How should I set constraint of UICollectionView in iOS - ios

Hi I want to put CollectionView in fullScreen
So I set it's constraint all top, buttom, left, right zero with SafeArea
But in iPhone 11, When I put many Items, CollectionView Cover the SafeArea with scroll
And I can't see last Item fully
I can see the Item when I scroll, but it bounce up immediately
When I set HeightConstraint with Constant, same height with SafeArea, It looks perfect
So I guess the reason of problem is that Height of SafeArea be changed when CollectionView require Scroll
Any Suggestion for this?
If I can, I want to solve it with StroyBoard
First screen is Auto Layout that I set on Storyboard
And Second One is current Work
I can't see the bottom of Last Cell , I can see if I scroll down, But It Bounce up like that

In your view hierarchy, I noticed a header view is residing for your collection view. Have your tried defining it's height using referenceSizeForHeaderInSection method? You will find that method in collectionViewLayout. Here's reference link :- https://developer.apple.com/documentation/uikit/uicollectionviewdelegateflowlayout/1617702-collectionview

Related

Scrollview not working properly on iPad in xcode(iOS)

Recently, i've been building and app which requires a scrollview, for all the content to fit. I've had a few difficulties creating my scrollview. I've tried a few different methods for building it, but ended up building it in storyboard with autolayout. I've set the height of the view controller to 1000, and therefore also the simulated size to freeform. The width of the content view inside the scrollview, I've to the same as the view which contains the scrollview.
The hierarchy goes like this:
-View controller scene
-Top layout guide
-Bottom layout guide
-View
-Scroll view
-Content view
-Label with text here
-Constraints
-And so on
I've been replicating the process in this link, to create the scrollview:
https://www.ralfebert.de/snippets/ios/auto-layout-recipes/uiscrollview-storyboard/
When running the application on the simulator, I get the following result:
The scrollview is not working properly on the iPad. It seems like the scrollview doesn't adapt to the changes in the width, which happens when its ran on an iPad, since it's bigger. When the app is ran on the iPad, the scrollview stays the same width as if it were shown on the iPhone.
This is how it looks in the editor. The view controller on the left is the view controller which has the scrollview implemented, and the one on the right doesn't. The first image shows the storyboard, when I view it with the iPhone 8, and the second image is when I view it with an 9,7" iPad:
It would be greatly appreciated if anyone could give me a hint to whats going on!
EDIT:
Left side is what it looks like, and right side is what it should look like:
Add the UIScrollView to your main view
Set Top, Left, Right, Bottom constraints all to Zero
Add a UILabel inside the scroll view
Set number of lines to Zero
Set Top, Left, Right, Bottom constraints all to Zero
Set the label's width constraint equal to the scroll view's width
That should do it :)
This will keep the label's text aligned to the top of the scroll view. If you add enough text to fill more than the full screen, it will scroll vertically.

Tableview ContentView Cell label constraints displaying incorrectly

Currently I'm displaying two labels and view on a tableview contentview cell on my app. Without constraints, the labels display correctly on the device. However, when I add constraints to the labels in the storyboard, they always align to the left. I'm currently using top, bottom, leading/trailing (left & right), and have in other attempts also set height and width.
New Constraints storyboard:
However, when I run it on any device, it always looks like this:
Actual view:
I'm wondering why this keeps happening. I want to avoid doing constraints programmatically in this app to show I can use storyboard, but this one problem has stumped me. I've tried reading up as much as I can, but I just can't get it to work. Any idea how to get it to look like the first picture, all the time when, adding constraints?

UItableview auto height bug when label constraint to bottom

Im using a UItableview with auto height, i have 3 labels : label, sublabel and price. on top of the table i have a view attached to the bottom of screen. when scrolling the table down, it auto hides, when coming back up it shows again (kinda mimics safari functionality..) , heres comes the glitch. if i pin the sublabel to the bottom. ( as everybody knows if you are using cell auto height you have to.. otherwise the text will just mess up and the height of the cell won't change... . my bottom bar view will hide when scrolling , but when scrolling some more it glitches and pops back out for half a second, this only happens only when time, that first time the view appears...
im kind of stuck on this, i cannot unpin the sublabel, cause it will mess the cell height, etc. and i cannot have this glitch on messing up either... is there another way to make the auto height on cell work ?
This is the basic layout. as you can see.. normal table view a a view on top which fixes to the bottom.
constraints.
Everything has their constraints for good. In this picture i deleted the bottom constraint and the top constraint to Label of the sublabel (i decided just not to display the sublabel text while i figure this bug out..) Thats when the bug happen (if enabled). In this in table im using auto/ dynamic height. the label and the sublabel are settled lines to 0, wordwrap by word and they have their constraints ok. i have a mechanism that when user scrolls down. the Bottom bar hides down, if the user comes back to top of the table, the bottom bar shows up. so the thing is, for the uitable cell to auto height u really need 2 must constraints. one top, one bottom. if i eliminate the bottom constraints like in the pic. the bug from the bottom bar flicking disappears but i don't get my table cell auto weighted so the text will mess up... if enabled then i get the flicking bug one time, that first load. then it works normally

With Storyboards only, how do I create a UITableViewCell that can scroll left and right using UIScrollView?

