[ANDROID] KOTLIN – RECYCLER VIEW

RecyclerView는 안드로이드의 ListView의 장/단점을 보완하고자 사용하는 위젯입니다.

SupportLibrary에 포함되며 v7 이상에서 사용 가능합니다.

RecyclerView는 LayoutManager를 통해서 View를 그리는 방법을 정의합니다.

 

 

res/layout/activity_main.xml

<xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
 
    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/cLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        >
 
        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/rvList"
            android:layout_width="match_parent"
            android:layout_height="match_parent">
 
        </androidx.recyclerview.widget.RecyclerView>
 
    </androidx.constraintlayout.widget.ConstraintLayout>
 
</androidx.constraintlayout.widget.ConstraintLayout>

 

res/layout/item_list.xml

<xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
 
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_vertical"
        android:orientation="vertical"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">
 
        <TextView
            android:id="@+id/tvItem"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
 
    </LinearLayout>
 
</androidx.constraintlayout.widget.ConstraintLayout>

 

kr.kotlin.test.main.activity.MainActivity

package kr.kotlin.test.main.activity
 
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import kr.kotlin.test.vo
import kr.kotlin.test.R
import kr.kotlin.test.main.adapter.MainAdapter
import kotlinx.android.synthetic.main.activity_main.*
 
class MainActivity : AppCompatActivity() {
 
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
 
 
        //레이아웃매니저 설정
        rvList.layoutManager = LinearLayoutManager(this, RecyclerView.VERTICAL, false)
        rvList.setHasFixedSize(true)
 
        //어답터 설정
        rvList.adapter = MainAdapter(initData())
 
 
    }
 
    fun initData(): MutableList<BoardVO> {
 
        var itemList: MutableList<BoardVO> = arrayListOf()
 
        itemList.add(BoardVO("KOTLIN"))
        itemList.add(BoardVO("PROGRAMMING"))
        itemList.add(BoardVO("TEST"))
        itemList.add(BoardVO("FINISH"))
 
        return itemList
    }
}

kr.kotlin.test.main.adapter.MainAdapter

package kr.kotlin.test.main.adapter
 
import android.view.LayoutInflater
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import kr.kotlin.test.R
import kotlinx.android.synthetic.main.item_list.view.*
import kr.kotlin.test.main.vo
 
 
class mainAdapter(initData: MutableList<BoardVO>) : RecyclerView.Adapter<MainAdapter.CustomHolder>() {
 
    private var items: MutableList<BoardVO> = initData
 
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) = MainAdapter.CustomHolder(parent)
 
    override fun onBindViewHolder(holder: CustomHolder, position: Int) {
 
        items[position].let { item ->
 
            holder!!.tvItem.text = item.title
 
        }
    }
 
    override fun getItemCount() = items.size
 
    fun addItems(items: List<Service>) {
        this.items.addAll(items.toMutableList())
    }
 
    fun clearItems() {
        this.items.clear()
        notifyDataSetChanged()
    }
 
    class CustomHolder constructor(parent: ViewGroup) : RecyclerView.ViewHolder(
            LayoutInflater.from(parent.context).inflate(R.layout.item_list, parent, false)) {
        val context = itemView.context
        val tvItem = itemView.tvItem
 
    }
 
 
}
 

kr.kotlin.test.main.vo.BoardVO

package kr.kotlin.test.main.vo
 
class BoardVO(title:String) {
    var title: String = title
}