A question about UIVIEW Tags objective-c

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+1 Q:

A question about UIVIEW Tags objective-c

I have a question about tags for UIViews. Is it possible to create your own tag like myview.tag="main" or something like that?

I'm asking because my views are created in code and not with a nib file. After the container view has loaded and an xml file is fully parsed I need to be able to get at the subviews and update values.

After a bit of digging around I read that using viewWithTag would be a good way to do this

+3 A:

Yes you can do that in your code and it is a common technique.

However, UIView-tag is an integer. So you might want to enum or define something readable e.g. #define kMySuperViewTag 1 or enum { kMySuperViewTag, kMyNotSoSuperViewTag, ...};

Till 2010-02-22 13:49:02

hey cool, thanks.And how do I associate the tab with a view?

dubbeat 2010-02-22 13:53:50

myView.tag = kMySuperViewTag; //(using defines or enums as explained)

Till 2010-02-22 13:55:04

mega! Thanks alot

dubbeat 2010-02-22 13:56:01

hmmmmm.....I can access my tabbarcontroller view no problem. When I try to get at one of its sub views my apps crashes UITabBarController *tabbar = nil; PromoTabOptionHome *home=nil; tabbar = (UITabBarController *)[self.view viewWithTag:79]; home=(PromoTabOptionHome *)[tabbar.view.subviews objectAtIndex:0]; //this line cause crash home.avatarPath=@"a test string";

dubbeat 2010-02-22 14:24:26

Referring to your crash-problem; use the debugger:Set a breakpoint after that tabbar=...-line. Once the debugger stopped your application, go into the GDB-console and enter: "po tabbar". Is that object actually what you expected it to be? If the above has no surprising results, I would guess that your tabbar does not have any subviews attached at that moment.

Till 2010-02-22 14:42:30

I figured out why it was crashing. My "PromoTabOptionHome" is actually a viewController not an actual view. I changed code to this and it worked UITabBar *tabbar = nil; UIView *home=nil; tabbar = (UITabBar *)[self.view viewWithTag:79]; tabbar.alpha=0.5; home=(UIView *)[tabbar.subviews objectAtIndex:0];.The problem now is I have access to the view I want but I cant access the methods in its controller like I wanted. Can I refer to the controller from some property of the view? E.G view.UIIController

dubbeat 2010-02-22 15:41:36

Referring to your access UIViewController from inside its UIView; that is not supported by the plain UIView. If you insist on working that way you need to subclass UIView and add a reference to its UIViewController to it. Personally I find such construct not clever and would discourage its use as you were trashing reusability and creating strong dependencies on the UIView/UIViewController pairing. My rule of thumb: avoid accessing parent-objects from its childs if possible by any means. Certainly there are things were such construct makes sense but usually that is just sloppy coding.

Till 2010-02-22 19:30:55

Ok, thanks very much for all of your advice. I reckon I should rethink how my code is working and do a little restructuring.

dubbeat 2010-02-23 08:19:44

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