android - 如何使用 Kotlin 在 Android Studio 中的 RecyclerView 上添加 Onclick 监听器？

Question

所以我想在 Android 中为我的 RecyclerView 设置一个 onclicklistener，但我不确定该怎么做。

我的 Workoutlist 有一个 CustomAdapterClass，如下所示:

class CustomAdapter(val workoutList: ArrayList<workout>) : RecyclerView.Adapter<CustomAdapter.ViewHolder>() {

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomAdapter.ViewHolder {
    val v = LayoutInflater.from(parent.context).inflate(R.layout.list_layout, parent, false)
    return ViewHolder(v)
}

override fun onBindViewHolder(holder: CustomAdapter.ViewHolder, position: Int) {
    holder.bindItems(workoutList[position])
}

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

class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

    fun bindItems(workout: workout) {
        val cardDate = itemView.findViewById<TextView>(R.id.cardDate)
        val cardDescription  = itemView.findViewById<TextView>(R.id.cardDescription)
        cardDate.text = workout.date
        cardDescription.text = workout.description
    }
}
}

然后我像这样推进我的锻炼(在我的Main Activity中):

    val recyclerView = findViewById<RecyclerView>(R.id.RecyclerView)

    recyclerView.layoutManager = GridLayoutManager(this, 3)


    val workouts = ArrayList<workout>()

    workouts.add(workout("12.09.2018", "Kniebeugen und Bizeps + Rücken"))
    workouts.add(workout("12.09.2018", "Kniebeugen und Bizeps + Rücken"))
    workouts.add(workout("12.09.2018", "Kniebeugen und Bizeps + Rücken"))
    workouts.add(workout("12.09.2018", "Kniebeugen und Bizeps + Rücken"))
    workouts.add(workout("12.09.2018", "Kniebeugen und Bizeps + Rücken"))
    workouts.add(workout("12.09.2018", "Kniebeugen und Bizeps + Rücken"))
    workouts.add(workout("12.09.2018", "Kniebeugen und Bizeps + Rücken"))
    workouts.add(workout("12.09.2018", "Kniebeugen und Bizeps + Rücken"))

    val adapter = CustomAdapter(workouts)

    recyclerView.adapter = adapter

我想让我的锻炼可以点击，这样我就可以使用锻炼中的名称和描述来打开一个新的 Activity ，并将它们作为 Intent 。

感谢任何帮助!

我不明白他把那个扩展名放在“副本”中的什么地方

Answer 1

1. 让我们为这个用例定义一个接口(interface):

   interface WorkoutClickLisetner{
      fun onWorkoutClicked(workout: workout)
   }
   

2. 添加WorkoutClickListener作为 CustomAdapter 的成员

   var listener : WorkoutClickListener? = null
   

   为 itemView 注册点击监听器在你的里面 bindItems方法

   itemView.listener = object : View.OnClickListener {
   
     override fun onClick(v: View){
       listener?.onWorkoutClicked(workout)
     }
   }
   

3. 不要忘记初始化你的 WorkoutClickListener当用户单击单元格时，您将在其中委托(delegate)操作:

   val adapter = CustomAdapter(workouts)
   
   adapter.listener = object : WorkoutClickListener { 
       override fun onWorkoutClicked(workout: workout){  
      /*your delegation goes here*/`
    }
   }
   
   recyclerView.adapter = adapter