EditText既可以输入编辑也可以下拉选择 EditText +ListPopupWindow

1、效果展示

2、布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="com.example.lum.mylistpopupwindow.MainActivity">

    <EditText
        android:id="@+id/edit_id"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入账户："
        android:textSize="30dp"
        android:layout_marginTop="60dp"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp" />

</LinearLayout>

3、功能实现

package com.example.lum.mylistpopupwindow;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListPopupWindow;

public class MainActivity extends AppCompatActivity implements View.OnFocusChangeListener {

    private EditText mEditText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mEditText = (EditText) findViewById(R.id.edit_id);
        mEditText.setOnFocusChangeListener(this);  //对edit 进行焦点监听

    }

    @Override
    public void onFocusChange(View v, boolean hasFocus) {
        if (hasFocus) {
            showListPopulWindow(); //调用显示PopuWindow 函数
        }
    }

    private void showListPopulWindow() {
        final String[] list = {"1", "2", "3","4","5","6","7","8","9","0"};//要填充的数据
        final ListPopupWindow listPopupWindow;
        listPopupWindow = new ListPopupWindow(this);
        listPopupWindow.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, list));//用android内置布局，或设计自己的样式
        listPopupWindow.setAnchorView(mEditText);//以哪个控件为基准，在该处以mEditText为基准
        listPopupWindow.setModal(true);

        listPopupWindow.setOnItemClickListener(new AdapterView.OnItemClickListener() {//设置项点击监听
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                mEditText.setText(list[i]);//把选择的选项内容展示在EditText上
                listPopupWindow.dismiss();//如果已经选择了，隐藏起来
            }
        });
        listPopupWindow.show();//把ListPopWindow展示出来
    }

}

文章参考：
1、【Android】EditText下拉菜单ListPopupWindow
https://blog.csdn.net/crab0314/article/details/79608705

2、EditText+ListPopupWindow实现可编辑的下拉列表
https://blog.csdn.net/u014293306/article/details/52402537

3、Android开发笔记（一百二十一）列表弹窗PopupMenu和ListPopupWindow
https://www.2cto.com/kf/201608/543275.html

4、Android自定义PopupWindow显示在控件上方或者下方
https://www.cnblogs.com/woaixingxing/p/5563171.html

5、PopupWindow学习之弹出方向（一）
https://blog.csdn.net/final1992/article/details/50487435

6、android PopupWindow在控件的各个方向上的显示
https://blog.csdn.net/kujing823/article/details/53100876