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I created a UIScrollView with its constraints set in storyboard, but I sometimes move the UIScrollView to a different position at runtime.
My problem happens when I create a custom UIView programmatically and add it the the main UIView. My constraints will update, and if my UIScrollView is not is the same location, it will be moved to the storyboard setting.
For instance, imagining my UIScrollView is pinned to the top of the screen, and then I move it to the bottom of the screen at runtime. If I execute this code:
let menu = UIView()
menu.frame.size = CGSize(width: 210, height: 80)
menu.center = view.center
view.addSubview(menu)
My UIScrollView will moved back to the tap on the screen. I try this but it did not work:
myScrollView.constraints.first?.isActive = false
When using auto-layout and constraints, you cannot change frames by setting the view.frame explicitly.
If you try to do so, then on the next UI update auto-layout will reset the view to its constraints.
If you need to move / size a view at run-time, you'll want to have a reference to the constraint(s) you've set, and then modify the constraint.
For example, if your scroll view is constrained 20-pts from the top of the view, and you want to move it down 50-pts at run-time...
create an IBOutlet for the top constraint
in code, use myTopConstraint.constant = 70.0
Using Storyboard, in UIViewController using UIScrollView, UIView as content view
Scrollview Constraints - top, bottom, left, right
UIView as contentview constraints - top, bottom, left, right, equal width height to ViewController's View.
I am using these constraints, can anyone please help me out why button is not calling?
The button is not clickable because it is below the frame of the content view. You need to remove all auto layout constraints from your content view (the UIView inside the scrollview).
Then you can add all the objects that you need to add to the content view and set the height of the content view according to the height of the content.
So lets say that you calculated a height of 1000 for the content of the objects in the scroll view. You would then need to set the frame of the content view like this:
contentView.frame = CGRectMake(0,0,scrollView.frame.size.width, 1000);
And don't forget to set the contentSize for the scrollview so that the scrollview knows how much room it needs to scroll.
Just now found the answer with removing any autolayout constraints, for content view we have to set constraints like below:
Top, bottom, left, right
Align CenterX - here we have to set the content view height then for that constraint we have to set constant as scrollview content size height
Let's say I have added more views in UIStackView which can be displayed, how I can make the UIStackView scroll?
In case anyone is looking for a solution without code, I created an example to do this completely in the storyboard, using Auto Layout.
You can get it from github.
Basically, to recreate the example (for vertical scrolling):
Create a UIScrollView, and set its constraints.
Add a UIStackView to the UIScrollView
Set the constraints: Leading, Trailing, Top & Bottom should be equal to the ones from UIScrollView
Set up an equal Width constraint between the UIStackView and UIScrollView.
Set Axis = Vertical, Alignment = Fill, Distribution = Equal Spacing, and Spacing = 0 on the UIStackView
Add a number of UIViews to the UIStackView
Run
Exchange Width for Height in step 4, and set Axis = Horizontal in step 5, to get a horizontal UIStackView.
I present you the right solution
For Xcode 11+
Step 1:
Add a ScrollView and resize it
Step 2:
Add Constraints for a ScrollView
Step 3:
Add a StackView into ScrollView, and resize it.
Step 4:
Add Constraints for a StackView (Stask View -> Content Layout Guide -> "Leading, Top, Trailing, Bottom")
Step 4.1:
Correct Constraints -> Constant (... -> Constant = 0)
Step 5:
Add Constraints for a StackView (Stask View -> Frame Layout Guide -> "Equal Widths")
Step 6 Example:
Add two UIView(s) with HeightConstraints and RUN
I hope it will be useful for you like
Apple's Auto Layout Guide includes an entire section on Working with Scroll Views. Some relevant snippets:
Pin the content view’s top, bottom, leading, and trailing edges to the scroll view’s corresponding edges. The content view now defines
the scroll view’s content area.
(Optional) To disable horizontal scrolling, set the content view’s width equal to the scroll view’s width. The content view now fills the
scroll view horizontally.
(Optional) To disable vertical scrolling, set the content view’s height equal to the scroll view’s height. The content view now fills
the scroll view horizontally.
Furthermore:
Your layout must fully define the size of the content view (except
where defined in steps 5 and 6). … When the content view is taller than the scroll view, the scroll view enables vertical scrolling. When the content view is wider than the scroll view, the scroll view enables horizontal scrolling.
