I have a UIScrollView created in interface builder with a bunch of UITextView and UIImageView objects already added. I have it connected to an IBOutlet, and under -(void)viewDidLoad I set its content size to 1200x2000. User interaction Enabled, Multitouch, Scrolling Enabled and shows vertical and horizontal scroll indicators are all set to YES. When I launch the app in the iOS simulator, it doesn't scroll. What could possibly be the cause of this behavior?
viewDidLoad is to soon. You must wait until after the layout of the views has taken place. Try setting the contentSize in viewDidAppear.
Are you using autolayout? If so, check out the following answer (and forget 1.):
UIScrollView doesn't use autolayout constraints.
The best way I know how to overcome this problem without resorting to writing code is that it all can be done within a storyboard and here is how:
Leave autolayout enabled.
Make a generic UIView a subview of the UIScrollView. 2.1)Put all your View components inside this generic UIView.
Make a autolayout constraint between a subview and the UIScrollView. You must pin the right and/or bottom of the last subview to the right and/or bottom of the UIScrollView. This is how the UIScrollView knows the content size.
viewDidLoad is indeed too soon, but viewDidAppear:animated might not be late enough either. The ideal place to set the contentOffset is inside viewDidLayoutSubviews.
If you're using Autolayout, make sure you put the code to set Content size within
viewDidLayoutSubviews
I use a custom view on the UIScrollView, for pull to refresh function, and the scroll view is not scrollable. I try set contentSize with AutoLayout, and try set it by codes too. The scroll view still cannot scroll.
After spending 3 ~ 4 hours, I solve it by contentInset. It will tell scroll view to add some extra space for scrolling.
override func viewDidLayoutSubviews() {
// Add extra 15pt on the `top` of scrollView.
//self.scrollView.contentInset = UIEdgeInsetsMake(15, 0, 0, 0)
// Add extra 2pt on the `bottom` of scrollView, let it be scrollable. And the UI is more beautiful in my case.
self.scrollView.contentInset = UIEdgeInsetsMake(0, 0, 2, 0)
}
Reference docs:
Understanding the contentOffset and contentInset properties of the UIScrollView class #blog
What's the UIScrollView contentInset property for? #Stackoverflow
This is a good walk-through of scroll-views in case anyone forgot after not using them for a while: https://medium.com/#pradeep_chauhan/how-to-configure-a-uiscrollview-with-auto-layout-in-interface-builder-218dcb4022d7.
Basically, make sure you have view -> scrollview -> view, like so:
then,
1. Set scroll view constraint (top, bottom, leading and trailing) to (0,0,0,0).
2. Set inner view constraint (top, bottom, leading and trailing) to (0,0,0,0).
3. Set inner view to have equal width and equal height with parent view.
4. Select height constraint of inner view and set priority to low (250).
Related
Ok, so what I have is a UIScrollView that is constrained to all four sides of the main view, centered both vertically and horizontally, and set to have equal width and height to the view. All of the subviews that I put on top of the UIScrollView are showing up when I run the app, exactly where I want them to be, but only the UITextView at the bottom is not. It seems like I've tried every combination of constraints but it never appears when I run the app regardless of what I do. Here is a screenshot of the constraints in the interface builder:
And even when I preview the file Main.storyboard before running it looks like this:
But when I actually run the app, the screen is missing the UITextView, even when I alter the constraints in a number of ways:
Any help with this problem will be greatly appreciated! Thanks in advance.
Avoid putting all your subviews directly inside the scrollView. The autolayout will break apart.
You need to :
Add a UIView inside the UIScrollView, with constraints 0-0-0-0 to leading-top-bottom-trailing to the UIScrollView, and put all your subViews inside that UIView.
After that, you need to set the contentSize of your UIScrollView by code.
Also, you can:
add missing constraints to see what is missing.
The left panel in UIStoryBoard (Document Outline), you can press the red arrow showing up to see what is missing or conflicting.
Check out Apple documentation for more details.
