Android Basic activity four startup modes

This thing is the most basic, found that they actually did not really try to do a good research

Standard: Default,

Singletop: Basically the same standard, but when the activity instance is already at the top of the task stack and no longer creates a new instance, it calls the Onnewintent method of that instance

Singletask: Unlike Singletop, no matter whether an activity instance is at the top of the stack, no new instance is created, but the instance in the stack is called onnewintent, and Cleartop

SingleInstance: This is very special, equivalent to the activity of a stack,

If there is ABC three activity, sequential start, B is singleinstance,ac default, then there will be the following phenomenon:

A->b->c, this time press RETURN, destroy order will be c->a->b

A->b->c->a->b->c, this time press RETURN, destroy order will be c->a->c->a->b

Android Basic activity four startup modes