Similar to Mail.app where you can scroll the cells side to side, I want to be able to do it in my app using Storyboards and UIScrollView with my UITableViewCell.
I add some buttons to the contentView of my cell, and then UIScrollView with an embedded UIView on top of that to contain the main portion of the cell. I then add a label to that.
I understand that scroll views in Storyboard work by specifying constraints to show what the contentSize of the scroll view should be.
So I position the UIView in the UIScrollView to be the same width and height of the scroll view, but give it a trailing constraint of say 50pt to allow the scroll view to scroll. When I run it I can then move the cell to the left to reveal the buttons.
But to get it work in the other direction I have no idea. If I add a leading constraint it actually moves the cell to begin with away from the left, offsetting the cell to begin with when it should be left to the user to scroll it. It works fine other than initially being pushed over.
I created a sample project showing it here: http://cl.ly/2i3m1W2T0i3C
Like I said I just can't seem to figure out how to get it to scroll in both directions.
Try setting the contentView of the scrollView with width higher than the scrollView itself.
Something like:
Assuming your scrollView.frame is (0,0,100,100)
[scrollView setContentSize:CGSizeMake(300,100)];
place your table view, let a part of your view out of the screen and check that case:

How to use UIScrollView in Storyboard

I have a scroll view with content that is 1000px tall and would like to be able to lay it out for easy design on the storyboard.
I know it can be done programmatically but I really want to be able to see it visually. Every time I put a scroll view on a view controller it won't scroll. Is it possible to get it to work like I want or do I have to do it in the code?
I'm answering my own question because I just spent 2 hours to find the solution and StackOverflow allows this QA style.
Start to finish here is how to make it work in storyboard.
1: go to you view controller and click on Attribute Inspector.
2: change Size to Freeform instead of Inferred.
3: Go to the main view on that storyboard, not your scrollview but rather the top level view.
4: Click Size Inspector and set this view to your desired size. I changed my height to 1000.
Now you will see that you storyboard has your view setup so you can see the entire height of your scroll for easy design.
5: Drop on a scrollview and stretch it so it takes up the whole view. You should now have a scrollview with size of 320,1000 sitting on a view in your view controller.
Now we need to make it scroll and need to make it show content correctly.
6: Click on your scrollview and click on Identity Inspector.
7: Add a User Defined runtime attribute with KeyPath of contentSize then type of SIZE and put in your content size. For me it is (320, 1000).
Since we want to see our whole scroll view on the storyboard we stretched it and it has a frame of 320,1000 but in order for this to work in our app we need to change the frame down to what the visible scrollview will be.
8: Add a runtime attribute with KeyPath frame with Type RECT and 0,0,320,416.
Now when we run our app we will have a visible scrollview has a frame of 0,0,320, 416 and can scroll down to 1000. We are able to layout our subviews and images and whatnot in Storyboard just the way we want them to appear. Then our runtime attributes make sure to display it properly. All of this without 1 line of code.
Here are the steps with Auto Layout that worked for me on XCode 8.2.1.
Select Size Inspector of View Controller, and change Simulated Size to Freeform with height 1000 instead of Fixed.
Rename the view of View Controller as RootView.
Drag a Scroll View as subview of RootView and rename it as ScrollView.
Add constraints for ScrollView:
ScrollView[Top, Bottom, Leading, Trailing] = RootView[Top, Bottom, Leading, Trailing]
Drag a Vertical Stack View as subview of ScrollView and rename it as ContentView.
Add constraints for ContentView:
ContentView.height = 1000
ContentView[Top, Bottom, Leading, Trailing, Width] = ScrollView[Top, Bottom, Leading, Trailing, Width]
Select Attributes Inspector of ContentView, and change Distribution to Fill Equally instead of Fill.
Drag a View as subview of ContentView and rename it as RedView.
Set Red as the background of RedView.
Drag a View as subview of ContentView and rename it as BlueView.
Set Blue as the background of BlueView.
Select RootView, and click Update Frames button.
Update Frames is a new button in Xcode8, instead of Resolve Auto Layout Issues button. It looks like a refresh button, located in the control bar below the Storyboard:
View hierarchy:
RootView
ScrollView
ContentView
RedView
BlueView
View Controller Scene (Height: 1000):
Run on iPhone7 (Height: 1334 / 2):
Here are the steps that worked for me on iOS 7 and XCode 5.
Drag a ViewController (it comes with UIView "View").
1.1 Select "View Controller" and select "File Inspector" and uncheck "Auto layout".
