UIScrollView as a subview does not scroll - iphone

When I set my UIScrollView to be the main view within Interface Builder, the scrolling works as expected. However, when I add the UIScrollView as a subview of UIView the scroll does not work.
So it seems my trouble begins when the UIScrollView is added as a subview to UIView.
The "User Interaction Enabled" it true for both view.
I though perhaps I might have to do something with in touchesBegan something lake passing the touches to the UIScrollView, but have not had much luck with that.
Has anyone seen this before?

scrollView.delegate = scrollView; //or nil may work

It's always good to show a complete working code snippet:
// in viewDidLoad:
//UIScrollview *myScrollView;
UIView_descendent *contentView;
// scrollview won't scroll unless content size explicitly set
[myScrollView setContentSize:contentView.frame.size];
I have not found a way to set contentSize in IB.

Related

Storyboard UIScrollView contentSize?

I feel like I have touched on every single possible cause for stopping this, but I have a UIScrollView in my Storyboard hooked up with an outlet and in the viewDidLoad I set the contentSize so that I can scroll (yes bigger than my frame size)!
However, whatever I change, I just can't scroll! I have a couple of textfields in my scrollview and bouncing enabled so I can see that when testing its moves up and down with my subviews in it but whatever I set the contentSize to I just can't scroll.
Anything I might be missing/should check? Is this a known issue with UIScrollView being used in a storyboard?
Whats even stranger is, I can do something like this:
[scrollView setBackgroundColor:[UIColor blueColor]]; and I have a blue scroll view! But setting content size fails.
Edit
My only code (otherwise scrollview is just dropped into storyboard view controller):
-(void)viewDidAppear:(BOOL)animated
{
[scrollView setContentSize:CGSizeMake(320, 640)];
}
Logged frame, comes out as expected:
width: 320.00
height: 504.00
Edit 2
Turns out that removing any subviews of the scroll view in my storyboard lets it scroll just fine. If I add any subview to it at all via the storyboard, even a blank brand new UIButton it just won't apply the contentSize/allow scrolling.
use ViewDidLayoutSubview
- (void)viewDidLayoutSubviews
{
[_scrollView setContentSize:CGSizeMake(320, 500)];
}
UIViewController's method invoke sequence is as below
awakeFromNib
viewDidLoad
viewWillAppear
viewWillLayoutSubviews
viewDidLayoutSubviews
viewDidAppear
viewDidLoad is not a good place to put code that relies on frame sizes of IB objects. If you log the contentSize of your scroll view in viewDidLoad, you will see that it's (0,0). Move the code (where you set the content size) to viewDidAppear, and it will work properly.
Check these
User Interaction enabled
Outlet connected
Included contentsize greater than bounds
scrolling Enabled
eg
scrollView.contentSize = CGSizeMake(320, 640);
My storyboard looks like this for scrollview [working]
I had exactly the same line of code in viewDidAppear and it did not work
Moved it to viewDidLayoutSubviews and it worked correctly.
[scrollView setContentSize:CGSizeMake(320, 500)];
Thanks trick14 for the answer.
The issue is most probably with Auto Layout. UIScrollView needs special attention when using AutoLayout.
Quick-fix - bind one of the scroll's subviews to the top AND bottom space of it's superview (the scroll view).
Long story:
Questions on SO:
UIScrollView not scrolling regardless of large contentSize,
UIScrollView will not scroll, even after content size set,
UIScrollView doesn't use autolayout constraints
Apple's Documentation:
https://developer.apple.com/library/ios/technotes/tn2154/_index.html
Trip14's answer worked for me. In swift I coded it as:
override func viewDidLayoutSubviews() {
(self.view as! UIScrollView).contentSize = CGSizeMake(600, 600)
}
This seems to be a similar issue. Other Story
It might be an issue with auto layout or constraints in the storyboard.
the best way with the storyboard.:

iOS UIScrollView in UIWindow

I currently am making an iOS project in which I have a UIScrollView as a direct subview of a UIWindow (using [window addSubview:scrollView];). The window's frame and its content are being set properly, and the contentSize is set to be bigger than the window's frame. When I try to scroll the UIScrollView, it doesn't scroll at all. Both scrollEnabled and pagingEnabled are set to YES, but the scrollview doesn't scroll, which leads me to believe that the touch/scroll events are not even being received by the scroll view. The window has a UITapGestureRecognizer added to it if it makes any difference. Do I need to somehow forward the swipe events to the UIScrollView, or is there a different reason that it's not scrolling?
EDIT: Here's some code.
float count=ceil([self.msgArray count]/2); //msgArray has length of 3+, NSLog()'d and confirmed.
float contentHeight=97.5 * count;
[dataScrollView setContentSize:CGSizeMake(320,contentHeight)];
dataScrollView.userInteractionEnabled=YES;
dataScrollView.pagingEnabled=YES;
dataScrollView.scrollEnabled=YES;
dataScrollView.clipsToBounds=YES; //Have also tried with this set to NO, or not set at all.
//Add subviews to dataScrollView.
EDIT: Here's some more info.
contentHeight is 195.00 when logged. I've removed the delegate method and I am back to using direct subviews of the scroll view. The window's height is 97.50.
EDIT: I've also removed the UITapGestureRecognizer from the UIWindow, but the scrollview still doesn't scroll.
Ah, the UITapGestureRecognizer! This might be a bug that took me hours to figure out in my own project. Is its cancelsTouchesInView property set to NO like it should be? (YES is the default... It can really throw you off if you're not expecting it.)
Just log the scrollview bounds width/height. The content height you are setting should be greater than the scrollview height. If its more then the scroll view automatically enables its scrolling.