If you want your scrollView only scrolls vertically you shouldn't set its height equal to its superView so remove it and just set the width to its superView and then it should calculate the height based on the subViews inside it
I offer you to drag a UIView in your scrollView and set the constraints to its four sides, and name it containerView , then set its width equal to background view and start laying out your views inside it not inside the scrollview :)
If Height of all views in the scrollView is clear, it can infer the scrollView's height
in this case you can set a fixed height to your containerView like 800 to get rid of the red lines and check how it works :)
I have noticed some clues you might have to solve which could probably solve the issue. Since the scrollView is extend by its content's elements, you have to explicitly deal with each element in the scrollView:
For imageView on the top is not well constrained, you need to give it a width or aspect ratio. Fix the imageView issue might solve textview height problem, even it's not still is a good start.
TextView bottom anchor is equal to scrollView bottom anchor, but you have to know textView is also kind of scrollView. So it's not reasonable to constraint each other at same time. Because both of them don't have explicitly height. You can try to type some words in the textView which will at least give it height by its content, then the scrollView can detect the textView bottomAnchor. You might see something then.
Your scrollView's height is equal to view's height is also weird, scrollView shouldn't constraint its height at first. Because it can't be "Scroll"View anymore because it's height is constant. you should let its width equal to view, and let the height be decided by its element's height. Then it will be literally a scrollview.
Hope it helps
I am adding more than 8-9 controls in my ScrollView but I am not able to set ContaintSize of that ScrollView so that I can able to scroll and view all controlls.
I HAVE SET below constrains to my scrollview and add some controls into my scroll view with the help of contain view.
Scrollview.top respect to his superview
Scrollview.bottom respect to his superview
Scrollview.leading respect to his superview
Scrollview.trailling reapect to his superview
Than I have added UIView as contain view and set all constrain respect to scrollview.
Than added all controls into view but still its not scrolling as expected.
By below code I am able to set containview but its ststic one and cant assume that 1000 is my contanent height.
Scrollview.contentsize = CGSizeMake (Scrollview.frame.size.width,1000);
Above part is static as I have many lable with multiple line in it.
All data is dynamic comes from server si cant set it static.
Can any one help me out how to set autolayout of scrollview so I can get dynamic content size?
Edit: some time I am getting autolayout error into storyboard like below.
Scrollview has ambiguous scrollable content height
An while i reslove conflicts its not showing proper scrollview in my screen.
Faced the same issue recently. I'm sure that you did your research but here is the guide I used, nonetheless.
https://www.natashatherobot.com/ios-autolayout-scrollview/
Also if you have many labels it would be good consider using a 'UITableView' or a 'UIStackView'.
Edit
Make sure you center the scroll view vertically and horizontally in respect to its container.
You have to define constraints for the scroll view like this..
ScrollView :
top ,left , bottom, right pinned to superview.
ContainerView:
top, left , bottom , right pinned to scroll view
width pinned to main view
And make sure that every subview inside the container view should have constraints in such a way that it should define the height of container view.
As i understand your issue you forgot to set the height constraint of your contentView, just try by setting it.
No need to set the fix height of scrollView's contentSize, please see the below code.
self.scrollview.contentSize = CGSizeMake(self.contentView.frame.size.width, contentView.frame.origin.y + contentView.frame.size.height + 10);
Note: you need to add height and width constraint of contentView if you need scroll according to it.
I have a followed this answer Putting a UIScrollview in a viewcontroller (storyboard) to embed a scrollview in a viewcontroller (Mine is vertically instead of horizontally).
All the constrains are working except the fact that the view bounces back when it is let go. I have tried a lot of different solution, but none is working! Please help, I'm using autolayouts my main goal is to be able to show all the buttons on the screen through scrolling.
EDIT:
I have been trying all types of ways to increase the contentSize, but nothing happens - the scrollview won't scroll properly. I tried different codes from people with the same problem, but the bouncing won't stop. Am I doing anything wrong on my constraints? This is extremely frustrating, please help. My constraints (using autolayout) (as I said, I followed this answer Putting a UIScrollview in a viewcontroller (storyboard))
You have to increase your scrollView's contentSize to fit all of it's sub views.
