Question

我将RecyclerView ViewHolder用作复选框，单击该复选框后，我需要取消选择已经选择的另一个复选框，但是这没有发生，更改未反映在视图中。

单击时在onBindViewHolder中初始化Recycler项目单击，更新插槽数据并调用notifyItemChanged，但不更新占位符，我在更新视域时是否会错过任何内容。

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方法中将其选中/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;
    }

要更新旧的复选框以取消选择，请调用notifyDataSetChanged()，因此将对所有可见单元格再次调用onBindHolder()，并进行相应的更新。

在设置notifyDataSetChanged() pos后致电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() ;


    }

RecyclerView取消选择先前选择的复选框

1 个答案: