UIScrollView not scrolling

It's always good to show a complete working code snippet:

// in viewDidLoad (if using Autolayout check note below):

UIScrollView *myScrollView;
UIView *contentView;
// scrollview won't scroll unless content size explicitly set

[myScrollView addSubview:contentView];//if the contentView is not already inside your scrollview in your xib/StoryBoard doc

myScrollView.contentSize = contentView.frame.size; //sets ScrollView content size

Swift 4.0

let myScrollView
let contentView

// scrollview won't scroll unless content size explicitly set

myScrollView.addSubview(contentView)//if the contentView is not already inside your scrollview in your xib/StoryBoard doc

myScrollView.contentSize = contentView.frame.size //sets ScrollView content size

I have not found a way to set contentSize in IB (as of Xcode 5.0).

Note: If you are using Autolayout the best place to put this code is inside the -(void)viewDidLayoutSubviews method .

If you cannot scroll the view even after you set contentSize correctly, make sure you uncheck "Use AutoLayout" in Interface Builder -> File Inspector.

You need to set the contentSize property of the scroll view in order for it to scroll properly.

If you're using autolayout, you need to set contentSize in viewDidLayoutSubviews in order for it to be applied after the autolayout completes.

The code could look like this:

-(void)viewDidLayoutSubviews
{
    // The scrollview needs to know the content size for it to work correctly
    self.scrollView.contentSize = CGSizeMake(
        self.scrollContent.frame.size.width,
        self.scrollContent.frame.size.height + 300
    );
}

The answer above is correct - to make scrolling happen, it's necessary to set the content size.

If you're using interface builder a neat way to do this is with user defined runtime attributes. Eg:

Try to resize the content size to huge numbers. I couldn't understand why my scroll view doesn't scroll even when its content size seems to be bigger than control size. I discovered that if the content size is smaller than needed, it doesn't work also.

self.scrollView.contentSize = CGSizeMake(2000, 2000);

Instead of 2000 you can put your own big numbers. And if it works, it means that your content size is not big enough when you resize.

The delegate is not necessary for scroll view to work.