Android 9 Development Cookbook - Third Edition

How to do it...

We only need a single button for this example. Open activity_main.xml and follow these steps:

1. Replace the existing TextView with the following button:

<Button    android:id="@+id/buttonStart"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="Start"    android:onClick="start"    app:layout_constraintBottom_toBottomOf="parent"    app:layout_constraintLeft_toLeftOf="parent"    app:layout_constraintRight_toRightOf="parent"    app:layout_constraintTop_toTopOf="parent" />

2. Open MainActivity.java and add the following global variable:

Button mButtonStart; 

3. Add the AsyncTask class:

private class CountingTask extends AsyncTask<Integer, Integer, Integer> {    @Override    protected Integer doInBackground(Integer... ...