Dynamic-sized UIView inside a UIScrollView - ios

For my application, I need to add several dynamic-sized UIViews to a global UIScrollView. I want the subviews to position themselves one on the top of the others.
To simplify and be able to reuse my subviews, I made them as separated ViewControllers that I insert into my global ScrollView inside a Container View. They all look alike: a title label, which has a fixed height, a button at the bottom, and in between, a CollectionView or a TableView which has a variable height, which are all embedded inside a ScrollView so that I can compute the size with the contentSize
The structure of the view is the following:
[ScrollView]
[Header view (fixed size)]
[Container View #1]
[Container View #2]
...
[/ScrollView]
I would like the global WebView to resize according to the items inside it, and the containerViews to resize according to the content of the main view of the VC they embed.
My problem is that I can't get the correct size of my subviews: the contentSize of the embedding ScrollView of the components is not correct: either the width or the height is incorrect.
I added constraints between the elements, which seem to work, but when I try to get the contentSize of the scrollview of the components, the height that I get is the size of the height constraint of the embedding container view, which is not logical, because the content inside the scrollview is much taller, thus the scrollview allows scroll

I found the bug
The sizes of the scrollViews were incorrect because I needed to call layoutIfNeeded() on the scrollViews, perhaps because they were embedded inside separated VCs

Related

Resize view in UIScrollView

I am so confused about UIScrollView.
I'm working with a view contains many other views. And that view placed in a UIScrollView.
How can I change height of this view?
I've tried so many ways but they didn't work. I tried to change frame by CGRect but view's child went wrong.
First of all you should be using constraints using auto layout.If all the constraints are justified then the there will be no warning.At that moment the scrollview will fit all the views under its contents view and mange the content size of it by itself.
If you want to increase any view in the scrollview to increase in height you may increase the height constraint and the scrollview will manage the constentsize by itself.

UIScrollview Height dynamic based on views ios

I'm writing an ios application, which has child views (like fragments or subviews) which are placing in a simple UIView in a UIViewController and the height of UIView is approx 300px. Im just loading subviews in UIView, however every subview has its own content that may not be fit in 300px thus uiscrollview cannot got though out the last view.
My problem is, Im unable to solve the scroll view content in order to scroll from parent UIViewController along whith its child view controller subviews, as the subviews are longer than 300px and thus uiscrollview is unable to get te last element.
I tried to to give static scrollview.contentSize.height = 1000 and hence the scroll view can scroll below the screen but im unable to click on the later views as it seems uiscrollview is unable to read that element.
My question is, how can i assign dynamic uiscrollview height assuming that im using autolayout in my uiviewcontroller and I want to calculate scroll height according to children based in my UIViewController. Im using swift 2.0 and autolayout in storyboard.
Your constraints should be like,
scrollview - top,bottom,leading,trailing
view (content view) - top,bottom,leading,trailing,fix height and horizontally center in container
and add your all other stuff in that view. you will got desired result. it will scroll in small screen size then content view and will not scroll for bigger screen then content view.
second thing you need to increase height of your content view as more subviews add. your content view's height should be equal to all subview's height and spacing
After this setup if you unable to scroll then check content view's bottom constraint's constant in size inspector. make it zero (if unable to scroll then only).
hope this will help :)

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.

IOS : Make entire view scrollable, not only subview

I have a viewController in which I have a scrollView in which I have 3 views. This is a scheme :
ScrollView (UIScrollView)
Header (UIView)
TabBar (UIView)
Container (UIView in which I load a ViewController)
The main problem is that, in my container (in which there is a view controller), I have a collectionView (which can scroll) but I want my entire scrollView to scroll (not only my container).
So this is what I have :
And this is what I want :
Anyone can help me with this ?
I just solved this problem for my own project. Assuming you are using storyboards, I made the UIView a child of UITableView and made the UITableView extend the full viewport of the device.
Since UITableView implements UIScrollView you get full screen scrolling of your content.
General Rule your parent view has to implement UIScrollView and extend the full screen to get viewport vertical scrolling.
To do this, if you are not using auto layout or if you are adding views to container programmatically, you must manually set collection view frame to match its content size after you load some data on it. If you are using auto layout, you should create height constraint outlet and set its constant value based on collection view content size, again after loading data on it
You should set the frame of the container view to match the height of the view controller that it is loaded in it and set the contentsize of the scroolview based on the container height.
A scrollview will scroll only if its contents are bigger than its frame. This applies to the parent scrollview as well as the child scrollview.
Here in your case, for the parent scrollview to scroll its contents (Header, Tabbar & container) together must have greater height than its parent. The child scrollview (container) is already scrolling because its contents (a view controller) has greater height than its parent.
I have made both scroll views to scroll:
(1) The parent scrollview - by increasing the height of the child scrollview so that it extends below the main view controller's frame. The child scrollview is one of the contents of the main scrollview.
(2) The child scrollview - Setting a large content inside it so that it is bigger than its parent. I have used a long UIImage as its content.
Also, I have used autolayout and pinned the contents to the scrollviews' sides by adding constraints.
Hope this helps.
This is how it scrolls: Scrolling of UIScrollView inside another

