Learning Android™ Application Programming: A Hands-On Guide to Building Android Applications

Creating Button Event Handlers

To make the buttons do something, you need to add event handlers to the buttons that detect when they are clicked, and you need to supply the method to be called. There are several ways of doing this with the Android SDK, but first let’s take the simple approach and add the handlers to the layout.

1. Open the activity_timer.xml layout file, and locate the two buttons you added earlier. Add the two click handlers to the appropriate buttons by setting android:onClick to the name of the methods you want called when the buttons are clicked. Call the two methods clickedStart and clickedStop, as shown in Listing 4.3.

Listing 4.3 Adding Click Handlers to Two Buttons

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<Button    android:id ...