViewholder 方法中对其进行选中/取消选中，因为当我们滚动 recyclerView 时，它会重用视图并再次创建视图，因此它不知道 checkBox 的最后状态：

    // Add these lines below at then end of onBindViewHolder
    val selectedSlot = holder.timeSlot as CheckBox

    if(lastSelected == position){
        selectedSlot.isChecked = true;
    }else{
        selectedSlot.isChecked = false;
    } 

要更新旧复选框以取消选择，请调用notifyDataSetChanged()，因此onBindHolder()将为所有可见单元格再次调用，并将相应更新。

notifyDataSetChanged()设置 pos 后调用lastSelected：

    holder.timeSlot.setOnClickListener { view: View? ->
    Log.v("CLICKED", "BookingSlotListAdapter: $lastSelected : $position")
    val selectedSlot = view as CheckBox

    if (lastSelected != null) {
        bookingSlots[lastSelected!!].isAvailable = AVAILABLE_FOR_BOOKING
        bookingSlots[lastSelected!!].selectionStatus = NOT_SELECTED_FOR_BOOKING

        //COMMENT  notifyDataSetChanged WILL HANDLE ALL
        //notifyItemChanged(
        //lastSelected,
        //bookingSlots[lastSelected!!]
        //)
    }
    bookingSlots[position].isAvailable = NOT_AVAILABLE
    bookingSlots[position].selectionStatus = SELECTED_FOR_BOOKING

    //COMMENT  notifyDataSetChanged WILL HANDLE ALL
    //notifyItemChanged(
    //    position,
    //    bookingSlots[position]
    //)
    lastSelected = position

     //------CALL notifyDataSetChanged() for all visible cells------
     notifyDataSetChanged() ;


    }