TextView的升级版———AutoCompleteTextView

AutoCompleteTextView顾名知义，可以自动提示的TextView，还可以提示错误信息。

这里介绍基本的使用，能够满足绝大部分需求

效果图

XML布局

<?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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <AutoCompleteTextView
        android:id="@+id/actv_username"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="用户名" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="error"
        android:text="提示错误" />
</LinearLayout>

测试类

package com.example.kongqw.autocompletetextviewdemo;

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

public class MainActivity extends AppCompatActivity {

    private AutoCompleteTextView mAutoCompleteTextView;

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

        mAutoCompleteTextView = (AutoCompleteTextView) findViewById(R.id.actv_username);
        String[] emailAddressCollection = {"kongqw@foxmail.com", "qq4878802", "123@qq.com", "123456789", "123888888"};
        ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_dropdown_item_1line, emailAddressCollection);
        mAutoCompleteTextView.setAdapter(adapter);
    }

    // 提示错误
    public void error(View view){
        mAutoCompleteTextView.setError("这里是错误提示");
    }
}

自动提示

核心方法就是AutoCompleteTextView的setAdapter()

这里模拟了几个已经记住的字符串，实际应用当中，这些数据可以读数据或者怎样，根据实际情况

mAutoCompleteTextView = (AutoCompleteTextView) findViewById(R.id.actv_username);
String[] emailAddressCollection = {"kongqw@foxmail.com", "qq4878802", "123@qq.com", "123456789", "123888888"};
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_dropdown_item_1line, emailAddressCollection);
mAutoCompleteTextView.setAdapter(adapter);

显示错误信息

mAutoCompleteTextView.setError("这里是错误提示");

修改下划线颜色

修改res->values->styles.xml下”AppTheme”里的colorAccent属性

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    ……
    <item name="colorAccent">#00DD00</item>
</style>