Drag a ScrollView (as child of ViewController's UIView "View")
Select ScrollView and open "Identity Inspector".
Enter "contentSize" for keyPath. Select "Size" for Type. And Enter {320, 1000} for value.
Note: Step 4 is simply saying that the scroller contains some content whose size is 320x1000 units. So setting contentSize will make scroller work.
Select View Controller, Select "Attributes Inspector" then select Freeform from Size.
Note: step 5 will allow us to change the size of "View" that the view controller comes with.
Select "View" and then select "Size Inspector".
Set Width to 320 and height to 1000.
Note: 5, 6 & 7 is purely for us to see stretched or entire expanded view inside StoryBoard.
Note: Make sure to unselect "Auto Layout" on View Controller.
Your View hierarchy should look like:
After hours of trial and error, I've found a very easy way to put contents into scrollviews that are 'offscreen'. Tested with XCode 5 & iOS 7. You can do this almost entirely in Storyboard, using 2 small tricks/workarounds :
Drag a viewcontroller onto your storyboard.
Drag a scrollView on this viewController, for the demo you can leave its size default,
covering the entire screen.
Now comes trick 1 : before adding any element to the scrollView, drag in a regular 'view' (This view will be made larger than the screen, and will contain all the sub elements like buttons, labels, ...let's call it the 'enclosing view').
Let this enclosing view's Y size in the size inspector to for example 800.
Drop in a label onto the enclosing view, somewhere at Y position 200, name it 'label 1'.
Trick 2 : make sure the enclosing view is selected (not the scrollView !), and set its Y position to for example -250, so you can add an item that is 'outside' the screen
Drop in a label, somewhere at the bottom of the screen, name it 'label 2'. This label is actually 'off screen'.
Reset the Y position of the enclosing view to 0, you'll no longer see label 2, as it was positioned off screen.
So far for the storyboard work, now you need to add a single line of code to the viewController's 'viewDidLoad' method to set the scrollViews contents so it contains the entire 'enclosing view'. I didn't find a way to do this in Storyboard:
- (void)viewDidLoad
{
[super viewDidLoad];
self.scrollView.contentSize = CGSizeMake(320, 800);
}
You can try doing this by adding a contentSize keyPath as a size to the scrollView in the Identity Inspector and setting it to (320, 1000).
I think Apple should make this easier in storyboard, in a TableViewController you can just scroll offscreen in Storyboard (just add 20 cells, and you'll see you can simply scroll), this should be possible with a ScrollViewController too.
Getting Scrolling to work in iOS7 and Auto-layout in iOS 7 and XCode 5.
In addition to this: https://stackoverflow.com/a/22489795/1553014
Apparently, all we need to do is:
Set all constraints to Scroll View (i.e. fix scroll view first)
Then set distance-from-scrollView constraint to the bottom most item to scroll view (which is the super view).
Note: Step 2 will tell storyboard where the last piece of content lies within Scroll view.
For this example, I have unchecked the Autolayout feature of the Interface builder. And, I'm still using (for no reason at all) the relatively old 4.6.1 version of Xcode.
Start with a view controller that has a scroll view over it (the main view).
1: Add a Container View, from the Object Library, to the scroll view. Notice that a new view controller is added to the storyboard and it is linked to the view controller with the scroll view.
2: Select the container view and, on the Size Inspector, make it anchor to top and left without auto resizing.
3: Change its height to 1000. (1000 is used for this example. You should apply the value that you require.)
4: Select the new view controller and, from the Attributes Inspector, change Size to Freeform.
5: Select the view of the new view controller and, on the size Inspector, change the height to 1000 (which is equal to the container view's height).
6: For your test later, while still on the view of the new view controller, add a label at the top and at the bottom of the view.
7: Select the scroll view from the original view controller. On the Identity inspector, add an attribute with the keyPath set to contentSize, type set to Size, and value set to {320, 1000} (or your container view's size).
8: Run on the 4-inch iPhone Simulator. You should be able to scroll from the top label up to the bottom label.
9: Run on the 3.5-inch iPhone Simulator. You should be able to scroll from the top label up to the bottom label.
Remember that Xcode 4.6.1 can only build for iOS6 and below. Using this approach and building for iOS6, I am still able to achieve the same results when the app is run on iOS7.
Note that within a UITableView, you can actually scroll the tableview by selecting a cell or an element in it and scrolling up or down with your trackpad.
