How to access to Class method from another Activity in Android?

Question

My app contains two classes: MainActivity, Activity2.
Activity2 needs to access a non-static method of MainActivity. How to do that?

I'm new with Java and Android, if you can, please explain clearly for beginners what to do.
Thanking you in advance.

there are so many examples in the web to learn the basics, just search it — kumar_android, Nov 30 '12 at 19:02

score 1 · Accepted Answer · answered Nov 30 '12 at 19:32

Instead of calling methods from a different activity you should use Bundles to pass values from ActivityA to ActivityB when B is started from A.

Alternatively if you want to reuse code you should create a non-activity object which you can create two instances of. Say if you do a lot of heavy calculations in both activities, you can put your calculating code in a "Calculate" object. And just initiate it like you would any other Java object. Just note that these two instance will not share any data between each other.

Calculate calc = new Calculate();
calc.codeIdLikeToReuse(numbersAndStuff);

Hope this helps. I would recommend that you read up on the Activity Life Cycle to get an idea on how the life on an activity is.

Thank you, I will read it (again) and try something with your suggestion. — Dennis, Nov 30 '12 at 20:43

score 0 · Answer 2 · answered Nov 30 '12 at 19:06

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Use Broad cast receiver to call methods in different activities you can find help here and one example

answered Nov 30 '12 at 19:06

Ali Imran

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score 0 · Answer 3 · answered Nov 30 '12 at 19:07

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Basically, you can't do that. Two activities don't communicate this way. Usually, only one activity is alive at a time (also this might not be always true). The real answer is to use Intents.

You should read some basic Android tutorial like the anddev book.

answered Nov 30 '12 at 19:07

Snicolas

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Thank you for helping! Actually, the method I want to call is showing a notification and I thought that it is wasteful to create the same method, with the same purpose - twice. – Dennis Nov 30 '12 at 20:41
Yes you are right, but that is something different. In that case, you should consider some inheritence or some composition (that's better). Give the method to another entity , and call it in both Activities. That is what @Hermith suggested by the way. – Snicolas Dec 01 '12 at 04:49
And read the book. It's really worth it, it was my first Android reading and really helped a lot to get the basics. – Snicolas Dec 01 '12 at 04:49

score 0 · Answer 4 · edited May 23 '17 at 12:34

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you also can use libraries like EventBus to link the code. refer to this post

edited May 23 '17 at 12:34

Community

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answered Nov 15 '16 at 07:23

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How to access to Class method from another Activity in Android?

4 Answers4