Apps Create a new Activity or update view of existing activity?

[andypaul1]

I am very new to android development. I am working on developing an app and I am not sure when should I use a new activity and when should I update the existing view.

For example, lets say I have a view that shows a multiple choice question.Now, when the user selects his choices and clicks on say "Evaluate", I want to show the same question view but along with the right answers and explanations for each option. So does that mean, I should send an Intent upon a click on Evaluate or I should just update the view (i am not sure how)?

If I send an intent and show a new screen, how can the user go back to the next question without displaying the answers?
If I don't create an new activity, how can I update the existing view that is already displayed?

I guess I am just confused about the flow. Please pardon me if my question doesn't make any sense.

thanks!

 

[jonbonazza]

For your example, it would be best to use the same Activity, but just update the content of the Activity's Views.

Activities can generally be thought of as windows in a traditional window manager. They should be used to separate logical steps in an application's use.

 

[andypaul1]

Thank you for your suggestion, jon.
Any pointers on how to update an existing view that is already being displayed? I come from Java Swing world where I can simply add/remove components from a container in the event thread and the view is updated automatically. Or I just update the model (such as for a JTable) and call fireTableDataChanged, which updates the view.

How does this work in Android app? As I understand the view is described in a hardcoded XML file, so how do I update it dynamically?

thank you!

 

[jonbonazza]

You can really do the same thing in Android, but it is better practice to create all of the UIs up front and either show/hide various controls depending on the state, or simply create your layouts in seperate xml files and use the setContentView() method to swap between them.

 

[andypaul1]

ok, thank you again.