资源文件都可以在百度云盘中找到： 链接：https://pan.baidu.com/s/1EegFNEv6X2yqi6cJ9iStJQ 提取码：f6zp ___ 为了实现下拉框，这里首先定义主布局文件： ~~~ <?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" tools:context=".MainActivity"> <EditText android:hint="请输入内容" android:id="@+id/editText" android:layout_centerInParent="true" android:layout_width="wrap_content" android:layout_height="wrap_content" android:paddingRight="42dp" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/down_arrow" android:layout_alignRight="@id/editText" android:layout_alignTop="@id/editText" > </ImageView> </RelativeLayout> ~~~ 对应效果：  然后就需要为其添加动态点击事件，以及弹出窗口，对于弹出窗口这里使用popupwindow。也就是在下拉图片点击的时候，就弹出菜单： ~~~ /** * 下拉框 */ class MainActivity : AppCompatActivity() { val editText by lazy {findViewById<EditText>(R.id.editText)} val imageview by lazy {findViewById<ImageView>(R.id.imageview)} var listView: ListView? = null var popupWindow: PopupWindow? = null val datas = listOf("123", "测试", "123", "测试", "123", "测试") override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) listView = ListView(this) listView?.adapter = MyListViewAdapter(this, R.layout.item, datas.toMutableList()) imageview.setOnClickListener(object : View.OnClickListener{ override fun onClick(v: View?) { // 创建PopupWindow if(popupWindow == null){ popupWindow = PopupWindow() popupWindow?.width = editText.width popupWindow?.height = dp2pix(200f) // 指定了布局为动态创建的ListView popupWindow?.contentView = listView popupWindow?.isFocusable = true // 设置焦点，系统就会把各种事件交给popup来处理 } popupWindow?.showAsDropDown(editText, 0, 0) } }) } fun dp2pix(value: Float): Int{ return (resources.displayMetrics.density * value).toInt() } } ~~~ 由于我们在上面代码中指定了popupWindow的布局为一个ListView，这里我们就需要定义一个适配器对象： ~~~ class MyListViewAdapter(context: Context, resource: Int, datas: MutableList<String>): BaseAdapter(){ var mCtx: Context = context var mDatas: MutableList<String> = datas var mResId: Int = resource override fun getCount(): Int { return mDatas.size } override fun getItem(position: Int): Any { return position } override fun getItemId(position: Int): Long { return position.toLong() } override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View { var view: MyViewHolder? = null var tempView: View? = null if(convertView == null){ tempView = View.inflate(mCtx, mResId, null) as View view = MyViewHolder() view.title = tempView.findViewById<TextView>(R.id.textView) view.delete = tempView.findViewById<ImageView>(R.id.delete) } else { tempView = convertView view = tempView.getTag() as MyViewHolder } // 设置标题 val msg = mDatas.get(position) view.title?.text = msg // 设置删除按钮监听 view.delete?.setOnClickListener(object : View.OnClickListener{ override fun onClick(v: View?) { mDatas.remove(msg) // 通知数据发生改变 notifyDataSetChanged() } }) // 缓存实例化的view tempView.setTag(view) return tempView } inner class MyViewHolder{ var delete: ImageView? = null var title: TextView? = null } } ~~~ 当然这里按道理应该使用RecyclerView，因为是巩固和复习一下kotlin这个语言，所以选择了使用ListView。对应的布局item.xml： ~~~ <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:orientation="horizontal" android:layout_height="match_parent"> <TextView android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:padding="10dp" android:text="请输入内容" android:layout_weight="4" android:layout_gravity="center" android:textColor="@color/black" android:textSize="20sp"/> <ImageView android:id="@+id/delete" android:layout_weight="1" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content" app:srcCompat="@drawable/delete" /> </LinearLayout> ~~~ 最终效果就是点击下拉框可展开，然后弹出一个下拉框：  点击X可以进行该项的移除，当然也可以为每项添加一个事件，然后为EditText赋值： ~~~ listView?.setOnItemClickListener(object :AdapterView.OnItemClickListener{ override fun onItemClick( parent: AdapterView<*>?, view: View?, position: Int, id: Long ) { editText.setText(datas[position]) // 关闭窗口 popupWindow?.apply { if(isShowing){ popupWindow?.dismiss() popupWindow = null } } } }) ~~~