How to execute code after Activity creation in Android?

Question

I want to execute some code immediately after the form is shown.

I want to check the size of a button on the form and use the same size to create a new button at runtime.

I tried onStart() and onResumed(), but they do not work.

Thanks, Ashok

I think you are not looking for when the activity is created, but the layout is built. I have not dealt with that, but [this](http://stackoverflow.com/questions/8418868/how-to-know-when-an-activity-finishes-a-layout-pass) seems a good place to start. — MalaKa, Sep 08 '14 at 16:29
You can post a `Runnable` on it. [See this answer](http://stackoverflow.com/questions/18283686/listview-footer-at-the-bottom-of-screen/18283819#18283819) — codeMagic, Sep 08 '14 at 16:33

score 3 · Accepted Answer · answered Sep 08 '14 at 16:33

3

You can add a globallayout listener. Add the listener at onActivityCreated. Check this example:

button1.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                @Override
                public void onGlobalLayout() {
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                       button1.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                    } else {
                        button1.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                    }
                   //here the size is already available. create new button2 here with the size of button1
                }
            });

answered Sep 08 '14 at 16:33

Pedro Oliveira

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I will try this later today. – AndroidAshok Sep 08 '14 at 16:38
Just want to make sure this: would above code run only once? I can manage even if it runs multiple times. Thanks – AndroidAshok Sep 08 '14 at 17:00
If you remove the listener the code will only run once. Notice the first 4 lines used to remove the listener. – Pedro Oliveira Sep 08 '14 at 17:02
Oh, I got it. It was obvious but I missed it. Thanks for pointing out. – AndroidAshok Sep 08 '14 at 19:50

score 0 · Answer 2 · answered Sep 08 '14 at 16:33

0

you are looking at the onCreate() method, that is the function that will run when your app is first loaded in to memory

answered Sep 08 '14 at 16:33

mpop

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The layout information such as size won't be available yet – codeMagic Sep 08 '14 at 16:34
The layout will be avalable after you call the setContentView(R.layout.) – mpop Sep 08 '14 at 16:38
I understand it now. Thanks – AndroidAshok Sep 08 '14 at 16:38
@mpop There will be access to the `Views` but no guarantee that they have been completely measured so the size, most likely, won't be available yet just because you call `setContentView()` – codeMagic Sep 08 '14 at 16:40

How to execute code after Activity creation in Android?

2 Answers2