选中时防止按钮变为透明

我有一个 recyclerview 有一排按钮。我的目标是使当前选定的按钮的文本为青色,而其他按钮的文本为灰色。

为此,我在 TabAdapter 班级:

class TabAdapter(private val items: ArrayList<Pair<String, ArrayList<String>>>, private val context: Context) : RecyclerView.Adapter<TabViewHolder>() {
private var selectedPosition: Int = RecyclerView.NO_POSITION

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): TabViewHolder {
    return TabViewHolder(LayoutInflater.from(context).inflate(R.layout.tabrecycler_item_column, parent, false))
}

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

override fun onBindViewHolder(holder: TabViewHolder, position: Int) {

    context as AnimeFaceKeyboard

    holder.itemView.isSelected = selectedPosition == position

    if (holder.itemView.isSelected) {
        holder.button.setTextColor(ContextCompat.getColor(context, R.color.material_deep_teal_200))
    } else {
        holder.button.setTextColor(ContextCompat.getColor(context, R.color.material_grey_600))
    }


    //This code sets the widths of the buttons to, at minimum,
    //occupy the entire width of the screen combined 
    val displayMetrics = Resources.getSystem().displayMetrics

    if (itemCount * (120 * displayMetrics.density) < displayMetrics.widthPixels) {
        holder.button.width = displayMetrics.widthPixels / itemCount
    }


    holder.button.text = items[position].first
    holder.button.setOnClickListener {

        //TODO - Figure out how this code works
        notifyItemChanged(selectedPosition)
        selectedPosition = holder.layoutPosition
        notifyItemChanged(selectedPosition)

        //This code updates a different recyclerview. 
        context.isFavoritesTabSelected = position == items.lastIndex
        context.updateCurrentImageLayout(items[position].second)
    }
}

}
class TabViewHolder(view: View) : RecyclerView.ViewHolder(view) {
val button: Button = view.tabButton

}

相关线路在 onBindViewHolder 方法。特别是这条线

holder.itemView.isSelected = selectedPosition == position

这段代码在 onClick 按钮的方法

        notifyItemChanged(selectedPosition)
        selectedPosition = holder.layoutPosition
        notifyItemChanged(selectedPosition)

下面是 回收视图 :

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/tabButton"
        android:layout_width="match_parent"
        android:minWidth="120dp"
        android:layout_height="match_parent"
        android:text="Unset-Button-Text"
        android:background="@color/darkshade"
        style="@style/Widget.AppCompat.Button.Borderless"/>


</android.support.constraint.ConstraintLayout>

我的行为 recyclerView 是部分功能。当前选定按钮的文本,实际上是青色的。

但是,有两个问题

1]点击按钮时,按钮部分变为透明。点击涟漪动画一定有问题

和

2]涟漪动画只应为选定的当前按钮播放,但也会为先前选定的按钮播放。

以下是我手机上的gif演示: