Thursday, June 21, 2012


A service is an application component that can perform long-running operations in the background and does not provide a user interface. Another application component can start a service and it will continue to run in the background even if the user switches to another application. Additionally, a component can bind to a service to interact with it and even perform interprocess communication (IPC). For example, a service might handle network transactions, play music, perform file I/O, or interact with a content provider, all from the background


View is the base class for widgets, which are used to create interactive UI components (buttons, text fields, etc.). All of the views in a window are arranged in a single tree. You can add views either from code or by specifying a tree of views in one or more XML layout files. There are many specialized subclasses of views that act as controls or are capable of displaying text, images, or other content.
The base LayoutParams class just describes how big the view wants to be for both width and height. For each dimension, it can specify one of:

  • an exact number
  • MATCH_PARENT, which means the view wants to be as big as its parent (minus padding)
  • WRAP_CONTENT, which means that the view wants to be just big enough to enclose its content (plus padding).
  • Example For ListView Using BaseAdapter

    Above is an example of ListView in android which extends BaseAdapter. Here we are inflating Layout to ListView.

    public class ListExample extends ListActivity {

    private ArrayList<String> dataname = new ArrayList<String>();
    private ArrayList<String> datacode = new ArrayList<String>();
    Context con = this;

    Wednesday, June 13, 2012


    Dalvik Debug Monitor Service, a GUI debugging application shipped with
    the SDK. It provides screen capture, log dump, and process examination


    A class (Intent) describes what a caller desires to do. The caller
    sends this intent to Android's intent resolver, which finds the most
    suitable activity for the intent. E.g. opening a PDF file is an
    intent, and the Adobe Reader is the suitable activity for this inten

    Android application package file (APK)

    Android application package file (APK) is the file format used to
    distribute and install application software and middleware onto
    Google's Android operating system. To make an APK file, a program for
    Android is first compiled, and then all of its parts are packaged into
    one file. This holds all of that program's code such as (.dex files),
    resources, assets, certificates, and manifest file. As is the case
    with many file formats, APK files can have any name needed, but must
    end with the four character, three letter extension, .apk.[1][2][3][4]
    APK files are ZIP file formatted packages based on the JAR file format.

    Android Debug Bridge

    Android Debug Bridge, a command-line debugging application shipped with the SDK. It provides tools to browse the device, copy tools on the device, and forward ports for debugging. Android Debug Bridge. A tool used to connect and sends commands to your Android phone from a desktop or laptop computer.

    Android Application Architecture

    1. Services - like Network Operation
    2. Intent - To perform inter-communication between activities or services
    3. Resource Externalization - such as strings and graphics
    4. Notification signaling users - light, sound, icon, notification, dialog etc.
    5. Content Providers - They share data between applications