To summarize, the scroll view's content view (in this case, a stack view) must be pinned to its edges and have its width and/or height otherwise constrained. That means that the contents of the stack view must be constrained (directly or indirectly) in the direction(s) in which scrolling is desired, which might mean adding a height constraint to each view inside a vertically scrolling stack view, for example. The following is an example of how to allow for vertical scrolling of a scroll view containing a stack view:
// Pin the edges of the stack view to the edges of the scroll view that contains it
stackView.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
stackView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor).isActive = true
stackView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor).isActive = true
stackView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true
// Set the width of the stack view to the width of the scroll view for vertical scrolling
stackView.widthAnchor.constraint(equalTo: scrollView.widthAnchor).isActive = true
Up to date for 2020.
100% storyboard OR 100% code.
This example is vertical:
Here's the simplest possible explanation:
Have a blank full-screen scene
Add a scroll view. Control-drag from the scroll view to the base view, add left-right-top-bottom, all zero.
Add a stack view in the scroll view. Control-drag from the stack view to the scroll view, add left-right-top-bottom, all zero.
Put two or three labels inside the stack view.
For clarity, make the background color of the label red. Set the label height to 100.
Now set the width of each UILabel:
Surprisingly, control-drag from the UILabel to the scroll view, not to the stack view, and select equal widths.
To repeat:
Don't control drag from the UILabel to the UILabel's parent - go to the grandparent. (In other words, go all the way to the scroll view, do not go to the stack view.)
It's that simple. That's the secret.
Secret tip - Apple bug:
It will not work with only one item! Add a few labels to make the demo work.
You're done.
Tip: You must add a height to every new item. Every item in any scrolling stack view must have either an intrinsic size (such as a label) or add an explicit height constraint.
The alternative approach:
To recap the above approach: surprisingly, set the widths of the labels to the width of the scroll view (not the stack view).
Here is an alternate approach...
Drag from the stack view to the scroll view, and add a "width equal" constraint. This seems strange because you already pinned left-right, but that is how you do it. No matter how strange it seems that's the secret.
So you have two options:
Surprisingly, set the width of each item in the stack view to the width of the scrollview grandparent (not the stackview parent).
or
Surprisingly, set a "width equal" of the stackview to the scrollview - even though you do have the left and right edges of the stackview pinned to the scrollview anyway.
To be clear, do ONE of those methods, do NOT do both.
The constraints in the top-voted answer here worked for me, and I've pasted an image of the constraints below, as created in my storyboard.
I did hit two issues though that others should be aware of:
After adding constraints similar to those in in the accepted answer, I'd get the red autolayout error Need constraints for: X position or width. This was solved by adding a UILabel as a subview of the stack view.
I'm adding the subviews programmatically, so I originally had no subviews on the storyboard. To get rid of the autolayout errors, add a subview to the storyboard, then remove it on load before adding your real subviews and constraints.
I originally attempted to add UIButtons to the UIStackView. The buttons and views would load, but the scroll view would not scroll. This was solved by adding UILabels to the Stack View instead of buttons. Using the same constraints, this view hierarchy with the UILabels scrolls but the UIButtons does not.
I'm confused by this issue, as the UIButtons do seem to have an IntrinsicContentSize (used by the Stack View). If anyone knows why the buttons don't work, I'd love to know why.
Here is my view hierarchy and constraints, for reference:
As Eik says, UIStackView and UIScrollView play together nicely, see here.
