Dynamically added subviews in a UIScrollView not appearing - iphone

Question

I'm having a lot of trouble dynamically adding subviews to a UIScrollView. The scroll view works fine with content created in a NIB but since the subviews to be displayed depend on data in my application (a mixture of images, labels, radio buttons, etc.) I need to be able to create and display them dynamically.
According to everything I've read it seems pretty straightforward on various sites and in the Apple documentation. In the view controller's viewDidLoad, I've added the following code,
UILabel *testLabel = [[UILabel alloc] init];
[testLabel setFrame:CGRectMake(50, 50, 100, 40)];
[testLabel setText:#"My Test label"];
[scrollView addSubview:testLabel];
[testLabel release];
The label will not appear in the scroll view at all but if I add the testLabel to self.view, then it appears (but not in the scrolling content obviously). I even tried adding the code to viewDidAppear in case I misunderstood the order of events with no luck.
When I checked the debugger, I noticed that the address of the scroll view is 0x0 which I assume means its null for some reason which would explain why its not working. I was under the assumption that if I connected this scrollView pointer to the actual scroll view in IB, it would be automatically assigned the correct address. Is this incorrect? If this is the case, how do I go about getting the address of the view?
-- UPDATE --
Thanks for all the feedback. I checked everything as everybody suggested and it was certainly all correct. I didn't need to set the size of the content as I had some other dummy labels (for testing that the scrolling was working) in the NIB. But I'll remember that for later on :-)
Interestingly, though, after checking the code again and not making any changes, I ran it again and it just worked!! Not sure why but I'll post the reason if I ever figure it out...

Answer 1

When you use scrollView you need to set the content size by doing:
scrollView.contentSize = CGSizeMake(#width,#height);
In this case the size should be bigger the 50,50 if you wanna see the label
Hope it helped

Answer 2

As described in your question You are working with a scrollview which you have added in the XIB.
When you declare an outlet as IBOultlet UIScrollView* scrlvDynamicContent;
and connect the same to your scrollview in interface builder,ideally you will get the allocated scrollview after viewdidLoad method is called.
so doing something as
-(void)viewDidLoad{
[super viewDidLoad];
[self createDynamicView];
}
where you can generate the dynamic view as follows
-(void)createDynamicView{
CGFloat yOffset = 0;
for (int i=0;i<5;i++) {
yOffset += 5;
UILabel* lblHeaderTitle = [[UILabel alloc] initWithFrame:CGRectMake(8, yOffset, 310, 21)];
[lblHeaderTitle setTextAlignment:UITextAlignmentLeft];
[lblHeaderTitle setFont:[UIFont fontWithName:#"Helvetica-Bold" size:16.0f]];
[lblHeaderTitle setText:[currentDict valueForKey:#"TITLE"]];
[lblHeaderTitle setTextColor:[UIColor blackColor]];
[scrlvDynamicContent addSubview:lblHeaderTitle];
[lblHeaderTitle release];
//INCREMNET in yOffset
yOffset += 25;
[scrlvDynamicContent setContentSize:CGSizeMake(320, yOffset)];
}
Just make sure that scrlvDynamicContent is connected properly to its outlet set to its file owner

Answer 3

[scrollView setFrame:CGRectMake(0,0,320,460)];
[scrollView setContentSize:CGSizeMake(100, 40)];
[self.view addSubview:scrollView];
UILabel *testLabel = [[UILabel alloc] init];
[testLabel setFrame:CGRectMake(50, 50, 100, 40)];
[testLabel setText:#"My Test label"];
[scrollView addSubview:testLabel];
[testLabel release];