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