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Android Android Fragments Introducing Fragments Handling Clicks

Sexual Potatoes
Sexual Potatoes
12,051 Points
Posted by Sexual Potatoes
Sexual Potatoes
12,051 Points

Why do we need to go back to the ListFragment class, get the activity and cast it onto the interface?

I didn't understand the reasoning behind anything past creating the interface and implementing it correctly in MainActivity.java. There wasn't much of an explanation either. What role does this part play in the process ?

1 Answer

Elias Caceres
Elias Caceres
8,454 Points
Elias Caceres
Elias Caceres
8,454 Points

You want to send a message to MainActivity from ListFragment.

You can't just do something like

MainActivity.doSomeMethod()

Instead, using an Interface is one way of creating a communication tunnel (one way) from Fragment to MainActivity. You cast the Interface with 

getActivity()

because you need to specify which activity should recieve the message/callback.

Remember, this is only communication FROM Fragment TO MainActivity. If you want to communicate from MainActivity to Fragment, you will need to do something else, like use the FragmentManager.