Can't edit any objects in method - iphone

Question

I have a weird problem. I have a tab bar application. When I wanna set the text of an UILabel in any method, there happens nothing.
For example, nothing happens with 'label1' when I call this method:
-(void)setOne:(NSMutableArray *)theArray {
label1 = [[UILabel alloc] init];
label1.text = #"Test";
}
Does anyone have a solution for this problem?
Thanks,
Jelle

Answer 1

When you call this method a new label is created and the connection to the label which was previously associated with this ivar is lost. This could also be a memory leak.
Edit:
Depending on the rest of your code, this could work:
-(void)setOne:(NSMutableArray *)theArray {
label1.text = #"Test";
}

Answer 2

You don't see anything happened because you create new instance of label and do not add it anywhere. If you really want to add new label to your view then create it with appropriate frame and actually add it to some view, e.g.
-(void)setOne:(NSMutableArray *)theArray {
label1 = [[UILabel alloc] initWithFrame:CGRectMake(10.0f, 10.0f, 200.0f, 30.0f)];
label1.text = #"Test";
[self.view addSubview: label1];
// And do not forget to release your label!
[label1 release];
}
If you want to change text of label that already exists do not create new instance in your method, just set new text to it:
-(void)setOne:(NSMutableArray *)theArray {
// if label1 already exists we don't need to create a new one
label1.text = #"Test";
}
Edit: (from more info in comments)
When you create view controller it may not load its view immediately so in your code
FirstViewController *FVC = [[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil];
[FVC setOne:[resultaten objectAtIndex:indexPath.row]];
when you call setOne method fvc's view may still not be loaded and label1 is still nil in that method. You can solve that forcing controller's view to load, the following should work:
FirstViewController *FVC = [[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil];
FVC.view;
[FVC setOne:[resultaten objectAtIndex:indexPath.row]];
But in general I'd suggest to store your values in some class that's independent from UI (i.e. Model) or at least in separate variable of your controller and set it to UI elements only when they actually loaded or appear on screen (in viewDidLoad or viewWillAppear methods)

Answer 3

- (void)viewDidLoad
{
[super viewDidLoad];
UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 200, 22)];
lbl.text =#"Hello";
[self.view addSubview:lbl];
}