property not visible outside of interface on iPhone app - objective-c

Question

I have a view controller, which creates 2 view controllers inside it. Inside each of these child controllers I wanted to create a property, which would be public, and accessible from the parent controller.
I am using the following method
TableViewController.h
#interface TableViewController : UITableViewController {
NSInteger projectId;
}
#property NSInteger projectId;
TableViewController.m
#implementation TableViewController
#synthesize projectId;
...
#end
I was then expecting the parent view controller to be able to create the child and access the parentId variable:
ParentViewController.h
#import "TableViewController.h"
#interface ParentViewController : UIViewController {
TableViewController* tableViewController;
}
#property (nonatomic, retain) TableViewController* tableViewController;
ParentViewController.m
#implementation ParentViewController
- (void)viewDidLoad {
self.tableViewController = [[TableViewController alloc] initWithNibName:#"TableViewController" bundle:nil];
self.tableViewController.projectId = 100;
}
However, the property projectId is not found, and returns the error - Request formember 'projectId'in something not a structure or a union.
If I change the line
self.tableViewController.projectId = 100;
to
[self.tableViewController setProjectId:100];
I get the warning - 'TableViewController' may not respond to '-setProjectId'
I am compiling this within XCode 4 preview 2, but also have the same issue within XCode 3.2
I am obviously missing something obvious, but cannot work out what it is.
Why can I not access this property?

Answer 1

Did you #import your .h files in the corresponding .m files?

Answer 2

Turns out that I had 2 copies of the TableViewController files. One had all my changes, the other was empty. I had initially created the file in the wrong directory and when I deleted it I had just removed it from the project.
Once I deleted these bogus files, everything worked fine.
Silly me!