How to automatically size UIScrollView to fit the content

Or just do:

int y = CGRectGetMaxY(((UIView*)[_scrollView.subviews lastObject]).frame); [_scrollView setContentSize:(CGSizeMake(CGRectGetWidth(_scrollView.frame), y))];

(This solution was added by me as a comment in this page. After getting 19 up-votes for this comment, I've decided to add this solution as a formal answer for the benefit of the community!)

why not single line of code??

_yourScrollView.contentSize = CGSizeMake(0, _lastView.frame.origin.y + _lastView.frame.size.height);

Here is the accepted answer in swift for anyone who is too lazy to convert it :)

var contentRect = CGRectZero
for view in self.scrollView.subviews {
contentRect = CGRectUnion(contentRect, view.frame)
}
self.scrollView.contentSize = contentRect.size

Set dynamic content size like this.

self.scroll_view.contentSize = CGSizeMake(screen_width,CGRectGetMaxY(self.controlname.frame)+20);

Great & best solution from @leviathan. Just translating to swift using FP (functional programming) approach.

self.scrollView.contentSize = self.scrollView.subviews.reduce(CGRect(), {
CGRectUnion($0, $1.frame)
}.size

Because a scrollView can have other scrollViews or different inDepth subViews tree, run in depth recursively is preferable.
[![enter image description here][1]][1]


[1]:

**Swift 2**

extension UIScrollView {
//it will block the mainThread
func recalculateVerticalContentSize_synchronous () {
let unionCalculatedTotalRect = recursiveUnionInDepthFor(self)
self.contentSize = CGRectMake(0, 0, self.frame.width, unionCalculatedTotalRect.height).size;
}

private func recursiveUnionInDepthFor (view: UIView) -> CGRect {
var totalRect = CGRectZero
//calculate recursevly for every subView
for subView in view.subviews {
totalRect = CGRectUnion(totalRect, recursiveUnionInDepthFor(subView))
}
//return the totalCalculated for all in depth subViews.
return CGRectUnion(totalRect, view.frame)
}
}

**Usage**

scrollView.recalculateVerticalContentSize_synchronous()

Here's a Swift 3 adaptation of @leviatan's answer :

**EXTENSION**

import UIKit


extension UIScrollView {

func resizeScrollViewContentSize() {

var contentRect = CGRect.zero

for view in self.subviews {

contentRect = contentRect.union(view.frame)

}

self.contentSize = contentRect.size

}

}

**USAGE**

scrollView.resizeScrollViewContentSize()

Very easy to use !

For swift4 using reduce:

self.scrollView.contentSize = self.scrollView.subviews.reduce(CGRect.zero, {
return $0.union($1.frame)
}).size

Following extension would be helpful in **Swift**.

extension UIScrollView{
func setContentViewSize(offset:CGFloat = 0.0) {
// dont show scroll indicators
showsHorizontalScrollIndicator = false
showsVerticalScrollIndicator = false

var maxHeight : CGFloat = 0
for view in subviews {
if view.isHidden {
continue
}
let newHeight = view.frame.origin.y + view.frame.height
if newHeight > maxHeight {
maxHeight = newHeight
}
}
// set content size
contentSize = CGSize(width: contentSize.width, height: maxHeight + offset)
// show scroll indicators
showsHorizontalScrollIndicator = true
showsVerticalScrollIndicator = true
}
}

Logic is the same with the given answers. However, It omits hidden views within `UIScrollView` and calculation is performed after scroll indicators set hidden.

Also, there is an optional function parameter and you're able to add an offset value by passing parameter to function.

The best method I've ever come across to update the content size of a `UIScrollView` based on its contained subviews:

> **Objective-C**

CGRect contentRect = CGRectZero;

for (UIView *view in self.scrollView.subviews) {
contentRect = CGRectUnion(contentRect, view.frame);
}
self.scrollView.contentSize = contentRect.size;

> **Swift**

let contentRect: CGRect = scrollView.subviews.reduce(into: .zero) { rect, view in
rect = rect.union(view.frame)
}
scrollView.contentSize = contentRect.size