关注 安卓007 ,免费获取全套安卓开发学习资料
什么是ListViewListView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- 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)
}
}
- ListViewAdapter对应布局文件: item_layout.xml
基础样例完整源代码
https://gitee.com/cxyzy1/ListViewDemo
安卓开发入门教程系列汇总 开发语言学习Kotlin语言基础
UI控件学习系列UI控件_TextView UI控件_EditText UI控件_Button UI控件_ImageView UI控件_RadioButton UI控件_CheckBox UI控件_ProgressBar
关注头条号,第一时间获取最新文章: