Button Tutorial: Android Programming HD

Demonstration on how to create a button in an Android application. Walks through creating the button and writing the Java code to make it interactive. Steps and Java code included below in this description. Steps =============== 1. Create the button on the UI (xml). 2. Get a reference to the button (java) 3. Register a listener (java) [code below]: myButton.setOnClickListener(...) Our listener is an anonymous class implementing: View.OnClickListener We implement its only function: onClick() (this is where we put our code). Aside: Toast: a message that pops up on the screen. Java Code: ============================== public class MainActivity extends Activity { private final String TAG = "DemoButtonApp"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); setupMessageButton(); } private void setupMessageButton() { // 1. Get a reference to the button. Button messageButton = (Button) findViewById(R.id.btnDisplayMessage); // 2. Set the click listener to run my code. View.OnClickListener myListener = new View.OnClickListener() { @Override public void onClick(View v) { Log.i(TAG, "You clicked the button!"); Toast.makeText( MainActivity.this, "You clicked it!", Toast.LENGTH_LONG ).show(); } }; messageButton.setOnClickListener(myListener); } } Demo created using the Android Development Tools, build v21.0.0-519525