在 RecyclerView 中单击项目时如何更改 Alpha 的值？

Question

我无法弄清楚如何在单击 RecyclerView 的项目时更改 alpha 的值。我想将 alpha 的值从 1 更改为 0.5 。

下面是相同的适配器 Class。

    package GiftClass
    
    import LeaderboardClass.LeaderboardAdapter
    import android.view.LayoutInflater
    import android.view.View
    import android.view.ViewGroup
    import android.widget.ImageView
    import android.widget.TextView
    import androidx.recyclerview.widget.RecyclerView
    import com.gearsrun.www.R
    import kotlinx.android.synthetic.main.item_gift.view.*
    
    class GiftAdapter(private val giftList: List<Gift>) : RecyclerView.Adapter<GiftAdapter.GiftViewHolder>() {
       private lateinit var mlistener : onItemClickListener
       interface onItemClickListener{
           fun onItemClick(position: Int)
       }
        fun setOnItemClickListener(listener: onItemClickListener){
            mlistener = listener
        }
    
        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): GiftViewHolder {
           val itemView = LayoutInflater.from(parent.context).inflate(R.layout.item_gift,parent,false)
            return GiftViewHolder(itemView,mlistener)
        }
    
        override fun onBindViewHolder(holder: GiftViewHolder, position: Int) {
          val currentItem = giftList[position]
            holder.item_img.setImageResource(currentItem.imageResource)
            holder.item_price.text = currentItem.price
            holder.item_soldNum.text = currentItem.sold_num
            holder.item_medal.text = currentItem.medal_num
        }
    
        override fun getItemCount() = giftList.size
    
        class GiftViewHolder(itemView: View,listener:onItemClickListener) : RecyclerView.ViewHolder(itemView){
            val item_img:ImageView = itemView.item_img
            val item_price : TextView = itemView.price
            val item_soldNum : TextView = itemView.sold_num
            val item_medal : TextView = itemView.medal_num
    
            init {
                itemView.setOnClickListener {
                    listener.onItemClick(absoluteAdapterPosition)
                     itemView.alpha = 0.5f
                }
            }
    
        }
    }

感谢添加参考/建议

Answer 1

在 onClickListener 中，您可以获得属性 itemView.alpha 并根据需要调整 alpha 值

在 RecyclerView 中单击项目时如何更改 Alpha 的值？

How to change the value of Alpha when item is clicked inside RecyclerView?

android

kotlin

android-recyclerview

alpha