If I set UIScrollView height to self.view.frame.size.height and setAutoresizingMask:UIViewAutoresizingFlexibleHeight then when the view loads the UITabBarController and the UINavigationBar the scroll view frame resizes to suit.
However the content size (set at: self.view.frame.size.height) doesn't change. Fair enough I guess - i can't seem to find an autoresizing option for that, so why would it autoresize.
My fix is to just set the content size as less than the frame height, thus the content will always be the height of the frame. (eg: set content size height to 10points).
I'm just wondering if this is the best way to go about this, or if there's a better way? I'm doing this code in viewDidLoad.
Thanks
Tom
The UIScrollView's contentSize property define the size of the view displayed for Span&Zoom. It normally does not have any relation with the container (i.e. scrollview) size but if you really need to resize the content according to the scrollview size, you can overload the layoutSubViews method to do so.
Related
I have put 14 items in scroll view but it gets stuck after 6 items. I have not put any code, just did all from interface builder (items are arranged vertically). I can see the items below but it jumps to 6 items when I release the touch. It is not that the scroll view is not working, it is just not showing as much I want it to show.
Has any-body got any idea what is happening? any help is appreciated.
You should set the content size of your scrollview.
e.g.
[scrollview setContentSize:CGSizeMake(scrollview.contentSize.width, heigth)];
Where set height that contains all your sub controls in scrollview.
Scrollview content size is not set properly. Use setContentSize: to set the content size of the scrollview
You added the content into scrollview so now you have to make scroll know to what size it shoul scroll and show the content
Do
Set an outlet and then add this code in viewDidLoad
[scrollview setContentSize:CGSizeMake(width, height)];
From Docs
contentSize
The size of the content view.
#property(nonatomic) CGSize contentSize
Discussion
The unit of size is points. The default size is CGSizeZero.
Here is a nice tutorial since you are a beginner .
may be its too late, but here is how i solved it:
put the items in a UIView and stretch that view as much as it need to be stretched.
put that UIView in the scrollview.
put a scroll view in the main uiview, the height and width will be similar to uiview.
Setup: I have a UIView with a scroll view nested within it. Within the scroll view I have a label, uiimage, and a tableview (grouped). The label, uiimage, and tableveiw are populated by a webservice. The last section in the grouped table view contains text that will never be the same and could be as long as 5 characters to 250+. Also, this view is pushed from a basic tableview (so it has a navigation bar. If that matters at all).
Expected: The uiview should extend in height depending on the height tableview extends to. Then I will be able to set the scrollview to accommodate the height I need to be able to scroll.
Problem: I'm not quite sure how to approach the issue. I really only know how to change the height to fixed values, which will not work properly in almost any scenario.
Am I using UIScrollView incorrectly? Do I need to resize the UIView at all?
You don't have to modify your UIView frame size, which has to be the size of your screen. The UIScrollView frame size must also be the same, it represents the part of its view actually displayed.
What must change is the UIScrollView contentSize, which defines height and width for data inside it ;)
You can calculate it using each inside element's height and by adding the correct margin.
Thus, you could have a UIScrollView content size of 320 * 600, which will let you automatically scroll down.
In fact, you have to display your content independently of the final frame size. If you have a content of 500*500, just display it inside your UIScrollView. Then tell it the size of it's content, and it will automatically set scrolling possibilities if needed.
Turns out I had to create a UIView programmatically and set it as the header of the UITableView. It works perfectly now. :)
In IB I have my UIView. Then I have a sub-UIView with a UIScrollView as a sub view. Then the UIScrollView has a sub-UIImageView. The UIScrollView and UIImageView are the same size. They're much bigger than the UIView of which they are subviews. I assumed this would make scrolling work. It doesn't. Is some sort of code required for scroll views to work?
You need to set UIScrollView.contentSize to match the total scrollable size, which is your subview frame size in this case.
As mentioned in the accepted answer, you must set the UIScrollView's contentSize property.
This can be done in Interface Builder.
Select the scroll view
Select the 'identity inspect' in Utilities pane on the right
Under 'User Defined Runtime Attributes' click the '+' button
Set the 'Key Path' value to 'contentSize'
Set the 'Type' value to 'Size'
Set the 'Value' value to '{width, height}' (eg: '{320, 600}')
Build and run and your scroll view will scroll.
The content inset does not affect scrolling. See What's the UIScrollView contentInset property for?
To scroll, you have to make the scrollview's frame smaller than its content, the contained image or view.