The key is that the UIStackView handles the variable height/width for different contents and the UIScrollView then does its job well of scrolling/bouncing that content:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
scrollView.contentSize = CGSize(width: stackView.frame.width, height: stackView.frame.height)
}
Horizontal Scrolling (UIStackView within UIScrollView)
For horizontal scrolling. First, create a UIStackView and a UIScrollView and add them to your view in the following way:
let scrollView = UIScrollView()
let stackView = UIStackView()
scrollView.addSubview(stackView)
view.addSubview(scrollView)
Remembering to set the translatesAutoresizingMaskIntoConstraints to false on the UIStackView and the UIScrollView:
stackView.translatesAutoresizingMaskIntoConstraints = false
scrollView.translatesAutoresizingMaskIntoConstraints = false
To get everything working the trailing, leading, top and bottom anchors of the UIStackView should be equal to the UIScrollView anchors:
stackView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor).isActive = true
stackView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor).isActive = true
stackView.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
stackView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true
But the width anchor of the UIStackView must the equal to or greater than the width of the UIScrollView anchor:
stackView.widthAnchor.constraint(greaterThanOrEqualTo: scrollView.widthAnchor).isActive = true
Now anchor your UIScrollView, for example:
scrollView.heightAnchor.constraint(equalToConstant: 80).isActive = true
scrollView.widthAnchor.constraint(equalTo: view.widthAnchor).isActive = true
scrollView.bottomAnchor.constraint(equalTo:view.safeAreaLayoutGuide.bottomAnchor).isActive = true
scrollView.leadingAnchor.constraint(equalTo:view.leadingAnchor).isActive = true
scrollView.trailingAnchor.constraint(equalTo:view.trailingAnchor).isActive = true
Next, I would suggest trying the following settings for the UIStackView alignment and distribution:
topicStackView.axis = .horizontal
topicStackView.distribution = .equalCentering
topicStackView.alignment = .center
topicStackView.spacing = 10
Finally you'll need to use the addArrangedSubview: method to add subviews to your UIStackView.
Text Insets
One additional feature that you might find useful is that because the UIStackView is held within a UIScrollView you now have access to text insets to make things look a bit prettier.
let inset:CGFloat = 20
scrollView.contentInset.left = inset
scrollView.contentInset.right = inset
// remember if you're using insets then reduce the width of your stack view to match
stackView.widthAnchor.constraint(greaterThanOrEqualTo: topicScrollView.widthAnchor, constant: -inset*2).isActive = true
I was looking to do the same thing and stumbled upon this excellent post. If you want to do this programmatically using the anchor API, this is the way to go.
To summarise, embed your UIStackView in your UIScrollView, and set the anchor constraints of the UIStackView to match those of the UIScrollView:
stackView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor).isActive = true
stackView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor).isActive = true
stackView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true
stackView.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
stackView.widthAnchor.constraint(equalTo: scrollView.widthAnchor).isActive = true
Just add this to viewdidload:
let insets = UIEdgeInsetsMake(20.0, 0.0, 0.0, 0.0)
scrollVIew.contentInset = insets
scrollVIew.scrollIndicatorInsets = insets
source:
https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/AutolayoutPG/LayoutUsingStackViews.html
You can try ScrollableStackView : https://github.com/gurhub/ScrollableStackView
It's Objective-C and Swift compatible library. It's available through CocoaPods.
Sample Code (Swift)
import ScrollableStackView
var scrollable = ScrollableStackView(frame: view.frame)
view.addSubview(scrollable)
// add your views with
let rectangle = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 55))
rectangle.backgroundColor = UIColor.blue
scrollable.stackView.addArrangedSubview(rectangle)
// ...
Sample Code (Objective-C)
#import ScrollableStackView
ScrollableStackView *scrollable = [[ScrollableStackView alloc] initWithFrame:self.view.frame];
scrollable.stackView.distribution = UIStackViewDistributionFillProportionally;
scrollable.stackView.alignment = UIStackViewAlignmentCenter;
scrollable.stackView.axis = UILayoutConstraintAxisVertical;
[self.view addSubview:scrollable];
UIView *rectangle = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 55)];
[rectangle setBackgroundColor:[UIColor blueColor]];
// add your views with
[scrollable.stackView addArrangedSubview:rectangle];
// ...
Adding some new perspective for macOS Catalyst. Since macOS apps support window resizing, it is possible that your UIStackView will transition from an unscrollable status to a scrollable one, or vice versa. There are two subtle things here:
UIStackView is designed to fit all area it can.
During the transition, UIScrollView will attempt to resize its bounds to account for the newly gained/lost area underneath your navigation bar (or toolbar in the case of macOS apps).
This will unfortunately create an infinite loop. I am not extremely familiar with UIScrollView and its adjustedContentInset, but from my log in its layoutSubviews method, I am seeing the following behavior:
One enlarges the window.
UIScrollView attempts to shrink its bounds (since no need for the area underneath the toolbar).
UIStackView follows.
