Android AutoCompleteTextView and MultiAutoCompleteTextView Tutorial with Examples

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    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=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="40dp"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="30dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:text="Full name"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/editText"
        android:layout_width="0dp"
        android:layout_height="46dp"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="31dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:ems="10"
        android:inputType="textPersonName"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="0dp"
        android:layout_height="37dp"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="32dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:text="Country"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/editText" />

    <AutoCompleteTextView
        android:id="@+id/autoCompleteTextView"
        android:layout_width="0dp"
        android:layout_height="53dp"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="25dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView2" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="0dp"
        android:layout_height="32dp"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="26dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:text="Programming Languages"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/autoCompleteTextView" />

    <MultiAutoCompleteTextView
        android:id="@+id/multiAutoCompleteTextView"
        android:layout_width="0dp"
        android:layout_height="51dp"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="22dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView3" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="34dp"
        android:text="Submit"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/multiAutoCompleteTextView" />
</androidx.constraintlayout.widget.ConstraintLayout>

package org.o7planning.androidautocompletetextview;

import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.MultiAutoCompleteTextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private EditText textFullname;
    private  AutoCompleteTextView textCountry;
    private  MultiAutoCompleteTextView textProgrammingLanguage;

    private Button buttonSubmit;

    private String[] countries = {"Vietnam","England","Canada", "France","Australia"};

    private String[] languages={"Java ","CSharp","Visual Basic","Swift","C/C++"};

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

        textFullname = (EditText) findViewById(R.id.editText);
        textCountry =(AutoCompleteTextView)findViewById(R.id.autoCompleteTextView);
        textProgrammingLanguage =(MultiAutoCompleteTextView)findViewById(R.id.multiAutoCompleteTextView);
        buttonSubmit= (Button) findViewById(R.id.button);

        ArrayAdapter adapterCountries
                = new ArrayAdapter(this,android.R.layout.simple_list_item_1,countries);

        textCountry.setAdapter(adapterCountries);

        // Set the minimum number of characters, to show suggestions
        textCountry.setThreshold(1);

        ArrayAdapter adapterLanguages
                = new ArrayAdapter(this,android.R.layout.simple_list_item_1,languages);

        textProgrammingLanguage.setAdapter(adapterLanguages);

        textProgrammingLanguage.setThreshold(1);

        // The text separated by commas
        textProgrammingLanguage.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());

        buttonSubmit.setOnClickListener(new Button.OnClickListener(){

            @Override
            public void onClick(View v) {
                submitForm();
            }
        });
    }

    private void submitForm() {
        String text="Fullname: "+ this.textFullname.getText().toString()
                +"\nCountry: "+ this.textCountry.getText().toString()
                +"\nLanguages: "+ this.textProgrammingLanguage.getText().toString();

        Toast.makeText(this, text,Toast.LENGTH_LONG).show();

    }

}