Can't override "hitTest" method for UIScrollView

I've created a scroll view, width less than the screen width and set clipsToBounds=YES. As the UIScrollView doesn't scroll from anywhere outside the range of its frame, I put the UIScrollview inside a UIView and tried to override the "(UIView *)hitTest:WithEvent:" method. But it always shows warning pointInside method not found (or something like that) in the if ([self pointInside:point withEvent:event]) line and it doesn't work. What did I do wrong? Thanks in advance...
You have to change the ScrollView's contentSize in order to allow the ScrollView to scroll. It will only scroll it the contentSize.x is bigger than scrollview.size.x and/or contentSize.y bigger than scrollview.size.y.
Answering my own question, the problem is I didn't create the UIVIew subclass to override the (UIView *)hitTest:WithEvent: while the UIScrollView was in a subview of self.view. So, it is important to check which view inherits the scroll view and write overridden method in the parent view class.

I have a UIView inside of a UIScrollView. How do I reference the parent UIScrollView?

I've finally figured out how to stick a UIView inside of a UIScrollView, but now I have the problem of not being able to call the UIScrollView (who is the parent of the UIView) from within my UIView.
I've tried something like:
UIScrollView *scrollView = (UIScrollView *)self.superview;
But that's not working. My thought process was that the superview would be the container for the current view (UIView), but that returned a UIView so I just casted it to a UIScrollView, which I turned out to not be the right guess.
When you call
[someView addSubview:someOtherView];
someView is automatically set as superview of someOtherView. In your case, if this
UIScrollView *scrollView = (UIScrollView *)[self superview];
does not work (you probably have a typo in your question as the "=" is missing), then you have a problem setting things up (If that's the case, post your setup code).
You can add the scrollView to the UIView, thorough IB or code.
Through code you can add as
[self.view addSubView:scView];
Before that you need to add all the fields, labels and TextFields to the ScrollView. and set tags to the fields for the reference.
if u add textfield in scrollView ...
[scView addSubView: TextFieldsName];

MKMapView inside a UIScrollView doesn't move with swipes

I've got a detail view with various labels and such providing information about a place (address, phone, etc.). The information provided is taller than an iPhone screen so they're all in a UIScrollView (itself inside a UIView) that allows you to swipe up and down to see everything.
I also have an MKMapView inside the scrollview. When it's not attached to anything in Interface Builder it moves up and down with the scrollview, as it should, staying in it's correct relative position to the other controls in the scrollview. You can play with the map, zooming and panning it, etc. and it shows your current location by default.
However, as soon as I hook it to an MKMapView variable in IB, the mapview no longer scrolls with the scrollview. Instead it literally just sits in the position it's originally displayed in (bottom of the view, with a little of the map hidden below the bottom of the view) and the scrollview scrolls up and down behind it.
What's happening here? I've tried changing a bunch of the mapview's and scrollview's properties in IB, but it has no effect. The only thing I haven't tried is just creating the mapview entirely in code, but that doesn't seem like an obvious solution.
EDIT: Sorry to everyone about the expired bounty. I got hung up in other areas of the project and couldn't get back here until now. I didn't know it would expire.
FURTHER EDIT: Well, I figured out my problem. For reasons completely unknown to me I had
[self.view addSubview:mapView];
in the viewcontoller's ViewDidLoad. Once it was hooked up then that line of code would (obviously) make the map a subview of my of view, effectively yanking it out of the scrollview.
Stupid mistake, sorry to have wasted your time (and the bounty). I'll delete this question after I think the answerers have had a chance to see the result.
Looking like as you are using the ScrollView,you need to scrolling facility in your DetailView.
Instead of using the ScrollView ,I had an alternative of this ....
You can try your hard luck by using the TableView instead of ScrollView.
Just take all the labels and mapView in a single View and then put that view in the header of the TableView.
like this :
UITableView
--> View
------>All Labels // Inside the singleView
------>MKMApView // At bottom of the View
Still You can play with the map, zooming and panning it, etc. and it will show your current location by default.
Hope this alternative can solve your problem.......
All the Best
If hooking up an outlet in IB is breaking an otherwise working view, you might be able to try this to locate the view at runtime:
- (UIView *) findClass:(Class) aClass inView:(UIView *) aSuperview {
for ( UIView *view in aSuperview.subviews ) {
if ( [view isKindOfClass: aClass] ) break;
if ( ( view = [self findClass: aClass inView: aSuperview] ) ) break;
}
return view;
}
- (void) viewDidLoad {
MkMapView *map = [self findClass: [MkMapView class] inView: self.view];
}
I figured out my problem. For reasons completely unknown to me I had
[self.view addSubview:mapView];
in the viewcontoller's ViewDidLoad. Once it was hooked up then that line of code would (obviously) make the map a subview of my of view, effectively yanking it out of the scrollview.
Do you have setContentSize property set to the content's size in the viewDidLoad method of the UIViewController?