Somehow UIScrollView is unsatisfied, and decide to restore to the larger bounds. This feels very odd to me since what I am seeing from the log is that UIScrollView.bounds.height == UIStackView.bounds.height.
UIStackView follows.
Then loop to step 2.
It appears to me that two steps would fix the issue:
Align UIStackView.top to UIScrollView.topMargin.
Set contentInsetAdjustmentBehavior to .never.
Here I am concerned with a vertically scrollable view with a vertically growing UIStackView. For a horizontal pair, change the code accordingly.
Hope it helps anyone in the future. Couldn't find anyone mentioning this on the Internet and it costed me quite a long time to figure out what happened.
If any one looking for horizontally scrollview
func createHorizontalStackViewsWithScroll() {
self.view.addSubview(stackScrollView)
stackScrollView.translatesAutoresizingMaskIntoConstraints = false
stackScrollView.heightAnchor.constraint(equalToConstant: 85).isActive = true
stackScrollView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor).isActive = true
stackScrollView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor).isActive = true
stackScrollView.bottomAnchor.constraint(equalTo: visualEffectViews.topAnchor).isActive = true
stackScrollView.addSubview(stackView)
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.topAnchor.constraint(equalTo: stackScrollView.topAnchor).isActive = true
stackView.leadingAnchor.constraint(equalTo: stackScrollView.leadingAnchor).isActive = true
stackView.trailingAnchor.constraint(equalTo: stackScrollView.trailingAnchor).isActive = true
stackView.bottomAnchor.constraint(equalTo: stackScrollView.bottomAnchor).isActive = true
stackView.heightAnchor.constraint(equalTo: stackScrollView.heightAnchor).isActive = true
stackView.distribution = .equalSpacing
stackView.spacing = 5
stackView.axis = .horizontal
stackView.alignment = .fill
for i in 0 ..< images.count {
let photoView = UIButton.init(frame: CGRect(x: 0, y: 0, width: 85, height: 85))
// set button image
photoView.translatesAutoresizingMaskIntoConstraints = false
photoView.heightAnchor.constraint(equalToConstant: photoView.frame.height).isActive = true
photoView.widthAnchor.constraint(equalToConstant: photoView.frame.width).isActive = true
stackView.addArrangedSubview(photoView)
}
stackView.setNeedsLayout()
}
One simple way for dynamic elements in stackview embed in scrollview. In XIB, add a UIStackView inside an UIScrollView and add constraints that the stackview fit the scrollview (top, bottom, lead, trail) and add a constraint to match horizontal center between them. But marked "remove at build time" the last constraint. It make XIB happy and avoid errors.
Example for horizontal scroll:
Then:
Then in your code, just add elements like buttons in your stackview like this:
array.forEach { text in
let button = ShadowButton(frame: .zero)
button.setTitle(text, for: .normal)
myStackView.addArrangedSubview(button)
button.heightAnchor.constraint(equalToConstant: 40).isActive = true
button.widthAnchor.constraint(equalToConstant: 80).isActive = true
}
If you have a constraint to center the Stack View vertically inside the scroll view, just remove it.
Example for a vertical stackview/scrollview (using the EasyPeasy for autolayout):
let scrollView = UIScrollView()
self.view.addSubview(scrollView)
scrollView <- [
Edges(),
Width().like(self.view)
]
let stackView = UIStackView(arrangedSubviews: yourSubviews)
stackView.axis = .vertical
stackView.distribution = .fill
stackView.spacing = 10
scrollView.addSubview(stackView)
stackView <- [
Edges(),
Width().like(self.view)
]
Just make sure that each of your subview's height is defined!
First and foremost design your view, preferably in something like Sketch or get an
idea of what do you want as a scrollable content.
After this make the view controller free form (choose from attribute
inspector) and set height and width as per the intrinsic content
size of your view (to be chosen from the size inspector).
After this in the view controller put a scroll view and this is a
logic, which I have found to be working almost all the times in iOS (it may require going through the documentation of that view class which one can obtain via command + click on that class or via googling)
If you are working with two or more views then first start with a view, which has been introduced earlier or is more primitive and then go to the view which has been introduced
later or is more modern. So here since scroll view has been
introduced first, start with the scroll view first and then go to the
stack view. Here put scroll view constraints to zero in all direction vis-a-vis its super view. Put all your views inside this scroll view and then put them in stack view.