How to make a ScrollView with AutoLayout in Xcode5

In xcode 5 using storyboards how would one make a fully operational vertical scrolling scrollview, with AutoLayout ON?
Considering the subviews have hierarchy:
1.UIView
2.UIScrollView
3.UIView (lets call this UIDetailView to make things easier)
Please be specific from code to constraints to wether any of the views HAS to be smaller etc.
UIScrollView with Autolayout within Storyboards Just Works
I've seen a number of people recommending the 'Container View' approach, AKA brute force, to solving the problem that they don't understand. It is non-optimal since you now have lost a big advantage of the scrollview by making it think the content is the entire scrollview rather than the subviews immediately attached to the scrollview.
Here is how I did it in the example that follows
--UIScrollView
|-> UITextView
|-> UILabel
|-> UIOtherStuff
When placing a UIScrollView into a UIView in a Storyboard just pin the edges to the 4 sides of the UIScrollView to the UIView. Now add your content to the UIScrollView making sure that you provide a minimum of two constraints for each dimension. The great thing about Autolayout is that it figures out how big the contentSize of the scrollview, or UILabels for that matter, needs to be based upon the size of the content inside it. AKA intrinsicContentSize. So if you are given a warning 'Ambiguous content size for scrollView' you know that you have not given the content enough constraints. For example, you might have given Top, Bottom, Left, Right spacing distance between views but the subview you're constraining needs a height too since an infinite vertical plane like this UIScrollView could assume your view was from zero to infinitely high.
To put it another way the Apple guide on Autolayout by Example makes a simple 3 point plan for success:
Create the scroll view.
Place the UI element inside it.
Create constraints that fully define the width and height of the scroll view content.
That top TextView with 'Min melding til' is also growing as you type more lines into it and the whole ScrollView grows to contain it. While I override the UITextView class to return a modified height constraint, the ScrollView itself works correctly without coding.
One last thing, lots of posts related to Autolayout try the magical fix-all incantation translatesAutoresizingMaskIntoConstraints = NO. This is only necessary if the view is created programmatically.
This blog post details how to use a UIScrollView with Autolayout ON, using a pure autolayout approach. Note though that all constraints in the blog post are defined through the Storyboard.
The approach in the post assumes the following hierarchy:
1. View (main view of my UIViewController)
2. Scroll View (UIScrollView)
3. Container View (UIView)
4. Content View (e.g. UIImageView)
I guess the Container View will be your UIDetailView, and the Content View will be any UIView inside your UIDetailView.
https://happyteamlabs.com/blog/ios-how-to-use-uiscrollview-with-auto-layout-pure-auto-layout/
The documentation clearly states how to do this:
A UIScrollView in auto-layout will always resize itself to fit the content (UIDetailView).
So you have to set up your views like this:
UIView: Position with constraints.
UIScrollView: Bind to UIView with constraints.
UIDetailView: Set size (intrinsic content size), max out compression-resistance, set top-, bottom-, leading- and trailing constraints to UIScrollView to 0 manually.
I had a similar problem and i found relative simple solution similar to DJ S's from within Interface Builder using pure Autolayout without any code.
For proof-of-concept at first remove any constraint in View Controller to if see this works.
This is sample layout:
View (main view of my UIViewController)
Scroll View (UIScrollView)
Container View (UIView)
Content View (e.g. UIImageView)
A. Scroll View width/height should be smaller that Container View width/height
B. Container View should have some determinated width/height (may be explicit width/height )
C. Do Control-drag Container View to Scroll View and add only:
Leading Space to Container
Trailing Space to Container
D. Check out those two constraints and set "constant" value for both to 0
E. Run app and
Because of the new iPhone 6 and 6+ screen sizes, I had to make a few tweaks to DJ S's solution.
The goal
Position a UITextView inside a UIScrollView, and also have 15 pt spaces from the left/right screen edges.
Views
1. Main View (main view of my UIViewController)
2. Scroll View (UIScrollView)
3. Container View (UIView)
4. Text View (UITextView)
Solution
For the spaces, I added 15 pt horizontal trailing/leading spaces from UIScrollView->Main View. To make the UITextView's width relative to the screen width, I added an Equal Widths constraint from UITextView -> Main View and set the value to -30 (2 * the 15 pt horizontal space). Now, the UITextView's width will dynamically adjust for any screen size.
The UIScrollView should have Scrolling Enabled. The UITextView should not.

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