package com.loaderman.dropbox;

import android.app.Activity;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.PopupWindow;
import android.widget.TextView;

import java.util.ArrayList;

public class MainActivity extends Activity {

    private ImageView ivDrop;
    private ListView lvList;
    private EditText etInput;
    private ArrayList<String> mList;
    private PopupWindow popup;
    private MyAdapter mAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ivDrop = (ImageView) findViewById(R.id.iv_drop);
        etInput = (EditText) findViewById(R.id.et_input);
        ivDrop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showPopup();
            }
        });
        lvList = new ListView(this);
        lvList.setBackgroundResource(R.drawable.listview_background);
        initData();
        lvList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                etInput.setText(mList.get(position));
                popup.dismiss();
            }
        });
    }
    private void initData() {
        mList = new ArrayList<>();
        for (int i = 0; i < 200; i++) {
            mList.add("用户名" + i);
        }
        mAdapter = new MyAdapter();
        lvList.setAdapter(mAdapter);
    }
    private void showPopup() {
        popup = new PopupWindow(lvList, etInput.getWidth(), 200, true);
        popup.setBackgroundDrawable(new ColorDrawable());
        popup.showAsDropDown(etInput, 0, 0);
    }
    class MyAdapter extends BaseAdapter {
        @Override
        public int getCount() {
            return mList.size();
        }
        @Override
        public Object getItem(int position) {
            return null;
        }
        @Override
        public long getItemId(int position) {
            return position;
        }
        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            ViewHolder holder;
            if (convertView == null) {
                convertView = View.inflate(MainActivity.this, R.layout.list_item, null);
                holder = new ViewHolder();
                holder.tvName = (TextView) convertView.findViewById(R.id.tv_name);
                holder.ivDelete = (ImageView) convertView.findViewById(R.id.iv_delete);
                convertView.setTag(holder);
            } else {
                holder = (ViewHolder) convertView.getTag();
            }
            holder.tvName.setText(mList.get(position));
            holder.ivDelete.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    mList.remove(mList.get(position));
                    mAdapter.notifyDataSetChanged();
                }
            });
            return convertView;
        }
    }
    static class ViewHolder {
        public TextView tvName;
        public ImageView ivDelete;
    }
}

 activity_main.xml

<?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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"
    tools:context="com.loaderman.dropbox.MainActivity">


    <RelativeLayout
        android:layout_width="400dp"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true">

        <EditText
            android:id="@+id/et_input"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>

        <ImageView
            android:id="@+id/iv_drop"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_alignParentRight="true"
            android:layout_marginRight="5dp"
            android:layout_centerVertical="true"
            android:src="@drawable/down_arrow"/>

    </RelativeLayout>

</RelativeLayout>

 list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center_vertical"
    android:orientation="horizontal"
    android:padding="10dp">
    <!--list_item-->
    <ImageView
        android:id="@+id/imageView"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:src="@drawable/user"/>

    <TextView
        android:id="@+id/tv_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:gravity="center"
        android:text="文字"
        android:textSize="18sp"/>

    <ImageView
        android:id="@+id/iv_delete"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:src="@drawable/delete"/>
</LinearLayout>

 效果图:

自定义布局实现下拉列表条目选择功能的实现_用户名