Mastering Common Tasks of Android App Development
Android app development involves many tasks, including designing and building the core of your application; determining user interface components; and, importantly, making your Android app commercially available to the public. This table is a "how-to" for many of the tasks you perform when developing Android apps.
|Task||How to Accomplish|
|Create string, color, image, audio, and video resources||In the Android project look under the res directory. String and color resources are placed in the strings.xml file in the values sub-directory. Images, audio and video are added in the raw sub-directory.|
|Create icons||Icons are added in the drawable directories. Common icons are placed in res->drawable. Icons for specific screen resolutions and sizes are placed in the extended drawable directories; drawable-hdpi for high-resolution screens, drawable-mdpi for medium resolution screens and drawable-ldpi for low-res screens.|
|Create an activity||Create a Java class for the activity that extends android.app.Activity.Activity. Create an entry for it in the AndroidManifest.xml file.|
|Create the user interface for an activity||Create the layout file for each class in the res->layout directory. Use setContentView(...) to create and set the view for the activity. Use findViewById(...) to extract the components of the view. Activity must implement the onClickListener interface (the onClick(...) method).|
|Create a menu for an activity||Define the menu in the res-menu sub-directory of the project. Implement the onCreateOptionsMenu(Menu menu) method and the onOptionsItemSelected(MenuItem item).|
|Add logging to your application||Use Log.v(...), Log.d(...), Log.i(...), Log.w(...), or Log.e(...) (verbose, debug, information, warning, and error, respectively). Parameters to each of these methods are a string tag and a string message.|
|Launch a web browser from your app||Use:
Intent LaunchBrowserIntent = new Intent(Intent.ACTION_VIEW, theUri);
|Record audio or video||Create an intent using android.provider.MediaStore.Audio.Media.RECORD_SOUND_ACTION.
Broadcast the event using the startActivityForResult(...). Implement a
protected method onActivityResult(int
requestCode, int resultCode, Intent data) to receive the
result as an intent.
For video, use the same code, but with android.provider.MediaStore.ACTION_VIDEO_CAPTURE.
|Publish to the Android store.||Create a Developer account by clicking on the http://market.android.com/publish link at the bottom of the home page of the Android Market. Sign your application using File→Export→Android→Export Signed Android Application. Upload your application from the Developer Console of the Android Market.|