While working with stack view
First start with grounds up(bottoms up approach), ie., if you have labels, text fields and images in your view, then lay out these views first (inside the scroll view) and after that put them in the stack view.
After that tweak the property of stack view. If desired view is still not achieved, then use another stack view.
If still not achieved then play with compression resistance or content hugging priority.
After this add constraints to the stack view.
Also think of using an empty UIView as filler view, if all of the above is not giving satisfactory results.
After making your view, put a constraint between the mother stack view and the scroll view, while constraint children stack view with the mother stack view.
Hopefully by this time it should work fine or you may get a warning from Xcode giving suggestions, read what it says and implement those. Hopefully now you should have a working view as per your expectations:).
For nested or single Stack view scroll view must be set a fixed width with the root view. Main stack view which is inside of scroll view must set the same width. [My scroll view is bellow of a View ignore it]
Set up an equal Width constraint between the UIStackView and
UIScrollView.
Place a scroll view on your scene, and size it so that it fills the scene. Then, place a stack view inside the scroll view, and place the add item button inside the stack view. As soon as everything’s in place, set the following constraints:
Scroll View.Leading = Superview.LeadingMargin
Scroll View.Trailing = Superview.TrailingMargin
Scroll View.Top = Superview.TopMargin
Bottom Layout Guide.Top = Scroll View.Bottom + 20.0
Stack View.Leading = Scroll View.Leading
Stack View.Trailing = Scroll View.Trailing
Stack View.Top = Scroll View.Top
Stack View.Bottom = Scroll View.Bottom
Stack View.Width = Scroll View.Width
code:Stack View.Width = Scroll View.Width is the key.
In my case the number of views inside the stackView was variable and I wanted to center the items. So, for instance, with one view in the stackView, I wanted this view to be centered in the middle of the screen, and if all the views did not fit inside the screen, I wanted the view to be scrollable.
This is the hierarchy of my view.
So I set a fixed width for the button, then, for the stackView:
Same fixed width as the button but with 650 priority.
Align X center to containerView
Trailing >= 0 and leading >= 0 to containerView
Bottom and top space to containerView
For the containerView:
Trailing, leading, bottom, top, equal height, equal width (250 priority) to superview
Fixed height
For the scrollView:
Trailing, leading, bottom, top to superview
The scrollView is also embedded in a view that has leading and trailing constraints.
And about the code I used to approach this:
for index in 0...array.count - 1 {
if index == 0 {
firstButton.setTitle(title, for: .normal)
} else {
let button = UIButton()
button.setTitle(title, for: .normal)
stackView.addArrangedSubview(button)
stackView.setNeedsLayout()
}
}
containerView.layoutIfNeeded()
stackView.distribution = .fillEqually
stackView.spacing = 10
stackView.alignment = .fill
something everyone seems to have missed when doing this with Storyboard is FIX THE MULTIPLIER!
When you're following the steps above in anyones tutorial and resetting the constant to 0 also check the multiplier and reset it to 1, it will have taken on some other factor when visually linking to remain in place
I found I can make a LOOOOOOOOOOOONG text block squash or stretch in a UIStackView simply with
Simply
Add constraints to the scrollview
Top left bottom right, cons 0
Add constraints to the stack view pointing at the scrollbars Content Layout Guide
Then add equal width or equal height constraint from the Frame Layout Guide.
Pick : width if the content needs to scroll vertically, height if it needs to scroll horizontally.
Now here is the key. Edit each constraint and reset the constant to 0 AND set the multiplier back to 1!!!!!
It gets wonky if you don't
If it works you can click on the inner content and mouse scroll
I'm trying to make layout inside scrollview using this one tutorial link
And get the following result link
It will be appreciated for any advices or tutorial links. It needs only vertical scrolling
I am sure there must be other ways to do this but a quick fix is :
1.) Create a width constraint on ContentView in Storyborad.
2.) IBOutlet that widthContraint and set its value to the view frame width in viewDidLoad.
