Android - Kotlin으로 RecyclerView 구현하기

build.gradle(Moudle) viewBinding true 설정 

 

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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:id="@+id/parent"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

 

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item_recycler.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:gravity="center"
    android:orientation="horizontal">

    <TextView
        android:id="@+id/textNo"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="01" />

    <TextView
        android:id="@+id/textTitle"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="5"
        android:text="Title" />

    <TextView
        android:id="@+id/textDate"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="3"
        android:text="2021-01-01" />
</LinearLayout>

 

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아래와 같이 데이터 클래스를 만들어 줍니다. 

 

Memo.kt

data class Memo(var no: Int, var title: String, var timestamp: Long)

 

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AdapterClass도 만들어 줍니다

 

CustomAdapter.kt

import android.view.LayoutInflater
import android.view.ViewGroup
import android.widget.Toast
import androidx.recyclerview.widget.RecyclerView
import org.techtown.location.kotlinproject.databinding.ItemRecyclerBinding
import java.text.SimpleDateFormat

class CustomAdapter: RecyclerView.Adapter<Holder>() {
    var listData = mutableListOf<Memo>()

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): Holder {
        val binding = ItemRecyclerBinding.inflate(LayoutInflater.from(parent.context),
                                                    parent, false);

        return Holder(binding)
    }

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

    override fun onBindViewHolder(holder: Holder, position: Int) {
        val memo = listData.get(position)
        holder.setMemo(memo)
    }
}

class Holder(val binding: ItemRecyclerBinding): RecyclerView.ViewHolder(binding.root){

    init{
        binding.root.setOnClickListener{
            Toast.makeText(binding.root.context, "클릭된 아이템 = ${binding.textTitle.text}",
                           Toast.LENGTH_LONG).show()
        }
    }

    fun setMemo(memo: Memo){
        binding.textNo.text = "${memo.no}"
        binding.textTitle.text = memo.title
        var sdf = SimpleDateFormat("yyyy/MM/dd")
        binding.textDate.text = sdf.format(memo.timestamp)
    }
}

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MainActivity.kt

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.StaggeredGridLayoutManager
import org.techtown.location.kotlinproject.databinding.ActivityMainBinding
import kotlin.concurrent.thread

class MainActivity : AppCompatActivity() {
    val binding by lazy { ActivityMainBinding.inflate(layoutInflater)}

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)

        var adapter = CustomAdapter()
        adapter.listData = loadData()
        binding.recyclerView.adapter = adapter

        /* recycyclerView Option */
          binding.recyclerView.layoutManager = LinearLayoutManager(this)
        // binding.recyclerView.layoutManager = LinearLayoutManager(this,
                                             //LinearLayoutManager.HORIZONTAL,false)
        // GridLayoutManager(this, 3)
        // StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL)

    }


    fun loadData(): MutableList<Memo>{
        val data : MutableList<Memo> = mutableListOf()

        for(no in 1..100){
            val title = "예제 ${no} 입니다 "
            val date = System.currentTimeMillis()
            var memo = Memo(no, title, date)
            data.add(memo)
        }

        return data
    }
}

 

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[결과]