UIScrollView has an unexplainable position in UITabBarController with autolayout - ios

Using Xcode to create a new project, a Tabbed Application.
On the first view controller I add a UIScrollView, bind it to the view for all borders. Then I add a UIView "Content View" with equal width as the superview of the UIScrollView. I add a label on the top and a label on the bottom of the content view, and make sure that the size of the content view amounts to a higher height than the height of the scroll view, so that we get a scroll.
Still I get a horizontal scroll bar in the view. Why? The width of the content view is bound to the width of the superview of the scroll view, which should thus be as wide as the device, and give no scroll. What am I missing?
The project is downloadable from here if you want to play with it.

Your problem is that you have two constraints for the ScrollView which are set relative to the margin.
If you make the leading and trailing constraints relative to the superview with no margin then your code works as you require with no horizontal scroll bar.

Related

Scrollview in storyboard does not scroll

I created a scrollview in storyboard with multiple views but the scrollview does not scroll. See the screenshot. I have a scrollview with images and another view embedded that spans outside the view area. I would like the scroll view to scroll down but it does not when I see the code in the simulator.
You need to add a UIView with 1000(or whatever you want) height constant to scrollView and make the UIView equal width to view
ScrollView needs to know its scrollable area, so you need to provide information about width and height for ScrollView's content:
width - you can create empty view (with height constraint equal to 1), place it inside scrollView, set its leading and trailing constraints to scrollView and set width constraint equal to main view. Then, scrollView will know that its scrollable area has the same width as screen.
height - you need to provide top and bottom constraints for first and last components inside scrollView (and all components should have specified height). I guess you forgot about setting bottom constraint for the last item.

iOS - A view controller uiview having horizontal and vertical scrolling

I am looking for some guidance on creating a view controller with uiview and scroll view that allows horizontal as well as vertical scrolling. My uiview needs to be wider and taller than the width of the iPhone so that it holds more content in both directions.
I tried by modifying the view controller property to freeform and increasing its width and height. This does allow scrolling to happen vertical and hold more content but cannot achieve the same in horizontal direction.
I want to create a map of a building that someone could scroll in both directions to view it completely.
Is it possible, if so how?
Thanks.
It depends on the Content size of ScrollView, not on the size of ViewController in the Interface builder (Storyboard).
Try to add a view inside Scrollview and add Top, Bottom, Leading, Trailing constraints with that view to Superview. Along with that add width and height constraints to the view (that's added in the scroll view) and make sure that width and height constraint value is greater than the size of Window (iPhone screen).
For detail refer this link https://developer.apple.com/library/archive/documentation/WindowsViews/Conceptual/UIScrollView_pg/CreatingBasicScrollViews/CreatingBasicScrollViews.html#//apple_ref/doc/uid/TP40008179-CH101-SW2

UIScrollView with Content View

I've been trying to create a UIScrollView for user registry but with no success. I'm using auto layout and all of the fields that go inside the scroll view are static. Because of the usual ambiguous height issue, I've added a UIView inside the scroll view, set the constraints to the margins of the scroll view and centered aligned it. After that I added all of the fields inside that Content View, in the storyboard.
The content fields have their constraints setup as you would expect, but when I get to the lowest field and set the bottom constraint to the bottom of the Content View then everything breaks.
I'm asked by Xcode to set the priority of some views, and when I do as is says, the Content View size stays the same and the views are shrunken.
I tried not to put the last bottom constraint and resize the Content View by code but the height is not resized as is should.
I'm looking for a good solution to do this in storyboards and auto layout.
Update: I added a bottom constraint with a low priority, but the content scroll view is not expanding to show all of the fields.
Add&Set ScrollView(UIScrollView)
Add&Set ContentView(UIView) with subviews
! Set ContentView Width equal to View Width
Set all subviews constraints
View1 should be tied to the top of the ContentView
View4 should be tied to the bottom of the ContentView
All SubView (View1, View2, View3, View4 ...) must have a height and distance between each other
P.s. In your case, if iOS > 9.0 you can replace ContentView with UIStackView
You are using auto layout so the size of the content view is determined by constraints. Follow the below steps to provide proper constraints:
Drag the Scroll View inside main view and provide constraints Top, Bottom, Leading and Trailing in align with Super View (Main View) as
per screenshot.
Take View which will contain your content and drag inside Scroll View. and provide the constraints Center X, Center Y, Top, Bottom,
Leading and Trailing in align with Scroll View as per screenshot
Put all the element inside content view which is a subview of scroll view and provide Top constraint relative to the element above
it, to make equal space between the elements (eg. label, button etc.)
(Make sure you provide required constraint for X-position)
Last element is "Register Account" button make sure you provide the Top Constraint relative to country and Bottom constraint relative to
superview (content view) and change the priority for Top or Bottom
constraint as per screenshot, otherwise it gives error.