Suppose the name of the constraint outlet is contentViewWidthContraint.
contentViewWidthContraint.constant = self.view.bounds.size.width;
Another alternative to do so from Storyboard, is to fix the Contentview width to the view's width from the storyboard or to the Scrollview, if Scrollview already has a Equal width contraint with superview . Add the "Equal Width" contraint from Contentview to either self.view or to Scrollview (if scrollview, already has the width contraint)
Have you set up the "ContentView" width to match with the scroll view width? I had the same problem and I fixed with "Equal Widths".
"Equal Widths" will tell to your "ContentView" to use the same width of the "Scroll View", which should be fitting the screen if you have set up the constrain properly.
You can do this easily on the storyboard.
Drag and drop, with right click (important!!!), from "ContentView" to "ScrollView"
Release the click, you will be prompted with a menu, select "Equal Widths".
This should fix your problem using the scrollview with AutoLayout from Storyboard editor.
You can find a full tutorial how to use ScrollView with Autolayout and Storyboard here.
I hope this is useful for you :)
In the Storyboard set the width of the elements contained in your UIScrollView equal to the width of this UIScrollView (by selecting all elements and the UIScrollView holding in the panel on the left of your Storyboard and then setting the 'Equal Widths' constraint under 'Pin' on the bottom of your Storyboard). Just pinning the right sides of the elements to that of the UIScrollView won't work as it will adjust the size of its "display view" to the width of the largest element and if this is smaller than the width of the UIScrollView all elements will just appear aligned to its left side.
There is also another possibility that offers a very good result.
You can mark a checkbox:
O programmatically:
scrollView.alwaysBounceVertical = true
Try to set it's width to 0 & height equal to content size like this:
self.scrollView.contentSize = CGSizeMake(0, self.scrollView.contentSize.height);
This will work as you want. Try it & tell if still facing any issue.
For disabling the horizontal scroll, you can set the content size in the -(void)scrollViewDidScroll method.
[self.scrollView setContentOffset: CGPointMake(0, self.scrollView.contentOffset.y)];
self.scrollView.directionalLockEnabled = YES;
This is because scroll view have no idea where your content should end.
But when at least one item inside your scroll view has its "trailing space" constraint attached to a view outside the scroll view (usually a view the scroll view is sitting in or some other view of a higher level, which "knows" its width) - the scroll view will automatically get an idea about your wanted width and won't scroll horizontally (unless that trailing constraint implies having your content outside the screen).
Better if all items inside scroll view have their "trailing space" constraints connected either to each other or to a view outside the scroll view. But not the scroll view itself.
No additional code or extra constraints needed for this to work.
Too set UIScrollView constraints as like below code so it will occupied whole screen.Not exceed the screen size.
Leading Space = 0 from mainView
Top Space = 0 from mainView
Bottom Space = 0 from mainView
Trailing Space = 0 from mainView
You need to set the width of UIScrollView equal to or less than the width of your Parent View. Two ways to do it:
1) You can do this in Storyboard via layout constraints
2) You can do this programatically:
self.scrollView.contentSize = CGSizeMake(self.view.frame.size.width, self.scrollView.contentSize.height);
I have a UIScrollView which contains many UIImageViews, UILabels, etc... the labels are much longer that the UIScrollView, but when I run the app, I cannot click and scroll down...
Why might this be?
Thanks
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.
Make sure you have the contentSize property of the scroll view set to the correct size (ie, one large enough to encompass all your content.)
Uncheck 'Use Autolayout' did the trick for me.
Environment:
xCode 5.0.2
Storyboards
ios7
In my case I had to set delaysContentTouches to true because the objects inside the scrollView were all capturing the touch events and handling themselves rather than letting the scrollView itself handle it.
Set contentSize property of UIScrollview in ViewDidLayoutSubviews method. Something like this
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
scrollView.contentSize = CGSizeMake(view.frame.size.width, view.frame.size.height)
}
if you are getting a message (IOS8 / swift) that viewDidLayoutSubviews does not exist, use the following instead
override func viewDidAppear(animated: Bool)
This fixed it for me
The idea of why scroll view is not scrolling because you set the content size for scrolling less than the size of the scroll view, which is wrong.
You should set the content size bigger than the size of your scroll view to navigate through it while scrolling.
