Kotlin实现recycleview

导入依赖：

  implementation "androidx.recyclerview:recyclerview:1.1.0"
    implementation "androidx.cardview:cardview:1.0.0"

activity：

package com.example.zkotlin

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.recyclerview.widget.LinearLayoutManager
import kotlinx.android.synthetic.main.activity_weather.*

class WeatherActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_weather)
        val examplelist = generateDummyList(50)
        recycler_view.adapter = ExampleAdapter(examplelist)
        recycler_view.layoutManager = LinearLayoutManager(this)
        recycler_view.setHasFixedSize(true)
    }

    private fun generateDummyList(size: Int): List<ExampleItem> {
        val list = ArrayList<ExampleItem>()
        for (i in 0 until size) {
            val drawable = when (i % 3) {
                0 -> R.drawable.ic_android
                1 -> R.drawable.ic_audio
                2 -> R.drawable.ic_sun
                else -> R.mipmap.ic_launcher
            }
            val item = ExampleItem(drawable, "Item $i", "Line 2 ")
            list += item
        }
        return list
    }
}

数据类：

package com.example.zkotlin

data class ExampleItem(val imageResuorce: Int, val text1: String, val text2: String)

适配器：

package com.example.zkotlin

import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import kotlinx.android.synthetic.main.example_item.view.*

class ExampleAdapter(private val exampleList: List<ExampleItem>) :
    RecyclerView.Adapter<ExampleAdapter.ExampleViewHolder>() {


    class ExampleViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val imageView: ImageView = itemView.image_view
        val textView1: TextView = itemView.text_view_1
        val textView2: TextView = itemView.text_view_2
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ExampleViewHolder {
        val itemView =
            LayoutInflater.from(parent.context).inflate(R.layout.example_item, parent, false)
        return ExampleViewHolder(itemView)
    }

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

    override fun onBindViewHolder(holder: ExampleViewHolder, position: Int) {
        val currentItem = exampleList[position]
        holder.imageView.setImageResource(currentItem.imageResuorce)
        holder.textView1.text = currentItem.text1
        holder.textView2.text = currentItem.text2
    }

}

activity布局：

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

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clipToPadding="false"
        android:padding="4dp"
        tools:listitem="@layout/example_item"
        />

</RelativeLayout>

item布局:

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:layout_margin="4dp">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:padding="8dp">

        <ImageView
            android:id="@+id/image_view"
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:layout_marginEnd="8dp"
            android:src="@mipmap/ic_launcher" />

        <TextView
            android:id="@+id/text_view_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_toEndOf="@+id/image_view"
            android:text="line 1"
            android:textColor="@android:color/black"
            android:textSize="18sp"
            android:textStyle="bold" />


        <TextView
            android:id="@+id/text_view_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/text_view_1"
            android:layout_toEndOf="@id/image_view"
            android:text="line 2" />

    </RelativeLayout>
</androidx.cardview.widget.CardView>

效果图：