AutoCompleteTextView in Android

The AutoCompleteTextView is a type of edit text in android which gives suggestions to the user if the user types something in the AutoCompleteTextView. This type of edit text we can see while we register on some websites. If we type “In” it will suggest India, Indonesia, West Indies ….. etc. Like this, the AutoCompleteTextView works. Let us see the implementation of AutoCompleteTextView in XML and Java . Here XML is used to create the layout and java code is used to implement the main function of AutoCompleteTextView .

Step by Step Implementation

Step 1: Create a New Project

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.

Step 2: Working with the activity_main.xml file

Navigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file. This xml code creates an activity with a TextView and an AutoCompleteTextView under Linearlayout

XML

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

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="This is AutoCompleteTextView"/>

    <AutoCompleteTextView
        android:layout_width="match_parent"
        android:layout_height="100px"
        android:placeholder="Enter your country name"
        android:id="@+id/txtcountries"/>

</LinearLayout>

Step 3: Working with the MainActivity.java file

Go to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.

Java

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;

public class MainActivity extends Activity {

    String[] countries={"India","Australia","West indies","indonesia","Indiana",
                        "South Africa","England","Bangladesh","Srilanka","singapore"};

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,android.R.layout.simple_dropdown_item_1line,countries);
        AutoCompleteTextView textView=(AutoCompleteTextView)findViewById(R.id.txtcountries);
        textView.setThreshold(3);
        textView.setAdapter(adapter);
    }
}

Output:

Explanation:

• Here in the output we can see that when we type “ind” , it has given some suggestions . they are India , Indonesia , Indiana , West Indies .
• In the java code we can customize the country names .
• Basically we create a string array which contains the AutoCompleteTextView list items .
• In the java first we have created a main class and inside the main class we just created a string array named countries consisting country names .
• Then using onCreate() method we have created an activity .
• Then we have created an ArrayAdapter which is used to arrange the countries in dropdown list .
• Then we have invoked the id of AutoCompleteTextView i.e., txtcountries by using findViewById .
• After that we have written textview.setThreshold(4) . Which means 4 items will be displayed in the dropdown list or in suggestions .
• In the example we can see that 4 suggestions were displayed .
• Finally we are setting AutoCompleteTextView object i.e., textview with setAdapter() with ArrayAdapter variable .
• textview.setAdapter(adapter) . Thus the AutoCompleteTextView can be linked with that dropdown list .