The same idea with zooming, you set the min and max value for zooming which will applied through zooming action.
welcome :)
One small addition, all above are the actual reasons why your scroll view might not be scrolling but sometimes mindlessly this could be the reason specially when scrollview is added through code and not IB, you might have added your subviews to the parent view and not to the scrollview this causes the subview to not scroll
and do keep the content size set and bigger than parent view frame (duhh!!)
I made it working at my first try. With auto layout and everything, no additional code. Then a collection view went banana, crashing at run time, I couldn't find what was wrong, so I deleted and recreated it (I am using Xcode 10 Beta 4. It felt like a bug) and then the scrolling was gone. The Collection view worked again, though!
Many hours later.. this is what fixed it for me. I had the following layout:
UIView
Safe Area
Scroll view
Content view
It's all in the constraints. Safe Area is automatically defined by the system. In the worst case remove all constraints for scroll and content views and do not have IB resetting/creating them for you. Make them manually, it works.
For Scroll view I did: Align Trailing/Top to Safe Area. Equal Width/Height to Safe area.
For Content view I did: Align Trailing/Leading/Top/Bottom to Superview (the scroll view)
basically the concept is to have Content view fitting Scrollview, which is fitting Safe Area.
But as such it didn't work. Content view missed the height. I tried all I could and the only one doing the trick has been a Content view height created control-dragging Content view.. to itself. That defined a fixed height, which value has been computed from the Size of the the view controller (defined as freeform, longer than the real display, to containing all my subviews) and finally it worked again!
Add the UIScrollViewDelegate and adding the following code to the viewDidAppear method fixed it for me.
#interface testScrollViewController () <UIScrollViewDelegate>
-(void)viewDidAppear:(BOOL)animated {
self.scrollView.delegate = self;
self.scrollView.scrollEnabled = YES;
self.scrollView.contentSize = CGSizeMake(375, 800);
}
My issue was resolved by:
setting the contentSize on the scrollView to a large height
BUT also I had to fix top and/or bottom constraints on views within the scrollView, which meant the scroll indicators showed on screen but the content did not scroll
Once I removed top and/or bottom constraints bound to the safe area and/or superview, the views inside the scrollView could scroll again and didn't stay fixed to the top of bottom of the screen!
Hope this stops someone else from hours of pain with this particular issue.
yet another fun case:
scrollview.superview.userInteractionEnabled must be true
I wasted 2+hrs chasing this just to figure out the parent
is UIImageView which, naturally, has userInteractionEnabled == false
Something that wasn't mentioned before!
Make sure your outlet was correctly connected to the scrollView! It should have a filled circle, but even if you have filled circle, scrollView may not been connected - so double check! Hover over the circle and see if the actual scrollview gets highlighted! (This was a case for me)
//Connect below well to the scrollView in the storyBoard
#property (weak, nonatomic) IBOutlet UIScrollView *scrollView;
Alot of the time the code is correct if you have followed a tutorial but what many beginners do not know is that the scrollView is NOT going to scroll normally through the simulator. It is suppose to scroll only when you press down on the mousepad and simultaneously scroll. Many Experienced XCode/Swift/Obj-C users are so use to doing this and so they do not know how it could possibly be overlooked by beginners. Ciao :-)
#IBOutlet weak var scrollView: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(scrollView)
// Do any additional setup after the view
}
override func viewWillLayoutSubviews(){
super.viewWillLayoutSubviews()
scrollView.contentSize = CGSize(width: 375, height: 800)
}
This code will work perfectly fine as long as you do what I said up above
If none of the other solutions work for you, double check that your scroll view actually is a UIScrollView in Interface Builder.
At some point in the last few days, my UIScrollView spontaneously changed type to a UIView, even though its class said UIScrollView in the inspector. I'm using Xcode 5.1 (5B130a).
You can either create a new scroll view and copy the measurements, settings and constraints from the old view, or you can manually change your view to a UIScrollView in the xib file. I did a compare and found the following differences:
Original:
<scrollView clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="scaleToFill" directionalLockEnabled="YES" bounces="NO" pagingEnabled="YES" showsHorizontalScrollIndicator="NO" showsVerticalScrollIndicator="NO" translatesAutoresizingMaskIntoConstraints="NO" id="Wsk-WB-LMH">
...
</scrollView>
After type spontaneously changed:
<view clearsContextBeforeDrawing="NO" contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" customClass="UIScrollView" id="qRn-TP-cXd">
...
