How To Create AutoCompleteTextView

How To Create AutoCompleteTextView in Android Studio

The result will show as below screen.

Step 1 : layout have to create a AutoCompleteTextView with id "ac_student".
Layout Name : activity_main.xml

<?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">

    <AutoCompleteTextView        

       android:id="@+id/ac_student"        

       android:layout_width="match_parent"       

       android:layout_height="wrap_content"        

       app:layout_constraintEnd_toEndOf="parent"        

       app:layout_constraintStart_toStartOf="parent"        

       app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

Step 2 : Java class add in following:
1. String arrays for "studentList" consist of studentA, studentB, studentC, studentD & studentE.
2. Create a new ArrayAdapter and assigned the "studentList".
3. Declare AutoCompleteTextView and find id from the activity_main.xml.
4. SetThreshold to 1 will start working from first character.

String[] studentList ={"studentA","studentB","studentC","studentD","studentE"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>
        (this,android.R.layout.select_dialog_item,studentList);

AutoCompleteTextView actv =  (AutoCompleteTextView)findViewById(R.id.ac_student);

actv.setThreshold(1);

actv.setAdapter(adapter);

THE END. HAPPY CODING. :)