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
I'm having trouble getting this working, best explained what i am trying to do with this image of my storyboard.
The main goal is to make that container scrollable, with its size dependent on the view controller that gets added into it via code.
Here is how i have laid out my views.
Obviously my constraints are what is messing me up, but not exactly sure how to get them to behave as expected, I've tried pinning the container to the scroll view and then the scroll view to the main view. The screen appears how i want but it just doesn't scroll.
Any help is much appreciated!
It's impossible from your question & screenshots to determine what constraints you actually do have set up. And your question doesn't even particularly make it clear whether your constraints are behaving properly (aside from the scroll view not scrolling, which may or may not be related to constraints).
First, we need to make sure our constraints are hooked up correctly. The container view for which you're going to put a scroll view into should have four constraints. One for each side, left & right, pinning it to those edges. One for the bottom to pin it to the toolbar, and one for the top to pin it to your top views. It doesn't need any more constraints. Now, the toolbar at the bottom and your views at the top need to have their constraints set up so that they have a constant height per device/orientation, and does not care about the size of the container view. If your constraints are set up correctly, then resizing this view in your interface builder file should be changing the size of the container view. If this isn't happening, head back to the drawing board because something isn't quite right.
If you are confident your constraints are set up correctly, there are a few other things about the scrollview itself that could prevent scrolling.
First, check the most obvious. Is the scrolling enabled property set to true on your scroll view? If not... of course it's not going to scroll.
The other thing that could be happening is that your content view is not larger than the scroll view. Make sure that you've properly set up autolayout for the contents of the scroll view, otherwise the content view will not be larger than the scroll view, and no scrolling will be happening.
So for anyone wondering how to do this, i finally figured out how to do it after a lot of trial and error.
Basically what I did was remove the container view from the storyboard, set my constraints on the scroll view as i normally would:
and then added a container view as a subview of the scroll view in code:
var containerView : UIView!
var currentViewController: UIViewController
override func viewDidLoad() {
super.viewDidLoad()
self.containerView = UIView()
self.scrollView.addSubview(self.containerView)
}
To swap between different view controllers using my UISegmentControl and have the scroll view scroll the content no matter how large the new view controller is i added the following code in my UISegmentControl functions
#IBAction func segControlValueChanged(sender: AnyObject) {
if let vc = viewControllerForSelectedSegmentIndex(sender.selectedSegmentIndex) {
self.currentViewController!.view.removeFromSuperview()
self.currentViewController!.removeFromParentViewController()
displayCurrentTab(sender.selectedSegmentIndex)
}
}
func displayCurrentTab(tabIndex: Int){
if let vc = viewControllerForSelectedSegmentIndex(tabIndex) {
self.addChildViewController(vc)
self.containerView.addSubview(vc.view)
vc.didMoveToParentViewController(self)
vc.view.frame.size = CGSize(width: self.view.frame.width, height: vc.view.frame.height) //had to add this because otherwise for some reason my new vc width would not increase or decrease to its parent view
self.currentViewController = vc
self.scrollView.contentSize = vc.view.frame.size
}
}
func viewControllerForSelectedSegmentIndex(index: Int) -> UIViewController {
//instantiate and return your view controller here
}
Some other notes:
I disabled "resize view from NIB" in storyboard for all my view controllers i plan to add to the container
I need to display the layout I have in the picture in my app.
The view hierarchy is:
scroll view (scrollEnabled = true)
image view
label
webview (scrollEnabled = false)
table view (scrollEnabled = false, max amount of rows = 6)
The web view height is dynamically changed by it's delegate webViewDidFinishLoad.
func webViewDidFinishLoad(webView: UIWebView) {
webView.sizeToFit()
}
How can I set up the auto layout to move the table view below the web view?
First of all you need to add containerView in scrollView and then add subViews to containerView.
Below I’ve displayed the hierarchy you need to follow for displaying content in UIScrollView and the constraints you need to set.
scroll View (constraints :- leading,trailing,top,bottom)
Container View (constraints :- leading,trailing,top,bottom,widthsEqually to View,heightsEqually to View or height = 1000)
NOTE : If all subViews has specific height then there is no need to give height to ContainerView.
UIImageView (constraints :- leading,trailing,top,verticalSpacing,height)
UILabel (constraints :- leading,trailing,top,verticalSpacing,height)
UIWebView (constraints :- leading,trailing,top,verticalSpacing,height>=0)
UITableView (constraints :- leading,trailing,top,Bottom)
NOTE: give height to tableView if required. You will need to make changes in height constraint of UIWebView programmatically at run time based on your requirement.
For more reference please refer links below:
http://spin.atomicobject.com/2014/03/05/uiscrollview-autolayout-ios/
http://blog.surecase.eu/working-with-uiscrollview-in-storyboard-using-autolayout/
http://makeapppie.com/2014/12/11/swift-swift-using-uiscrollview-with-autolayout/
I have a view that is larger than screen, I need to put it in a UIScrollView.
So I first add an UIViewController to story board, then, I add a UIScrollView to the root view of my view controller, then when I add subviews of UIScrollView, but I can't add them outside the scrollview area I can see, how to solve this problem?
Change the simulated size of the view controller to Freeform and then you can set the size to whatever you want. After editing, you may want to set it back.
Edit 1:
1) put your subview into scrollview's visible area
2) change frame of the new subview as you wish
3) change contentSize property of scrollview with runtime attributes
Edit 2:
u can create a new view with xib, which contains all your subviews, and then add this view on scrollview OR u can use storyboard's Container View like this:
p.s.: don't forget about contentSize (point 3 in my first edit), but if you are using auto-layout, you need to set it programmatically like this:
- (void)viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
_scrollView.contentSize = CGSizeMake(320, 250);
}
put a scroll view in the view controller ,and put a view inside the scroll view named containerView.
design the big content in another view controller (named bigContentView)
in code ,view load event ,
a. get the bigContentView by storyboard Id. ( get the controller and use controller.view)
b. create the outlet to the containerView.
c. update the containerView's frame according your requirement.(update the width and height)
d. bigContentView.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth;
e. containerView addSubView:bigContentView.
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.