I am trying to get certain iVars from my view controller to my view (a subview) so drawrect will draw a shape based on user inputs. When I hard code those variables into the subview, the shape draws perfect, but when I use getters to access the custom variables from the view controller, they come back nil and the drawing is messed up. I get no errors or warnings. I know there is a problem with the getter, any suggestions? Anybody have an example of passing variables to a subview so cgcontext can be used in the drawrect? I am stuck big time. I assume at this point my problem is so simple, I am missing something fundamental. I thought I had setters/getters down packed.
A:
Make sure that whatever you're getting 'from' (ie, the parent, or view, or whatever you're accessing the getters on) is not nil. Try setting a break point right before accessing them and validating that your targets are valid, and have valid data.
Ben Gottlieb
2010-01-24 15:55:01
I know the ivars on the controller are not nil because they are used to set a label on said controller. Those labels are correct.
richieRich
2010-01-24 16:15:49
can you call the getters from the debugger? Are these properties or standard getter methods?
Ben Gottlieb
2010-01-24 16:47:59
Standard getter methods.
richieRich
2010-01-24 16:51:56
can you step into them in the debugger?
Ben Gottlieb
2010-01-24 17:30:01
I am not sure what you mean "step in".
richieRich
2010-01-24 17:37:26
using the debugger, can you break just before your getter gets called, and step into the code to see what's happening.
Ben Gottlieb
2010-01-24 19:28:31
I see, yes, I can use a breakpoint and step in now. Thanks for the help there. The iVars being got have the appropriate values at the breakpoint.
richieRich
2010-01-24 20:36:12
at this point, I think we're pretty much stuck without some code snippets.
Ben Gottlieb
2010-01-24 21:02:58
Does the view have to be a subclass of the viewcontroller? I can make it so, but it'll be a little work.
richieRich
2010-01-24 21:16:28
a view cannot be a subclass of UIViewController.
Ben Gottlieb
2010-01-24 21:39:28
Yeah, I found that out the hard way. Anyway thanks for the help. I'm gonna keep searching. The getter just doesn't get.
richieRich
2010-01-24 21:44:57
A:
We'd really need to see more code. Ben was saying that, somewhere in your view, you must set parent = (some code to get a reference to my parent). Make sure this actually works, i.e. you really do have a reference to your parent. Even if the ivars are correct, if your parent is nil, then sending [nil getSomeiVar] will return 0 in most cases.
Without a better understanding of the code, this is my guess. Somewhere in your UIViewController, you should have something like:
myView = //make your view
[myView setParent:self]
Parent is a variable of the view, with a property so that you can access it
Edit: Why does it matter if we know what you are making?
For setParent to work, you need to following:
- an ivar
YourUIViewControllerSubclass *parent;in your view's .h - a property for this ivar
@property (nonatomic, retain) YourUIViewControllerSubclass *parent;in your view's .h - A synthesis for this ivar
@synthesize parent;in your view's .m inside the@implementation
David Kanarek
2010-01-24 18:28:59
My app is too simple to post code. It'll be a dead give away what I am making.
richieRich
2010-01-24 18:35:28
It says the view does not respond to setParent. The viewcontroller doesn't either.
richieRich
2010-01-24 18:38:11
Did this help you any or can you give us some more info to try to figure it out?
David Kanarek
2010-01-25 00:00:46
A:
Yeah, you were both wrong, but I took a lot away from you helping me though. I didn't have to post code after all. I had to pick up my debugging skills big time. Someone in another post mentioned violations of the MVC. I had to set the ivars in the uiview, to the custom values FROM the view CONTROLLER. In other words, I had to set from the controller rather than getting from the subview.
richieRich
2010-01-25 00:25:49