I have a UIScrollView which is set up with AutoLayout. I have a constraint on the "Save" button from the bottom of the button to the bottom of the scrollview, set to 0. The scrollview also has a bottom constraint of zero to the superview. Meaning, that the Save button SHOULD be 0 pixels away from the bottom, and even says so on the attributes inspector (see screenshot). How come, when I run the project, or even view from the storyboard, that this button is NOT at the bottom of the screen? Why is the save button refusing to align on the bottom of the scrollview and thus the bottom of the screen?
According to this article: https://www.natashatherobot.com/ios-autolayout-scrollview/ , the best way to deal with scrollview is to make sure only one view (we will call this contentView) is within the scrollview. Place all the subviews within contentView, and the trick is to use equal height and width from the scrollview to that contentView. I was able to solve my issue that way.
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I am using autolayout in Xcode and am creating a fairly tall (1300px) ViewController with a uiscrollview to navigate up and down. I made the viewcontroller freeform so its dimensions are [375,1300]. I then incorporated the scrollview, added the content view as well as all the subviews & constrained everything, leaving no constraint errors. At runtime there are no errors, but everything is all smushed into the normal screen size when I intended for it to be very tall (~1300px) and scrollable. Any clue as to what I am doing wrong?
Below is a diagram showing the issue where:
The Outer Black Blox is the ViewController's view
The Inner Black Boxes are subviews
and The Blue Box is what is displayed on the screen
Yes, your correct #Ryan Cocuzzo. I think you need to set sub view priority from 1000 to 250. See below screen shots.
1) Select height constraint of the subview
2)Then go to show to size inspector
3) Now change the priority constraint from 1000 to 250.
4)Finally you get like this
Make sure the following are true:
The 4 content views are subviews of the UIScrollView, not your view controller.
The autolayout constraints on the 4 content views must reference the UIScrollView only, not the view controller's view.
The 4th box cannot have a bottom constraint.
It looks like the 4th box has a constraint to make it's bottom align with the bottom of the view controller's view. This would force the other views to smush up together. The 4th box also cannot have a bottom constraint so that the scrollview can resize itself to encompass it's subviews.
I have a label, an Image View, and a button in a vertical stack view. The alignment is set to fill, and the distribution to equal spacing with an offset of 10. On my storyboard, the label appears on top, the image in center, and the button at bottom.
However, when run on simulator or device, the UIView is stripped from the view entirely, so the label appears at the top of the screen, and the button directly below the label.
My only constraints are set on the stack views to the superview
Edit: Forgot to mention the UIImageView is inside of a UIView
I had a similar problem. My UIView in my UIStackView had only a Width constraint and would disappear at runtime. I found I could make it show up again with either of these options:
Add a Height constraint
Add a Top and Bottom constraint
I was having the same issue with a tableview in a stackview. Added the Height constraint to the view and it worked now everything shows fine
Setting a Y constraint on the UIView border caused it to appear when hitting the play button, but it grew outside of the screen bounds.
I had to set size constraints on the UIView in order for it to display properly.
I have a weird behavior when I use scrollView.
As you can see in the picture bellow the button called "Back" has a bottom space constraint with value 0. But we can see is not even near to the bottom of the scroll view.
I already set the scrollview to have equals width and height of the superView and top,bottom,trailing and leading space with 0 value.
How can I fix this? I want the Back button still inside of the scrollview and put it at the bottom of the view.
Update
I have the code here https://github.com/rchampa/NDParallaxIntroView and the xib is called PageB.xib
Ricardo: you've added two constraint regarding manage y position of Validate Code button where your top constraint stop to move Validate Code button towards the bottom. So please remove top constraint of Validate Code only add bottom constraint.
you need to manage all constraint like your scrollview content view height will be equal to height. Please increase some top constraint from top.
So, if I understand correctly, the problem you are running into is that your back button is unable to be positioned based on the bottom of the scroll view.
A scroll has two sets of constraints in a storyboard, one that defines the size of the scroll view, and the other that defines the content size. The top, left, bottom, right to superview constraints on the scroll view will define the size.
The part that is causing your problem is that the content size is defined by the subviews inside the scroll view. So the button cannot be placed relative to the bottom of the scroll view since the scroll view doesn't know how large its content size is. All of the subviews of a scroll view must be placed in relation to each other.
So, create constraints for your logo, text fields, and all the buttons in relation to each other. Then create constraints from the outer most subviews to the scroll view.
In your example, you would constraints from the logo to the text field, 1st text field to 2nd text field, then 2nd text flied to the label, label to the "Send email..." button, and finally "Send email..." to the "Validate Code". For the "Back" button, it would need a left align with the text fields and then a center align with the "Validate Code" button. Create a top constraint from the logo to the scroll view. Then have leading and trailing constraints from one of the text fields to the scroll view. Finally, create a bottom constraint from either the "Back" or "Validate Code" buttons to the scroll view. You will also need some alignment constraints (logo center to the text field is an example of one). After that is all setup, your view will be fully defined for the content size of the scroll view.
If I understand you, my new question is: how can I make the subviews
make the height of scroll fit 100% screen device height? Is there a
way to define weights like Android? I don't know how achieve this
since the canvas is 600*600 which is different to every device.
