Should I get instances of classes in onResume() or onCreate()

Question

My intuition says to do it once in onCreate() , but I am not sure if there is some advantage to having a fresh instance each time. What's the best practice here?

Answer 1

We need some more context to give you a straight answer. Both methods might be called multiple times depending on what the user is doing.

I suggest defaulting your object instances as null, and inside onCreate() and/or onResume() , initialize it only if it is null.

if(objectInstance == null)
{
    objectInstance = new MyObject();
}

Answer 2

You should not re instantiate an object that you already have unless you have a reason for it! recreating objects just gets more memory and produces more garbage for the GC that is bad for efficiency!

So initialize needed objects in onCreate()

Answer 3

Like Hojjat points out you should not re instantiate objects, you must create again the objects if they are not currently present,

if(myObject == null){
    myObject = new ObjectFoo();
}

but if you are using a service maybe that will require the initialization:

class A extends Activity{
    public ServiceClass mService = null; // service objecct
    public void onCreate(){
        mService = new ServiceClass();
    }

    public void onResume(){
        mService.methodA();
    }
}