kotlin实现简单的GridView

使用kotlin实现简单的GridView

xml代码

activity_main代码

<RelativeLayout 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"
    tools:context=".MainActivity">

    <GridView
        android:layout_width="1600px"
        android:layout_height="800px"
        android:id="@+id/gridView"
        android:layout_centerInParent="true"
        android:numColumns="2"/>

RelativeLayout>

GridView子项布局grid_view代码

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/Realtive">

    <ImageView
        android:id="@+id/image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"/>

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#fff"
        android:textSize="25sp"
        android:layout_centerInParent="true"/>

RelativeLayout>

kotlin代码

实体类代码

package com.example.yyr2_7

/**
 *@创建者:      yuyiran
 *@创建日期:    2020-5-26 9:07
 *@描述:      数据类
 */
class IotResource(val imageId: Int,val text:String,val colorId:Int) {
}

适配器代码

package com.example.yyr2_7

import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.BaseAdapter
import android.widget.ImageView
import android.widget.RelativeLayout
import android.widget.TextView

/**
 *@创建者:      yuyiran
 *@创建日期:    2020-5-26 8:57
 *@描述:      适配器
 */
class MyAdapter (var context: Context,var datas:ArrayList<IotResource>) : BaseAdapter(){

    inner class MyHolder(){
        lateinit var imageId : ImageView
        lateinit var text : TextView
        lateinit var mRelative : RelativeLayout
    }

    override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View {
//        var view:View ?= null
//        var myHolder:MyHolder ?= null

        var view:View ?= null
        var myHolder:MyHolder ?= null

        if(convertView == null){
            myHolder = MyHolder()
            view = LayoutInflater.from(context).inflate(R.layout.grid_view,null)
            myHolder.imageId = view.findViewById(R.id.image)
            myHolder.text = view.findViewById(R.id.textView)
            myHolder.mRelative = view.findViewById(R.id.Realtive)
            view.tag = myHolder
        }else{
            view = convertView
            myHolder = view.tag as MyHolder
        }

        myHolder.text.setText(datas.get(position).text)
        myHolder.imageId.setImageResource(datas.get(position).imageId)
        myHolder.mRelative.setBackgroundColor(datas.get(position).colorId)

        return view!!
    }

    override fun getItem(position: Int): Any {
        //获取指定位置(position)上的item对象，通常不需要修改
        return datas.get(position)
    }

    override fun getItemId(position: Int): Long {
        // 获取指定位置(position)上的item的id，通常不需要修改
        return position.toLong()
    }

    override fun getCount(): Int {
        //返回一个整数,就是要在listview中现实的数据的条数
        return datas.size
    }

}

MainActivity代码

package com.example.yyr2_7

import android.graphics.Color
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_main.*
import kotlin.random.Random

class MainActivity : AppCompatActivity() {

    var list:ArrayList<IotResource> ?= ArrayList()
    var texts = arrayOf<String>("环境气象","智能商场","预警信息","智能农场")
    var pics = arrayOf<Int>(R.drawable.icon_weather,R.drawable.icon_shopping,R.drawable.icon_security,R.drawable.icon_agriculture)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        initIotResource()
        gridView.adapter = MyAdapter(this,list!!)
    }

    private fun initIotResource(){
        for(i in 1..100){
            val randomNum = (0..3).random()
//            val text = texts[(0..3).random()]
//            val pic = pics[i]
//            val colors = RandomColor()
            list?.add(IotResource(pics[randomNum],texts[randomNum],RandomColor()))
//            list?.add(IotResource(pics[i],"texts[i]",RandomColor()))
        }
    }

    private fun RandomColor():Int{
        var r = Random.nextInt(256)
        var g = Random.nextInt(256)
        var b = Random.nextInt(256)
        return Color.rgb(r,g,b)
    }
}

效果图