Android: how can fragment take a global variable of Activity

Question

I have an activity with a global variable int x, how can a fragment get the current value of variable x of its activity ?

score 94 · Accepted Answer · edited Sep 11 '12 at 07:06

94

Either set the var as public static, or use

((MyActivity)getActivity()).getX()

edited Sep 11 '12 at 07:06

hsz

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answered Sep 11 '12 at 07:05

Steelight

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Setting the variable as `static` (like I had been doing) apparently causes a memory leak, according to an Android Studio lint warning. I'm going to use the latter approach. – Farbod Salamat-Zadeh Oct 14 '16 at 21:34
How to do this in Kotlin? – Narendra Singh Dec 08 '17 at 10:51
i was already using public static. problem was i was getting json data using volley. so i was trying to get view before data returned. i dont know what is memory lead anyhow. thanks – MindRoasterMir Apr 13 '19 at 09:47
Doesn't this tightly couple the activity with the fragment, limiting flexibility and reusability? – Zorayr Nov 05 '20 at 21:19

Suragch · Answer 2 · 2017-06-08T06:03:45.040

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Using a public static variable isn't the best way to communicate between an activity and a fragment. Check out this answer for other ways:

The Android documentation recommends using an interface when the Fragment wants communicate with the Activity. And when the Activity wants to communicate with the Fragment, the Activity should get a reference to the Fragment (with findFragmentById) and then call the Fragment's public method.

The reason for this is so that fragments are decoupled from the activity they are in. They can be reused in any activity. If you directly access a parent Activity or one of its global variables from within a fragment, you are no longer able to use that fragment in a different Activity.

edited Jun 08 '17 at 06:03

answered Sep 11 '14 at 11:24

Suragch

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but why can't you use the fragment in different activity if we do this. – ams92 Nov 18 '18 at 01:03
@ams92, Because the fragment would still have a dependency on the old activity. You would have to change the fragment code every time that you wanted to use it in a new activity. – Suragch Jan 11 '19 at 16:55

score 12 · Answer 3 · answered Jun 19 '18 at 11:27

12

Kotlin version:

(activity as MyActivity).x

answered Jun 19 '18 at 11:27

Manohar

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score 4 · Answer 4 · answered Dec 04 '17 at 06:34

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***In your Activity
==================
Bundle args = new Bundle();
args.putInt("something", Whatever you want to pass);
fragA.setArguments(args);

In your Fragment
==================
 Bundle args = getArguments();
//whatever you want to get ,get it here.
//for example integer given     
    int index = args.getInt("index", 0);

answered Dec 04 '17 at 06:34

Kartheek

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After creating your fragment that needs to be done in your activity – Kartheek Dec 05 '17 at 05:31

Android: how can fragment take a global variable of Activity

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