Why UIScrollView don't scroll?

Question

I have a UIScrollView, inside which I have some UILabels and a UITextView. The UIScrollView is a subview of a master UIView. The UIScrollView is initialized as:

UIScrollView* scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(30, 75, rct.size.width-50, 1000)];

The UILabels are added to it as subviews:

    lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 200, 20)];
    lbl.textColor = [UIColor whiteColor];
    [lbl setBackgroundColor:[UIColor greenColor]];
    [lbl setFont:[UIFont fontWithName:@"Arial-BoldMT" size:16]];
    lbl.text = [NSString stringWithFormat:@"name: %@",firstName];
    [scrollView addSubview:lbl];
    [lbl release];

    lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 20, 200, 40)];
    lbl.textColor = [UIColor whiteColor];
    [lbl setBackgroundColor:[UIColor redColor]];
    [lbl setFont:[UIFont fontWithName:@"Arial-BoldMT" size:16]];
    lbl.text = [NSString stringWithFormat:@"last name: %@",lastName];
    [scrollView addSubview:lbl];
    [lbl release];

    .   
    .   

    // TEXT VIEW

    UITextView *txt1 = [[UITextView alloc] initWithFrame:CGRectMake(0, 160, rct.size.width-50, 1000)];
    txt1.textAlignment = UITextAlignmentLeft;
    txt1.textColor = [UIColor whiteColor];
    [txt1 setBackgroundColor:[UIColor clearColor]];
    UIFont *f = [UIFont fontWithName:@"Arial-BoldMT" size:16];
    [txt1 setFont:f];
    txt1.text = [NSString stringWithFormat:@"info: %@",personInfo];
    [scrollView addSubview:txt1];

    CGRect newframe1 = txt1.frame;
    newframe1.size.height = txt1.contentSize.height + 3; // offset for shadow
    txt1.frame = newframe1;
    [txt1 release];

The TextView is added as a hack (shown here), and is basically the only one scrollable, the other views remain static, I need them to scroll as well.

EDIT: When I add a UILabel even outside the bounds of the scrollView it won't scroll there:

    lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 940, 100, 1000)];
    lbl.textColor = [UIColor whiteColor];
    [lbl setBackgroundColor:[UIColor whiteColor]];
    [lbl setFont:[UIFont fontWithName:@"Arial-BoldMT" size:20]];
    lbl.text = [NSString stringWithFormat:@"TEST"];
    [scrollView addSubview:lbl];
    [lbl release];

The scrollView won't budge!

You need to set the scrollView's contentSize. Also, you should consider using ARC (Automatic Reference Counting), as this will make your app more reliable. — Andreas Ley

sergio sergio · Accepted Answer · 2012-10-19T12:03:27

You should try and set the contentSize of your scroll view:

scrollView.contentSize = ...

to something bigger than the scroll view frame. (say, something containing the label and the text view, maybe 1160 pixel high).

The frame of the scroll view should be set to represent the size of the visible area in the scroll view not the full size of the scroll view content.

Why UIScrollView don't scroll?

1 Answers