I am developing a media based application for iOS, It has a scrollview which has three subviews in it - a UIImageView, a title UILabel and a UIButton.
When I scroll the scrollview I want the UILabel to be fixed (i.e it shouldn't scroll with the scrollview) untill the UIImageView scrolls up completely.
Please can you help me, how can I keep the title label frame at a constant height until the scroll view scrolls to a certain height.
I would first make sure the UILabel isn't a subview of the scroll view. Then add <UIScrollViewDelegate> to your view controller class. Then in your .m file add
- (void) scrollViewDidScroll: (UIScrollView *) scrollView
{
CGFloat y = scrollView.contentOffset.y;
if (y > (your number here)) {
// Do something with the UILabel
}
}
Already answered here
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I have a scrollview where I have added different views (like tutorial).
What I wanted to have is slider with below design where on scroll I will see previous tut on left side and next on right side.
For this what I have added is scrollview with paging enabled and adding UILabel (for now) in for loop. After adding label in scrollview below is what I had.
To see the data on the left & right, what I did is uncheck clip subviews from storyboard.
However what I noticed is I can scroll only in scrollview area and not outside.
Any idea how can I make UILabel make scrolling outside & inside scrollview.
As of now to make it working, what I have done is added swipe gesture on view and making scrolling programmatically. However what I was looking is if I scroll outside scrollview, it should scroll scrollview little too.
Phewww...
Finally I managed to make it done..
What I did is added one more scrollview (dummyScrollView) with full screen width above main scrollview (mainScrollView) (which I am using to show label).
Now I enabled paging for the dummyScrollView too and implement below where I am scrolling my mainScrollView based on the factor calculation for the dummyScrollView
#pragma mark - UIScrollView Delegate
- (void) scrollViewDidScroll:(UIScrollView *)sender
{
float myFactor = 0;
// 44232 is tag for new scrollview
if (sender.tag==44232) {
myFactor = mainScrollView.frame.size.width/duplicateSV.frame.size.width;
myFactor = duplicateSV.contentOffset.x*myFac;
CGRect mCC = CGRectMake(myFactor, 0, mainScrollView.frame.size.width, mainScrollView.frame.size.height);
[mainScrollView scrollRectToVisible:mCC animated:NO]; // NO is very important... YES will not work
}
// 44231 is main scrollview tag where I won't be doing anything...
if (sender.tag==44231) {
}
}
I have a complex view hierarchy:
UIScrollView
- UITableView
- UICollectionView
The UICollectionView and UIScrollView both scroll horizontally. Now, I want to capture the swipe gesture exclusively on UICollectionView so that the superview (UIScrollView) ignores it.
User can swipe left to get to the end of UICollectionView. When at the end, the swipe gesture on UICollectionView is ignored and captured by the superview (UIScrollView) and the interface changes. How can I prevent that from happening?
Note: I'm using the default swipe functionality provided by both UIScrollView and UICollectionView i.e. I'm not adding any custom swipe gesture handling.
In your ViewController.m
-(void)viewDidLoad
{
scrollView.delegate = self;
collectionView.delegate = self;
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
if (the scrollView didn't reached the end){
then collectionView can't scroll
}else{
collectionView can scroll
}
}
You can check to see if the scrollView reached the end with the contentOffset property
Don't forget to declare that you are using the delegate of scrollView
Hope that helps
There is a button at the bottom of my view controller. When the user scrolls down the button has to be attached to the scrollview at certain height.
I need to attach a button to the scrollview, immediately when the contentOffset.y reaches a particular value. -(void) scrollviewDidScroll doesn't help me as there might be a jump in contentOffset when the user is scrolling fast. Any leads on this are helpful.
Also, whenever I add a subview to the scrollview, -(void) viewDidLayoutSubviews is called. Which in turn sets the contentOffset to {0,0}. How can I achieve the functionality I need?
I needed to do the same thing with a UITableView and for me using scrollViewDidScroll worked.
I created a view called staticBar and added it as a subview of the tableView, but I had to rearrange the tableview subviews for it to appear in the right place. I don't have my code in front of me, but in -scrollViewDidScroll: it looked something like this:
- (void)scrollViewDidScroll:(UIScrollView*)scrollView
{
CGFloat staticBarAdjustedY = _staticBarY - scrollView.contentOffset.y;
CGFloat scrollViewYFloor = scrollView.frame.size.height - _staticBar.frame.size.height;
// This way maximum Y the view can have is at the base of the scrollView
CGFloat newY = MIN( staticBarAdjustedY, scrollViewYFloor);
_staticBar.frame = (CGRect){ { _staticBar.frame.origin.x, newY}, _staticBar.frame.size}
}
I will check my code later today and add more details here.
Also, you said the scrollviewDidScroll has jumps in contentOffset, but it's worth mentioning that these jumps are the same that the scrollView uses to scroll its own view. So it's not like you are "losing" frames on this delegate method.
Hope it helps.
PS: So, here is the rest of my code.
//I place my custom view as a subview of the tableView below it's last subview
//The last subview is for scroll indicators.
WTButtonsBar *buttonBar = [[WTButtonsBar alloc] init];
[self.tableView insertSubview:buttonBar belowSubview:self.tableView.subviews.lastObject];
In scrollViewDidScroll:
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
//In my app I needed my view to stick to the top of the screen
//thats why I use MAX here
//self.buttonsBarOriginalY is the view's position in the scrollView when it isn't attached to the top.
