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Base Activity

abstract class BaseActivity : Activity(){
    override fun onCreate(savedInstanceState: Bundle?) {
        super
 
.onCreate(savedInstanceState)
        initView()
    }

    abstract fun initView()
    protected fun toast(cxt : Context,text_content : String,toast_time : Int = Toast.LENGTH_SHORT){
        Toast.makeText(cxt,text_content,toast_time).show()
    }
}

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MainActivity

class MainActivity : BaseActivity() {
    private var recycler_view :RecyclerView? = null
    private val data = arrayOf(
           ""
)
    private var list : MutableList<String>? = null
    private var adapter : MyAdapter ? =null
    override fun initView() {
        setContentView(R.layout.activity_main
 
)
        recycler_view = findViewById(R.id.recycle_view)as RecyclerView
        recycler_view!!.layoutManager = LinearLayoutManager(this)
         list= ArrayList<String>()
        for (i in data.indices){
           list!!.add(data[i])
        }
        adapter = MyAdapter(this,list!!)
        recycler_view!!.adapter = adapter
        adapter!!.getListener(MyListener { v, position ->toast(this,"hello$position")  })
    }


}

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Adapter

class MyAdapter(private val ctx : Context,private val list:List<String>) : Adapter<MyViewHolder>() {
   private var listener : MyListener? = null
    private val layout_inflater :LayoutInflater
    init {
        layout_inflater = LayoutInflater.from(ctx)
    }
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
        val view :View = layout_inflater.inflate(R.layout.item,null)
        val holder : MyViewHolder = MyViewHolder(view,listener)
        return holder
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        holder.text_view.text = list.get(position)
    }

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

    class MyViewHolder(itemView: View,private var item : MyListener?)
        : RecyclerView.ViewHolder(itemView),View.OnClickListener{


        val text_view : TextView

        init {
             text_view = itemView.findViewById(R.id.item_text) as TextView
            text_view.setOnClickListener(this)
        }
        override fun onClick(v: View?) {
         item?.itemListener(v,position)
        }
    }
     fun getListener(item: MyListener){
        listener = item
    }
}

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監聽介面

public interface MyListener {
    void itemListener(View v,int position);
}

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事例簡單，沒多少技巧性

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