You should add subview to scrollview, then add all other views to that subview.
scrollView
contentView
subview_1
subview_2
Then add constraints between scrollView and contentView (leading, trailing, top, bottom) and contentView should have width and height constraints set properly (set width equal to scrollView width)... the content size will be calculated automatically.... just set height
I have a real problem with detecting UIScrollView height. I searched a lot and found this solution:
So I dragged from Content View to View and made Equal Height. But I does not work for me.
I also tried to calculate scrollView height according to elements height in it, but I do not think that it's a right way.
How can I set UIScrollView height dynamically? What is the correct way for doing it?
Your ScrollView should add a ContentView like this:
select your scrollView and in size Inspector bottom, set the width like this:
for more details on how to handle scrollView in Interface Builder your can check out this AppleDoc Working with Scroll Views
Hope this help you!
You only way to set height of your scrollView is by calculating the height of individual objects added to scrollview.
Programatically, calculate the height of each UI object and at the end set content height to scrollview.
[scView setContentSize:CGSizeMake(300, height)];
In above line, 'height' is nothing but a sum of all heights of all UI objects calculated.
By doing the below stuff's, I was able to implement UIScrollView with Automatic height based on the contents inside.
Add scrollview to the main view.
Add one ContentView inside this container scroll view.
Give proper constraints inside this content
view to the container scroll view as well as to its internal UI
Components. Please note that you should not give fixed height to the
content View. The constraints of the content view should grow
according to the UI Components inside
This might give you a layout
warning as 'Unambigous.... '. To fix this, give 'Equal Heights' constraint relation between content view and scroll view
Try the above steps, and this will solve your issue :)
Do you want to add item (UIView, UILabel...) in your UIScrollView by auto layout? If so, just put these in it and create correct constraints for them.
The key point is each item which in UIScrollView have top, leading, bottom and trailing side constraints to their superview. Most important is Make Sure that your UIScrollView has top, leading, bottom and trailing Descendant Constraints to its sub-items. It will calculate correct content height of scroll view for you.
In your solution, if your contentView has zero frame, it will not give you any height for scroll view.
I can't understand how can I solve this auto layout problem, i have this View:
There is an UIScrollView with the elements you see in the View, but the View gives me this warning:
scrollview has ambiguous content width
I can't understand how to solve this problem, I want the the view is for the full screen size, and I want that the width will be the screen width, how I can solve it?
I observed its fix in XCode 7.3 and it is just 10 sec work. I made a video on it. Check here:
https://www.youtube.com/watch?v=yETZKqdaPiI
All you have to do, add a subview to UIScrollView with same width and height. Then select ViewController and press Reset to suggested constraint. Please check video for clear understanding.
Thanks
This is because you are not providing enough constraints so that Xcode can find Width of your scroll view.
You can see on your screen there isn't any constraints that can be satisfied to find width of scroll view.
You can do it by providing leading and trailing space of Image view which contains fix width. It also can be done with any other views. But i will prefer control which contains fix Height & Width So there isn't require to set hugging priority or Compress resistance.
Put everything in a View and that View put inside a ScrollView.
Editor -> Embed in -> View
The solutions is:
You have a UIImageView at the top. You set the width of the UIImageView to be the same as the width of the root view of the UIViewController
You set the leading and trailing space of the UIImageView to the UIScrollView to be both 0
You set the height of the UIImageView to be the height you want the image to be. And then you set the view mode of the UIImageView to be 'Aspect fit'.
I had the same problem a month ago. Add a constraint that makes the UIView inside the UIScrollView have the same size of the UIScrollView's content width. If you have multiple views inside the UIScrollView, put your UIViews inside a new UIView and make sure the new UIView has the same content width size as the UIScrollView.
Best regards,
I too faced this issue and the only way i got it solved was using the below strategy
Add a scroll view and set its constraint to fill in the screen
Add a UIview inside the scroll view lets call this view as the content view.
In this contentView, set top, bottom, left and right margins to 0 (of course from the scrollView which is the superView);
This should do it now you can follow step 3 and continue with your UI
Place your view inside the content view and add constraints to it accordingly.
Hope it helps