This might be obvious to most, but I spent ages wondering why my UIScrollView wouldn't scroll so I'm posting what was stopping me in case it helps anyone else:
The UIScrollView has to be of the dimensions of the visible area in which you wish it to be presented and not the size of it's contents.
Ridiculous on my behalf I know, but just in case it helps someone.
I placed all the content of my scrollview in IB. (buttons, labels, text fields, etc). The full size is 500 tall.
I then resized it to 436 tall in IB.
Then in code, I put this is viewDidLoad:
optionsScrollView.contentSize = CGSizeMake(320,500);
So that leaves 64 pixels that I can scroll. It works perfectly.
I also placed "UIScrollViewDelegate" in the <> braces of #interface for my .h file and tied the delegate outlet of the scrollview to File's owner in IB.
I could solve the scrolling problem with the following answer:
https://stackoverflow.com/a/39945124/5056173
By me the trick was:
You now need to set the height of the content UIView. You can then either specify the height of the content view (blech) or use the
height of the controls contained within by making sure the bottom
control is constrained to the bottom of the content view.
I have set the height and width of the view inside the scrollView with center vertical and horizontal alignment and that was the reason, why it did not work!
After deleting this constraints, I need to add equal width (scrollView and the view inside the scrollView) AND I set the height of the view inside the scrollView directly with the content. Which means: The last element in the view must have a bottom constraint to the view!!
The other important thing that I don't see mentioned here is that UIScrollView does not play nicely with AutoLayout. If it seems like you've done everything correctly, check if your ViewController has autolayout turned on and, if so, turn it off.
(Every time you scroll, the views are re-laid-out. Gak!)
So:
Make sure scrollview's contentSize is bigger than its frame.size
Make sure AutoLayout for the ViewController is turned off.
more, did you enable scrolling?
look at the property
#property(nonatomic, getter=isScrollEnabled) BOOL scrollEnabled
Make sure 3 things,
checking scrollView frame & contentView frame, u may find the answer
scrollView.isScrollEnabled = true
contentView of scrollView height didn't constraint with scroll view height
UIScrollView won't scroll!
reason: contentSize is same as (sub) view
should: contentSize is large than (sub) view
-> UIScrollView can scroll
how set UIScrollView contentSize?
two method:
in code
- (void)viewDidLoad {
[super viewDidLoad];
。。。
//[(UIScrollView *)self.view setContentSize:CGSizeMake(375, 1000)];
CGSize curScreenSize = UIScreen.mainScreen.bounds.size;
CGFloat scrollWidth = curScreenSize.width;
CGFloat scrollHeight = curScreenSize.height * 2;
[(UIScrollView *)self.view setContentSize:CGSizeMake(scrollWidth, scrollHeight)];
in UI (Storyboard)
Storyboard-》Identity Inspector-》User Defined Runtime Attributes-》 add new attribute:
contentSize
Type：Size
Value：{375, 1000}
Scroll view works with this:
Frame
then
contentSize
views or objects etc...
If your frame is set to your content size then it won't scroll.
So set your frame ( in IB right panel -> second last tab 'Size Inspector") to the length of your app ( in my case it is 367 as i have a navbar and a tab bar) then programatically set the contentSize to - yup you guessed it ... more than your frame so it can scroll.
Happy days!!
How can I simply let the scrollview bounce, when the content size is smaller than the view's frame and when I drag it?
like iPhone's app search results.
see UIScrollView (paging mode) bounces only when there two or more pages?
you'd better set the property:
scroll.alwaysBounceVertical = YES;
scroll.alwaysBounceHorizontal = YES;
answer myself: the simplest way would be to set the height of the content size to be the height of the frame plus 1. kind of stupid but according to document it only scrolls when size is bigger than frame.
If you prefer .xib just check Bounce Vertically.
I have a UIView whose height should always be exactly 1.5 times the width. When the view is auto-resized (in this case, because the iPhone is rotated), this proportion gets messed up. How can I make sure the height/width ratio doesn't change as the view resizes?
You need to set the views autoresizingMask property to UIViewAutoresizingNone. This will prevent the size of the view from changing at all when the parent view's size changes (such as when the phone rotates.) If you want the view to resize on rotation, but maintain it's aspect ratio (for example if you want it wider in landscape but still 1:1.5), then you will need to set the view's frame yourself to the desired dimensions (but maintaining the desired ratio) in the view controller's willRotateToInterfaceOrientation:duration: method.
You could implement the -sizeThatFits: method for your view to keep the size in proportion.
Alternatively, you could use a custom superview that implements - (void)layoutSubviews to have complete control over the layout.