什么是ListView

ListView是用于显示列表的UI控件.不过当前主流的已经是RecyclerView了,更强大,更好用.

基础样例

效果图

方案简要介绍

在activity对应的布局文件中增加ListView

新增一个Adapter用于展示列表中每一行内容(含对应布局文件)
详见下面完整代码中的ListViewAdapter及其布局文件.

在activity中实例化Adapter,设置数据,并将adapter设置给ListView

private fun initListView() {
       var dataList = getData()    val adapter = ListViewAdapter(this)    adapter.setData(dataList)    listView.adapter = adapter    //隐藏自带的分隔符，在ListViewAdapter对应的布局里自定义分隔符，这样可以更灵活。    listView.divider = null    //添加点击事件    listView.setOnItemClickListener {
    adapterView, _, position, _ ->        val text = adapterView.getItemAtPosition(position).toString()        toast(text)    }}private fun getData(): List
   
     {
       val dataList = ArrayList
    
     ()    for (index in 0 until 100) {
           val text = " 数据$index "        dataList.add(text)    }    return dataList}

完整代码

activity代码:MainActivity

class MainActivity : AppCompatActivity() {
       override fun onCreate(savedInstanceState: Bundle?) {
           super.onCreate(savedInstanceState)        setContentView(R.layout.activity_main)        initListView()    }    private fun initListView() {
           var dataList = getData()        val adapter = ListViewAdapter(this)        adapter.setData(dataList)        listView.adapter = adapter        //隐藏自带的分隔符，在ListViewAdapter对应的布局里自定义分隔符，这样可以更灵活。        listView.divider = null        //添加点击事件        listView.setOnItemClickListener {
    adapterView, _, position, _ ->            val text = adapterView.getItemAtPosition(position).toString()            toast(text)        }    }    private fun getData(): List
   
     {
           val dataList = ArrayList
    
     ()        for (index in 0 until 100) {
               val text = " 数据$index "            dataList.add(text)        }        return dataList    }    /**     * 显示toast短暂提示     */    private fun toast(text: String) = Toast.makeText(this, text, Toast.LENGTH_SHORT).show()}

MainActivity对应布局文件: activity_main.xml

ListView对应Adapter: ListViewAdapter

class ListViewAdapter(var context: Context) : BaseAdapter() {
       private var mDataList = mutableListOf
   
    ()    /**     * 设置数据     */    fun setData(dataList: List
    
     ) {
           mDataList.clear()        mDataList.addAll(dataList)        //数据变更后，需要调用notifyDataSetChanged通知数据变化。        notifyDataSetChanged()    }    override fun getView(position: Int, convertView: View?, viewGroup: ViewGroup?): View {
           var viewHolder: ViewHolder        var view: View        //下面对convertView进行判断，是为了复用已存在的视图，提升效率。        if (convertView == null) {
               view = View.inflate(context, R.layout.item_layout, null);            viewHolder = ViewHolder(view)            view.tag = viewHolder        } else {
               view = convertView            viewHolder = view.tag as ViewHolder        }        //获取当前位置数据        val item = getItem(position)        //显示用户名        if (item is String) {
               viewHolder.nameTv.text = item        }        return view    }    override fun getItem(position: Int): Any {
           return mDataList[position]    }    override fun getItemId(position: Int): Long {
           return 0    }    override fun getCount(): Int {
           return mDataList.size    }    class ViewHolder(view: View) {
           var nameTv: TextView = view.findViewById(R.id.nameTv)    }}