UIView - UIScrollView odd behaviour - ios

Question

I have a UIViewController named MenuViewController in which i create an UIView MessageView and pass it a NSString:
MessageView *mess = [[MessageView alloc]initWithFrame:CGRectMake(0, 0, 1024, 768)];
[mess messageString:#"A:text\nM:text\nA:text\nM:text"];
[self.view addSubview:mess];
In MessageView i am creating an UIScrollView and several UILabels; my problem is the following and i can't understand the behaviour:
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(540, 50, 360, 160)];
scrollView.backgroundColor = [UIColor redColor];
[self addSubview:scrollView];
}
return self;
}
- (void)messageString:(NSString *)string
{
UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(scrollView.frame.origin.x, scrollView.frame.origin.y, scrollView.frame.size.width, scrollView.frame.size.height/6)];
>>>>> HERE is the problem <<<<<<
if i try to add label to scrollView it does not appear
[scrollView addSubview:label];
if i try to add label to self it appears
[self addSubview:label];
}
I would like to create all of the content i would like to show here in MessageView and just call it from the view controller. Does anybody have an idea of what may be the problem ?

Answer 1

This line:
UIImageView *label = [UILabel alloc]initWithFrame:CGRectMake(scrollView.frame.origin.x, scrollView.frame.origin.y, scrollView.frame.size.width, scrollView.frame.size.height/6)];
Should be producing an error and a warning. For one, you're missing a starting bracket [, and on top of that, you're creating a pointer to a UIImageView object, and then assigning a label to it. Try again with the line written out like this:
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(scrollView.frame.origin.x, scrollView.frame.origin.y, scrollView.frame.size.width, scrollView.frame.size.height/6)];
This is of course assuming that the method is even being called, and the scroll view is non-nil and has a proper frame when you try to access it.

Answer 2

You are adding the label outside of scrollview's visible frame: Replace
UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(scrollView.frame.origin.x, scrollView.frame.origin.y, scrollView.frame.size.width, scrollView.frame.size.height/6)];
with
UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0,0, scrollView.frame.size.width, scrollView.frame.size.height/6)];