Android Development masterclass

On-device debugging
Although you can use the device emulator for development, you will still need to test your software on a real Android device to help you monitor your application’s real-world performance. While most Android devices can be used for on-device debugging, it is often disabled by default for security reasons. To enable it,  go to the device’s home screen, press Menu, select Applications>Development, then enable USB debugging.

Installing APK files
.apk is the extension for Android application package files (APKs). Each Android application is compiled and packaged in a single file that includes all of the application’s code (.dex files), resources, assets and the manifest file. The APK file is created while building the application. This file is deployed automatically to the device while debugging. At times you may want to install this file manually. To install the APK file manually, you can use either of the
following methods…
Using adb (Android Debugging Bridge):

$ adb install <.apk file>

To do the same thing on the device, copy the desired APK file onto the memory card. Search the Android Market for Apps Installer and install it. Now open the Apps Installer and It will show you all the APK files stored directly in the root directory of your memory card. Click on an APK file to install the relevant application.

Updating the Android SDK
Recently Google has introduced an easy-to-use method to keep the SDK current with the latest OS release. This tool is called the Android SDK and AVD Manager. It exists in the form of a command-line tool called android, found in the <SDK_HOME>/tools directory. To update the Android SDK, start Android SDK and AVD Manager. Go to Installed Packages and click the ‘Update All…’ button. You can also install new SDK releases by going to the Available Packages section.

Building an application for different screen sizes
One of the nice things about Android is that any device manufacturer can use it to create a range of devices. Android does not detect the size of the screen size to use. Hence you will find a plethora of different screen sizes available on Android devices. It is expected that your application will work well with all Android devices irrespective of the device screen size and resolution.