dynamic height of of scrollview subviews in autolayout ios

I am creating a UIScrollView from xib, in which 3 view are there 2 UIViews and in middle an UIImageView. when I am setting constraints Xcode asked to set Y position constrains. But the problem is Y position constraint is blocking Scrollview to scroll down and automatically adjusting the views which looks ugly in landscape mode.
when I am delete that constraint it ask to fix height of subview. I searched a lot but I am new in autolayout so not understanding many of solutions. any help would be great.
You have to set all the height constraints in the content view.
But you also want the height of the Content to be proportional to the screen size.
To do this assign the height constraint of the imageview [equal|proportional|a-computation-of] to the view containing the UISCrollView.
It seems weird to skip levels of herarchy when assigning constraints between two views whose are not direct ancestor/sibling of each other but within a scrollview (at least) it is perfectly acceptable.
You are basically telling the scrollview that it's content has a known size and at same time setting this content to adapt dinamically to the screen size (if the constraints of the root uiview are set correctly)
UIView1
|---UIScrollView
|---UIView2
|---UIImageView [heightConstr.constant=UIView1.height-UIView2.height-UIView3.height-margins]
|---UIView3
This is the basic idea, to be done programmatically, then you can explore other solutions.
Unfortunately the constraint system in ios pretty much sucks when it's up to more complex equations involving more views for a single constraint.
UIScrollViewcan be tricky when adding constraints. You should always add a subView that will behave as the content view for your UIScrollView and all your subsequent views will go inside this content view.
UIView1
|---UIScrollView
|---UIContentView
|---UIView2
|---UIImageView
Set your UIScrollViewconstraints as you would normally but set your content view to have leading, trailing, top and bottom to the UIScrollView but also add two more constraints which will be equal width and equal height to the viewController.view but will have a low priority (So that whichever direction your content will increase in, that constraint will break and automatically increase the content size of the scroll view by taking in the inferred height of the content view). Now go on and add constraints on all your subview as you normally would. Which i'm assuming would be:
Your topmost view will have top and leading and trailing to its superView and also a fixed height.
Your bottom view will have leading, trailing and bottom to its superView and also a fixed height.
Your UIImageViewwill have a leading, trailing and top to top most view and bottom to the bottom view.
Edit:
Here is the screenshot just in case (To show the view hierarchy with the content view's constraints in the inspector)

How do I add UIView on UIScrollView

I wanted to add some labels and textfields on my view and that view should scroll, so I am thinking of putting view on scrollview.
I wanted to add some labels and textfields on my view
And that view should scroll
So I am thinking of putting scrollView
And then I wanted to put my view having labels and Textfields
Is it possible?
Please check scrollview property Bounces Vertically is checked or not if not check it
May be, your content is less, than ScrollView, that's why scrolling is disabled
Put view with labels in scrollview. Scrollview should be less in height than view. View should have height considering all ui cvontrols in it. should work like this
Make sure your scroll view height is not greater than view its content size has to be greater as all people says. You get confused between content size and scroll view height.
Meas using nib suppose your scroll view height is 300 and when you use the code content size should be greater than 480 so it will be scroll-able on iPhone 4 size device who's height is 480
To make sure your constraints are well defined, first check these steps:
Make sure your base view is a UIView
Put into a UIScrollView and add constraints to the edges of UIView
Put into the scrollview a UIView and add constraints to the edges of the scrollview. I call this "content view".
You should assign a width to the content view. I usually set the width of the content view equal to the width of the scrollview.
Put your labels/views/images/whatever into the content view and use autolayout constraints to resize them automatically to fit the target screen.
Please consider that:
Your scrollview must always have a height, fixed or dynamic. In order to avoid errors with autolayout, consider that:
the last element on the bottom of the content view must always have a constraint to the bottom edge of the scrollview, or
the content view must have a fixed height
If the height of your content view is less than the height of the scrollview, the view will not scroll. You should add more views or more margin to the bottom constraint of the content view.

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