iOS表格视图和视图控制器

Question

I am trying to write my first iPad app, and I have a problem.

I have my Main view controller with a button. Once the button is pressed, it requests a list of information from a web server, and returns the data. This data, I want to put into a table view in a popover.

I have the main view controller, and the data is received back and put into a dictionary, then that is looped through to get a couple of arrays of data. I also have a Popover view controller that can display a static table view.

My question is, how do I get the data (either the dictionary, or the arrays) from the Main view controller to the Popover view controller?

I am really lost.

Thanks

James

Answer 1

There are two design patterns you have to keep in mind: delegation and notification . in a more general way also KVO is useful to update your view if the model changed. Of course the object listening for notifications or acting as a delegate is the controller of that view, NEVER the view itself.

There are two things you want to avoid at any time: storing stuff in global variables or in singletons and making "super objects" that act as let us say the model and the controller. Stick to the MVC paradigm and try to loose couple your objects and think about which object owns which other object. This is important for memory management and if you not implement it correctly it will come back to you later.

Check out session #116 - Model-View-Controller for iPhone OS from WWDC10 session videos and session #123 - iPhone View Controller Techniques from WWDC09.

The WWDC10 videos are available for free at apple's developer site.

Answer 2

Hey James, I suggest you first do your homework and try to get a taste on how so-called delegate structure works in most iOS apps.

To be more clear, your main view controller would become the delegate and your popover view controller would become the child of such a delegate. The delegate is responsible for presenting its child controller. At the same time, the child controller is responsible for asking for data from and reporting any changes to its delegate controller.

So in this way your popover controller can get the data it wants from your main view controller, and at the same time, when the user wants to dismiss the popover view, the popover view controller detects the user's instructions and informs the main view controller to dismiss it.

Answer 3

have described another possibility a few seconds ago:

Passing array between view controllers?