Putting it simply:
As the name suggests, it’s the context of the current state of the application/object. It lets newly-created objects understand what has been going on. Typically you call it to get information regarding another part of your program (activity and package/application).
You can get the context by invoking getApplicationContext()
, getContext()
, getBaseContext()
or this
(when in a class that extends from Context
, such as the Application, Activity, Service and IntentService classes).
Typical uses of context:
-
Creating new objects:
Creating new views, adapters, listeners:TextView tv = new TextView(getContext()); ListAdapter adapter = new SimpleCursorAdapter(getApplicationContext(), ...);
-
Accessing standard common resources:
Services like LAYOUT_INFLATER_SERVICE, SharedPreferences:context.getSystemService(LAYOUT_INFLATER_SERVICE) getApplicationContext().getSharedPreferences(*name*, *mode*);
-
Accessing components implicitly:
Regarding content providers, broadcasts, intentgetApplicationContext().getContentResolver().query(uri, ...);