AutoCompleteTextView

（一）

知识点：

1.效果图： 如果列表中没有 可以通过点击button增加到列表中去

 2.activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.app3.MainActivity"
    android:orientation="vertical">

    <AutoCompleteTextView
        android:id="@+id/actv"
        android:completionHint="请输入您的信息"
        android:completionThreshold="2"
        android:background="@color/colorAccent"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button
        android:text="add"
        android:id="@+id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

3.MainActivity.java

package com.example.app3;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.Button;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private AutoCompleteTextView autoCompleteTextView;
    private Button button;
    private List list;
    private String [] books={"XMl","Java","Android","Ajax"};
    private ArrayAdapter arrayAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button)findViewById(R.id.btn);
        autoCompleteTextView = (AutoCompleteTextView)findViewById(R.id.actv);


        list= new ArrayList();
        for (int i=0;i<books.length;i++){
            list.add(books[i]);
        }

        arrayAdapter=new ArrayAdapter(MainActivity.this,android.R.layout.simple_list_item_1,list);

        autoCompleteTextView.setAdapter(arrayAdapter);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String info = autoCompleteTextView.getText().toString();
                list.add(info);

                arrayAdapter=new ArrayAdapter(MainActivity.this,android.R.layout.simple_list_item_1,list);

                autoCompleteTextView.setAdapter(arrayAdapter);

            }
        });





    }
}