Getbasecontext (), Getapplication (), Getapplicationcontext ()

Activity is actually A subset of the application context contexts.

Subclasses have something that the parent does not necessarily have

There must be something in the parent class.

Getapplicationcontext (); long life cycle, as long as the application has survived it exists;

This short life cycle, as long as the Activity does not exist, the system will be recycled;

Among them: Getbasecontext (), Getapplication (), Getapplicationcontext ();

Can not be placed in the context of alertdialog ;

Getapplicationcontext() Usage scenarios such as databases that require frequent operations

Getbasecontext (), Getapplication (), Getapplicationcontext ()