CGFloat newY = MAX(scrollView.contentOffset.y, self.buttonsBarOriginalY)
[_buttonsBar setFrame:(CGRect){{0, newY}, _buttonsBar.frame.size}];
}
My pure AutoLayout UITableViewCell looks like this in Interface Builder:
UITableViewCell
|-> UITableViewCell.contentView
|-> UIView (ScrollViewContainerView)
|-> UIScrollView
|-> left (fixed)
|-> center (fill remaining)
|-> right (fixed)
The UIScrollView contains a left, center, and right UIView. left and right are both fixed width, while center expands to fill the remainder of the UIView. The UIScrollView constraints are to align all edges to ScrollViewContainerView. ScrollViewContainerView constraints are to align all edges to the UITableViewCell.contentView. I have a constraint on center's width to be a multiple of ScrollViewContainerView's width, so the UIScrollView scrolls left and right, but the height is fixed and does not scroll. Note that the UIScrollView has been subclassed to include this code so that the UITableView can detect a tap on the cell to toggle selection.
The issue is that I currently can either scroll the UITableView containing these UITableViewCells up and down or I can scroll the UIScrollViews in the UITableViewCells left and right, not both.
When ScrollViewContainerView.userInteractionEnabled == YES, I can't scroll the UITableView up and down, but I can scroll the UIScrollView left and right. When ScrollViewContainerView.userInteractionEnabled == NO, I can scroll the UITableView up and down, but I can't scroll the UIScrollView left and right. userInteractionEnabled == YES on everything else in the above hierarchy.
I can get away with having ScrollViewContainerView as a sibling view to the UIScrollView (making the UIScrollView the direct descent of contentView -- can't get rid of this view completely, because I require it to get the dimensions for the UIScrollView frame). In that case, the opposite handling with userInteractionEnabled holds.
I know I've done this before in other projects before, but starting fresh again, I can't seem to figure out what step I'm missing. Currently using Xcode 6 6A215l targeting iOS 8, though I have reproduced the issue under Xcode 5 targeting iOS 7.
It sounds like the scrollview is causing your tableview to not allow userInteraction when being scrolled. I'm sure that if you called - (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView in the UIScrollView delegate (not sure for iOS 8), but you could just do
- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView {
if(scrollView.dragging == YES) {
self.<scrollViewName>.userInteractionEnabled = NO;
}
}
This is untested code, but it's just a bit of help to get you where you need to go.
Hope it helps!
I met some similar problem.
I have a scrollView in tableViewCell. All works fine.
Until one day, someone told me that the tableView can't scroll up/down when finger is touched on the scrollView in 6p. Just in 6p, not in 5, 5s,or6.
This makes me almost crazy.
Finally, I set the scrollView's height smaller than the height in storyboard.
Biu ~ It works~~~
Still, I don't know why.
#user2277872's answer put me on the right track to look at the output of the UIScrollView delegate methods of the UIScrollView in my UITableViewCell subclass. Putting an NSLog() in scrollViewWillBeginDragging: made me notice that the UIScrollView was receiving scrolling events while I was trying to scroll the UITableView. My UIScrollView had a contentSize larger than its frame in both directions, but I've forced that view to only scroll horizontal, so ignored the height and reset it. That force was my undoing and I should have known it at the time -- the correct solution is to fix the frame height. If the UIScrollView doesn't think there is more vertical content, it will correctly forward the swipe up/down gesture to the UITableView.
While I attempt to figure out why my contentSize is too large when it wasn't before (thinking I'm missing a clipToBounds somewhere), what I'm doing to force horizontal scrolling temporarily is (in the UITableViewCell's subclass):
- (void)drawRect:(CGRect)rect
{
[super drawRect:rect];
CGSize contentSize = self.scrollView.contentSize;
contentSize.height = self.frame.size.height;
self.scrollView.contentSize = contentSize;
}
EDIT: Actually, this is seemingly better than overriding drawRect. This would be in the UIScrollView subclass:
/*
* Lock to horizontal scrolling only.
*/
- (void)setContentSize:(CGSize)contentSize
{
[super setContentSize:CGSizeMake(contentSize.width, 1)];
}
The height struct member isn't too important, as long as it's guaranteed to be smaller than the frame.size.height of the UITableViewCell. Still hacky, still need to find why I could clip before and not now.
I have a subclass of UIScrollView class and this scroll have vertical content. But I need drag and drop this UIScrollView in the parent view on horizontal direction. How can I implement this?
You must have a specific hierarchy:
Before you do anything you must go to your StoryBored and deselect the Autolayout option under the FileInspector.
View
ScrollView
ContainerView (if you want one or have one)
View
UIControl (if you have one)
THE CONTENTS OF YOUR VIEW.
You must however make a declaration of the scrollView in your header file:
IBOutlet UIScrollView *yourScrollViewName;
In your main under viewDidLoad:
-(void)viewDidLoad {
yourScrollViewName.translatesAutoresizingMaskIntoConstraints = NO;
[yourScrollViewName setScrollEnabled:YES];
[yourScrollViewName setContentSize:CGSizeMake(320 ,554)]; //320 is the x which is the width. change this to make it horizontal.
//554 is the Height this has to be larger that the screen size in order to have vertical scrolling.
[yourScrollViewName setPagingEnabled:NO];
}