Response would be too long for a comment:
So you wouldn't use a scroll view for that. A scroll view is specifically for containing content that will not fit on the screen (so the user can scroll to reach the new content).
The simplest solution is to add a regular view that has TopLeftBottomRight 0 distance constraints (so it is the max height and width of the screen) and setup the view like you have here to position the bottom in the bottom left all the time.
There is also a weight system, I can explain that if you want, but it wouldn't be required thus far.
I feel like your next response will be something like "what if I want it to scroll when its too small for the current screen?". The only way I know of doing that in encapsulating all your interface into a single UIView, and changing its sized in the viewDidLoad/viewDidAppear based on the size of the scroll view. Something like this:
func viewDidLoad() {
super.viewDidLoad()
containerViewHeightConstraint.constant = scrollView.frame.size.height
containerViewWidthConstraint.constant = scrollView.frame.size.width
}
I making a article detail view like Facebook.
This view have content(profile image, writer, date, content text) and comment write view.
So Top view is UIScrollview, Bottom view is UIView.
UIScrollView have UIImageview, UILabel*3,
UIView have UITextView, UIButton.
When touch UITextView in UIView, the keyboard comes up.
So UIScrollview will be smaller and UIView position will be moved.
And User will write text, UITextView line will be added so UIView Size will be extended.
Eventually UIScrollview and UIView height not Determinate.
How to set autolayout this view?
Instead of having UIView for textView and button, what i would suggest you is, just add one scrollView set its constraints as below
Then add a UIView as container view inside scroll view, (select scroll view go to Editor, select Embed In, and select View) and set its constraint as below
Now add your imageView, labels, textView and button one by one, and make sure your set imageView's top space to view and button's (which is at the bottom of screen) bottom space to view, and all other view's top space and bottom space to their nearest views, this way scroll view can easily determine the height required for it.
One last thing, when user click inside textView you might need to move scrollView upward in order to make textView visible to user while he is typing, to do this one easy solution is just download the library 'TPKeyboardAvoiding' from here add all classes to your project and once done, set your scrollView's custom class to 'TPKeyboardAvoidingScrollView'. Clean and run the project, it should work..
May try it:
What I say below is about constraint:
UIScrollView top, left, right equal self.view top, left, right
UIScrollView bottom equal UIView bottom
UIView left, right, bottom equal self.view left, right, bottom UIView height equal 200(you set it)
OK, when you UITextView is touched, set the UIView height constraint to what you want(maybe 300)
I think it works!
My problem is slightly different from other's 'Swift UIScrollView' problems when using auto layout:
Problem:
Unlike others, when I run my app, it scrolls. My problem is that the scroll cuts off the bottom 20-30% of the content. I can pull to see the buttons did build and are down there, but when I let it go the scroll snaps back to a false bottom which cuts off my content!!! I've been trying, for days, to fix it to scroll the entire height but it continues to cut off!!
Description of app:
I used auto layout to layout 6 buttons and labels. Each button a rectangular image, with a label directly beneath it. (sorry, the site won't let me post pictures!)
I have my views arranged like this:
MainView > ScrollView > ContentView > Buttons & Labels
I have my contentView pinned to my ScrollView and my ScrollView pinned to my MainView. My buttons and labels all have constraints that are building correctly, to create a list that looks like:
Rectangular button
Label beneath it
Spacing
Rectangular button
Label beneath it
Spacing
Etc.
Can anyone tell me why I can't scroll the full length of the view?
Your description of how your items are constrained is vague, so I'm going to list all of the constraints you need to make this work. Then you can compare what you have to what you need and adjust accordingly.
Your ScrollView should be pinned on all 4 sides to the MainView. (This isn't absolutely necessary. You can constrain your ScrollView however you want, but make sure it can grow as the device and/or orientation changes).
Your ContentView should be pinned on all 4 sides to the ScrollView with offsets of 0.
Since you want your ScrollView to scroll vertically only, constrain the width of the ContentView to the width of the ScrollView using an Equal Widths constraint. To do this, in the Document Outline view, Control-drag from your ContentView to your ScrollView and select Equal Widths from the pop up.
The height of ContentView will be set by the sum total height of everything in it. In order for this to work, your topmost button needs to be pinned to the top of the ContentView, all of your buttons and labels should be pinned to their nearest neighbors, and the bottommost label should be pinned to the bottom of the ContentView. In addition, all of your buttons and labels should have constraints for their widths and heights. I would suggest setting an explicit width constraint and explicit height constraint for your buttons and centering them horizontally in the ContentView. For your labels, set an explicit height constraint and pin the left and right edges to the ContentView.
If you have these constraints and no other ones, your ContentView will be properly sized.
Using contentView, like you said, usually fixes the issue. So chances are you need to take a second look at your contraints. Maybe try this solution in a clean/new project to see that it works. (it does work). My guess would be that some of your constraints conflict each other.
Otherwise I think it would be a good idea to setContentSize of your scrollView in your viewDidLoad.
Another hack would be to place 2 UI objects with their alphas set to zero on the right top corner and left bottom corner. This would hint scrollView to set its contentSize.