What is ‘Context’ on Android?

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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, intent

     getApplicationContext().getContentResolver().query(uri, ...);

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