android--Getting Started

learning the fundamental components

Before we discuss more detail about this framework, we will briefly cover some fundamental concepts we should know. It is very fundamental, but fundamental is most important.

View: user interface elements such as a button or a label that form the basic building blocks of a user interface. In short, it is called UI.

Activity: an activity represents a single screen in your application, something that helps the user do one thing.Most Android applications have several activities within them,

Intent: you can understand intent by following examples:

  • Broadcast a message
  • Start a service
  • Launch an activity
  • Display a web page or a list of contacts
  • Dial a phone number or answer a phone call
         So an Intent generically defines an "intention" to do some work.

Content Provider: Data sharing among different mobile applications, so through content providers, you can expose your data and have your applications use data from other applications.

Service: just like service in windows, they are background processes that can potentially run for a long time. Android defines two types of services: local services and remote services. If the service is owned by only one app, it's a local service. If several applications use the service, then it  would be implemented as a remote service.

Android Manifest.xml: it defines the contents and behavior of your application. For example, it lists your application's activities and services , along with the permissions and features the application needs to run.

Android Virtual Devices: AVD allows developers to test their applications without hooking up an actual Android device.



原文地址:https://www.cnblogs.com/suzhou/p/3638976.html