For a UIScrollView, I like Alex's suggestion, but I would recommend temporarily changing the view controller to freeform, increasing the root view's height, building your UI (steps 1-5), and then changing it back to the standard inferred size when you are done so that you don't have to hard code content sizes in as runtime attributes. If you do that you are opening yourself up to a lot of maintenance issues trying to support both 3.5" and 4" devices, as well as the possibility of increased screen resolutions in the future.
Disclaimer :- Only for ios 9 and above (Stack View).
If you are deploying your app on ios 9 devices use a stack view.
Here are the steps :-
Add a scroll view with constraints - pin to left, right, bottom, top (without margins) to superview (view)
Add a stack view with same constraints to scroll view.
Stack View Other Constraints :- stackView.bottom = view.bottom and stackView.width = scrollView.width
Start adding your views. The scroll view will decide to scroll based on the size of the stack view (which is essentially your content view)
Here's how to setup a scrollview using Xcode 11
1 - Add scrollview and set top,bottom,leading and trailing constraints
2 - Add a Content View to the scrollview, drag a connection to the Content Layout Guide and select Leading, Top, Bottom and Trailing. Make sure to set its' values to 0 or the constants you want.
3 - Drag from the Content View to the Frame Layout Guide and select Equal Widths
4 - Set a height constraint constant to the Content View
i wanna put my 5 cents to accepted answer:
i've been researching topic for 2 days and finally found a solution that i will be using always from now on
go up to item 4 in accepted answer and forget about adding attributes of frames and contentsizes and so on
to make everything automatic just use solution from this link
everything is clear, easy, elegant and works like a charm on ios 7. i'm pretty glad with all that lol
You should only set the contentSize property on the viewDidAppear, like this sample:
- (void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];
self.scrollView.contentSize=CGSizeMake(306,400.0);
}
It solve the autolayout problems, and works fine on iOS7.
Here is a simple solution.
Set the size attribute of your view controller in the storyboard to "Freeform" and set the size you want. Make sure it's big enough to fit the full content of your scroll view.
Add your scroll view and set the constraints as you normally would. i.e. if you wants the scroll view to be the size of your view, then attach your top, bottom, leading, trailing margins to the superview as you normally would.
Now just make sure there are constraints in the subviews of the scrollview that connect the top and bottom of the scroll view. Same for left and right if you have horizontal scrolling.
In iOS7 I found that if I had a View inside a UIScrollView on a FreeForm-sized ViewController it would not scroll in the app, no matter what I did. I played around and found the following seemed to work, which uses no FreeForms:
Insert a UIScrollView inside the main View of a ViewController
Set the Autolayout constraints on the ScrollView as appropriate. For me I used 0 to Top
Layout guide and 0 to Bottom layout Guide
Inside the ScrollView, place a Container View. Set its height to whatever you want (e.g. 1000)
Add a Height constraint (1000) to the Container so it doesn't resize. The bottom will be past the end of the form.
Add the line [self.scrollView setContentSize:CGSizeMake(320, 1000)]; to the ViewController that contains the scrollView (which you've hooked up as a IBOutlet)
The ViewController (automatically added) that is associated with the Container will have the desired height (1000) in Interface Builder and will also scroll properly in the original view controller. You can now use the container's ViewController to layout your controls.
Here's a bit of a grubby answer that get's to the same solution for vertical scroll views, but (against the ethos of stackoverflow) doesn't answer the question. Instead of using a scrollView, just use a UITableView, drag a normal UIView into the header, and make it as big as you want, you can now scroll the content in storyboard.
Apparently you don't need to specify height at all! Which is great if it changes for some reason (you resize components or change font sizes).
I just followed this tutorial and everything worked: http://natashatherobot.com/ios-autolayout-scrollview/
(Side note: There is no need to implement viewDidLayoutSubviews unless you want to center the view, so the list of steps is even shorter).
Hope that helps!
The key is the contentSize.
This is often missing and not indicated when adding a UIScrollView.
Select the UIScrollView and select the Identity Inspector.
Add a contentSize keyPath as a size to the scrollView in the Identity Inspector and setting it to (320, 1000).
Scroll away.
If you are using auto-layout than best approach is to use UITableViewController with static cells in storyboard.
I have also once faced the problem with a view that require much more scrolling so change the UIScrollView with above mentioned technique.

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