</view>
So I replaced the <view> line with my original <scrollView> line.
I also replaced the view's close tag </view> with </scrollView>.
Be sure to keep the id the same as the current view, in this case: id="qRn-TP-cXd".
I also had to flush the xib from Xcode's cache by deleting the app's derived data:
Xcode->Window->Organizer->Projects, choose your project, on the Derived Data line, click Delete...
Or if using a device:
Xcode->Window->Organizer->Device, choose your device->Applications, choose your app, click (-)
Now clean the project, and remove the app from the simulator/device:
Xcode->Product->Clean
iOS Simulator/device->press and hold the app->click the (X) to remove it
You should then be able to build and run your app and have scrolling functionality again.
P.S. I didn't have to set the scroll view's content size in viewDidLayoutSubviews or turn off auto layout, but YMMV.
If your scrollView is a subview of a containerView of some type, then make sure that your scrollView is within the frame or bounds of the containerView. I had containerView.clipsToBounds = NO which still allowed me see the scrollView, but because scrollView wasn't within the bounds of containerView it wouldn't detect touch events.
For example:
containerView.frame = CGRectMake(0, 0, 200, 200);
scrollView.frame = CGRectMake(0, 200, 200, 200);
[containerView addSubview:scrollView];
scrollView.userInteractionEnabled = YES;
You will be able to see the scrollView but it won't receive user interactions.
adding the following code in viewDidLayoutSubviews worked for me with Autolayout. After trying all the answers:
- (void)viewDidLayoutSubviews
{
self.activationScrollView.contentSize = CGSizeMake(IPHONE_SCREEN_WIDTH, 620);
}
//set the height of content size as required
The straightforward programmatically way
To wrap it up
Create a UIScrollView
private lazy var scrollView: UIScrollView = {
let scrollView = UIScrollView()
scrollView.translatesAutoresizingMaskIntoConstraints = false
return scrollView
}()
Use a Single Child View to Hold All of Your Content Subviews
private lazy var contentView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
Add your views
contentView.addSubview(firstSubView)
contentView.addSubview(lastSubView)
scrollView.addSubview(contentView)
view.addSubview(scrollView)
Usually, you only want your content to scroll in one direction. In most cases to scroll vertically. Therefore set the width of the content view to be the width of the scroll view.
NSLayoutConstraint.activate([
contentView.widthAnchor.constraint(equalTo: scrollView.widthAnchor)
Attach four constraints (top, bottom, left, right) from our single content view to the scroll view.
contentView.topAnchor.constraint(equalTo: scrollView.topAnchor),
contentView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor),
contentView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor),
contentView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor),
Make sure you have constraints attached to all four sides of the content view so that it will expand to the size of your content.
// After Adding your subviews to the contentView make sure you've those two constraints set:
firstSubView.topAnchor.constraint(equalTo: contentView.topAnchor),
.
.
.
lastSubView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor),
])
Reference: Using UIScrollView with Auto Layout in iOS
After failing with the provided answers in this thread, I stumbled upon this article with the solution.
There are two things not intuitive about setting up the scrollview with autolayout:
The constraints you set up as margin between the contentview and scrollview do not influence the size of the contentview. They really are margins. And to make it work, the contentview should have a fixed size.
The trick to the fixed size is that you can set the width of the contentview equal to that of the scrollview's parent. Just select both views in the tree on the left and add the equal widths constraint.
This is the gist of that article. For a complete explanation, including illustrations, check it out.
I found that with this AutoLayout issue... if I just make the ViewController use UIView instead of UIScrollView for the class... then just add a UIScrollView myself... that it works.
I had the same issue in IB.
After setting the leading, trailing, top and bottom of the scrollView to its superView. I made the following changes to make the containerView scrollable, which worked.
To make the scrollView only scroll on horizontal direction make the constraint with scrollView's centerY = ContainerView's centerY
and to make it vertically scrollable make the scrollView's centerX = ContainerView's centerX
You don’t have to set the content size of the scroll view.
Technical Note TN2154
In case someone made the same mistake like me, I'd like to share my case.
In my case, I mistakenly add a constraint to one of the subviews of scrollview which makes the subview's space to the topLayoutGuide fixed, thus it's location can't be changed, so the scrollview can't be scrolled.