I'm currently making a drawing application in Swift, but I wanted the page to be able to expand if the user wanted more room. I figured that I would use a UIScrollView to scroll around the canvas, but I wanted it to expand whenever the user went to the edge of the page, and for the UIImageView that I am drawing on to expand with it. Does anyone know how I would go about doing this?
Thanks!
In storyboard, drag a UIView into your UIScrollView then constrain that view to all sides of the scroll view. Then set the width to whichever value you would like (I would recommend to control drag from your view to the root view of the view controller and select equal widths), then give it a height constraint. Next, you need to connect an IBOutlet to your view controller code for the height constraint you set on the content view inside the scroll view. When you need to extend the page, add to the value of the height constraint and call layoutIfNeeded() on the scroll view.
Related
Please take a look at an image below
There is a scroll view. But I don't want an imageView(topBar) move. How can I keep an image view out of scrollview scope? (I mean fixed topBar, no move) With a constraint? And managing the constraint from code behind during the scroll?
Move the top bar image so that it isn't in the scrollview. It's parent should be the View0 Outlet, then you can constrain it however you want without it moving in then scrollview.
Using a stackView with vertical setting and free form. In this case, you can lock the height of topBar.
I am pretty sure this has something to do with the dreaded AutoLayout. (been trying since 2days to get hang of it)
So I mastered it somewhat, but now I have problem where my UIScrollView is not scrolling fully down, pictures are much better at explaining these things
this is the scroll view
this is the content view
so the problem is the scrolling is happening but then again it springs back up. So I am not able to click on the signup button
EDIt 1
Edit:
I have created a little example on github for you to look at, here. The project illustrates the answer below and uses the techniques I describe and nothing else.
Original Answer:
couple of things I would advise here.
First, I know you've been trying for a while but remove all the current constraints (painful I know but). Do this for clarity as ....
The view should be the size of the scene, it looks like you want the scrollview to be the full screen so that too needs to be the size of the scene.
e.g. if you are designing at 6Plus by default the scene size is 414x736 so the view and the scrollview it contains should also be 414x736.
Only the content view needs to be the size of the real content you wish to show. Let's say for arguments sake that the content is 414x1000.
Now the constraints for the scrollview are simple. It needs zero spacing to all it's edges.
You can add the content view to the scrollview in a couple of ways. The way I try to do this varies from project to project and depends mostly on how complex the scene is. If it's a really busy scene I keep the content view outside of the scrollview in interface builder so that I can work on it easily and visualize the whole of the view. Then I add the content view to the scrollview in code.
If its a simpler view You can add it inside the scrollview in interface builder. Ultimately whichever way you do it, you can lose visibility of the content view in interface builder because the contentview is larger than the scrollview and the content gets obscured. So play about and find a good way for you.
Define the content view and all it's subviews. The content view needs to be taller than the scrollview otherwise it wont scroll. All of the content view's subviews need to have defined heights from top to bottom and widths from left to right. In your case the scrollview is scrolling vertically not horizontally so all the widths need to add up to the width of the scroll view BUT the heights need to add up to the full height of the content view.
Note: if you do this proportially your life will be easier later. If you do all this with fixed heights the storyboard will break on different device sizes.
Now the "tricky bit" and it's a bit counter intuitive. You need to pin the content view to the scrollview, remember the height of the content view is taller than the scrollview. In all other circumstances in Interface Builder pinning a view to a superview (0 padding) will adjust the height (or width) accordingly. For the relationship between a scrollview and it's content view this doesn't happen.
First pin the contentview
Notice the -400? Remember the content view is taller than the scrollview and we will change this immediately.
Select the bottom constraint (-400) that we have just created:
Select the drop down arrow next to the constant value:
Select Standard Value and type in 0 for the constant.
You should now have a storyboard with no broken constraints and if you build and run you should get a scrollview as desired.
Your bottomspace to superview on your content view is set to -74.0, I don't know if there is a reason you had to do that, but try setting it to -8.0. I think your scroll view is scrolling up to the 0.0 mark automatically
How Can I make the green area of the screen shot of my app be able to scroll with the paging animation and page indicators?I would like for me to add more icon-buttons to it with keeping the header the same size.
First you need a scroll view and your view has to be inside of the scroll view.
Then you need to enable paging on the scroll view
[scrollView setPagingEnabled:YES];
If the value of this property is YES, the scroll view stops on multiples of the scroll view’s bounds when the user scrolls. The default value is NO.
If you want to have page indicators you need to use UIPageControlwhich you will have to manage yourself as far as I know. You could always check after scrolling (see UIScrollViewDelegate ) which page you are on based on the contentOffset property of the scroll view.
I'm trying to add a scroll view to an existing screen of my app to help scroll the screen upward when keyboard hides a text field into this view.
I have added the scroll view as a subview of the main view in Interface Builder. Then I added all other objects as subviews to this scrollview. I have set the scroll view size to 320x460 with x=0 and y=0. Now, I notice the layout is broken and all objects (labels,text fields overlap in the same place).
Do you know the proper way to position this scrollview in interface builder so that I can easily position the other objects?
Thx for helping,
Stephane
What you did is correct. It sounds like you moved the other UI elements into the scroll view after you positioned them. In this case they would default to the center position and be overlapped.
If you find it difficult to use dragging in Xcode's Interface Builder, try the position and size tab and type in the coordinates. Alternatively, reposition your UI elements in code.
I have a UIScrollView subclass with a certain subview I'd like to prevent from scrolling (while all the other subviews scroll as normal).
The closest example to this I can think of is UITableView's "index strip" on the right side (look in the Contacts app to see an example). I am guessing this is a subview of the table (scrollview) but it does not move as the user scrolls.
I can't seem to make my subview stay put! How can I accomplish this?
The trick is to adjust the frame of the "non-scrollable" subview inside -layoutSubviews.
Add the view that you want not to move as a sibling view of the scroll view on top of the scroll view instead of as a subview.
You can set it's property called userInteractionEnabled to NO