I have a UIScrollView which I create and size dynamically using...
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width , length);
I then add subviews to the UIScrollView.
I do have scrollView.showsVerticalScrollIndicator = YES;
When scrolling the scroll indicator never appears.
Even if I call [scrollView flashScrollIndicators] nothing happens.
Ideas?
Had the same problem and couldn't find the cause. The last answer gave the final hint: whenever I added new subviews I first removed all existing subviews from the scrollview (and apparently also the scroll indicators).
After checking in my loop, if the subview really was of the kind I wanted to be removed the scroll indicators showed up:
for (NSObject * subview in [[[scrollView subviews] copy] autorelease]) {
if ([subview isKindOfClass:[MySubView class]]) {
[(MySubView*)subview removeFromSuperview];
}
}
Update: changed code to Nikolai's suggestion
When I've dealt with this before, in my implementation of a grid, I would occasionally get some cells over the top of the scroll indicator. To fix this I am now inserting subviews at index 0 rather than adding them, which adds them to the top. So try something like this:
[scrollview insertSubview:subview atIndex:0];
For me, the horizontal indicator had mysteriously disappeared in my app on iOS 7. Later found out that for some strange reason, I had to enable both Shows Horizontal Indicator and Shows Vertical Indicator to make the horizontal one show up. If I set it to not show the vertical indicator, it would also not show horizontal indicator.
I fix this by adding this code after add new subview:
self.showsVerticalScrollIndicator = NO;
self.showsVerticalScrollIndicator = YES;
It will also happen (at least in the case of a UITableView) if the contentSize is too small for the table view to scroll. If you have enabled bouncing, then the tableview does not actually scroll and does not display the indicators therefore. Try fitting more content inside.
It can happen also if the parent of the scrollview is smaller horizontally than the scroll view itself :
The scroll bar is stuck to the right side of the ScrollView / TableView and this right side is not visible due to the parent bounds ( with a clipToBounds hidding it for instance).
I've seen this issue so I share it in case it can help.
Just check the width of your ScrollView's frame not to be bigger than the width of its parent view frame.
Two conditions,
If you are using a storyboard
If you are using a UITableView inside a UIViewController
Then, you should check your indicator insets are set to 0 (or any other number that is relevant to your autolayout):
Noticed this when the UIScrollView was a 48 px tall horizontal band, scrollable horizontally. Maybe Cocoa decides the area is too small for a scroll indicator...
Related
i am looking to create an "options" page for my application and because they are many , the screen of the phone is not enough to show.
So i need the user to be able to scroll down the view to see more options till the last. I know i should use the scrollview , but i dont know how.
All the tutorials i ve found are about scrolling all over the screen , zooming , scrolling from left to right , but nothing on how u can create a simple page scrolling up and down.
How exactly do i do that? Do i make many .nib files and somehow i connect them? Do i make a big .nib file?
Can someone guide me to a tutorial on that?
Use ContentSize property of UIScrollView to scroll what ever area you want. i.e.
take UIScrollView add it on UIView with exist height of iPhone. i.e. max 460.0
So ScrollView frame will be max (0,0,320.0,460.0).
Now after adidng ScrollView to View set ContentSize property to upto scrollable area.
[self.mainScrollView setContentSize:CGSizeMake(self.mainScrollView.frame.size.width, 1000.0)];
UIScrollView *mainScroll = [[[UIScrollView alloc]initWithFrame:CGRectMake(x,y,w,h)]autorelease];//scrollview width and height
mainScroll.scrollEnabled = YES;
mainScroll.userInteractionEnabled = YES;
mainScroll.showsVerticalScrollIndicator = YES;
mainScroll.contentSize = CGSizeMake(width,height);//width and height depends your scroll area
..........
//add subviews to your scrollview.....
[mainScroll addSubview:view1]
............
[mainScroll addSubview:view2]
..............
[mainScroll addSubview:view3]
[self.view addSubview:mainScroll];
Note :: contentSize property determines your scroll
area.Scrolling
enabled only if your scrollview content larger than scrollview height..
You could use a Table View with static Cells, that will scroll automatically if it needs to, much easier. Also with a Table View you can choose to scroll up, down, left, right, set bouncing etc from the Attributes Inspector.
Make only 1 nib file.
give height of scroll view large as you want.
then place your buttons , textfeild on scroll view
There are two ways :
make settings bundel for your app check this Press Me
to make UITableView with custom cells >> it is easy if you use
Interface Builder Press Me
I have around 13 UITableViews on UIScrollview,scrollview scrolls horizontally and shows all uitableviews.
on each scroll I want to scroll to particular point and i did that using the code
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
if(position >= 12)
position=-1;
position++;
[self scrollToPosition:position];
}
-(void)scrollToPosition:(int) tempPos{
[scrollView setContentOffset:CGPointMake(635*tempPos+tempPos*5, 0)];
}
Problem is: How can I detect whether I scrolled to left or right ??
as per my code whatever direction of the scroll it'll just increase contentOffset, But I want to achieve left scroll as well as right scroll along with setting particular contentOffset to each scroll.
Also, If i scroll any of my uitableViews vertically, then these delegates will get called and set the contentOffset so that it'll scorll horizontally...! so that I cant see the content of the table I scrolled.
I want to scroll horizontally to show each uitableViews(by setting some contentOffset) also I want to achieve verticle scrolling of each table individually.
and How to find which table is currently scrolling with multiple UITableViews on UIScrollView ??
any problem with my code ?? how to achieve this ??
Thanks,
Ranganatha
Okay, so the subject talks for itself - I need to change default scrollbar with my custom image. I've been looking for a solution that doesn't require you to write your own ScrollView class or use hacks like creating an UIView with scrollbar image and repositioning it as you scroll.
One solution I liked was to use a simple UIScrollView category and to access scrollbars as UIScrollView's subviews: http://leonov.co/2011/04/uiscrollviews-scrollbars-customization/#comment-7909 For some reason, though, this one doesn't work for me. When I create UIScrollView and get its subviews array only views that I manually add to scrollview are shown there. I cannot access scrollbars iterating through subviews array. For example, this code:
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(10,10,100,100)];
scrollView.userInteractionEnabled = YES;
scrollView.bounces = NO;
scrollView.showsHorizontalScrollIndicator = YES;
NSLog(#"Subviews count is %d", [[scrollView subviews] count]);
will log "Subviews count is 0". Or, if I add X elements to scrollview, "Subviews count is X". Any ideas?
UIScrollbar scroll views are only created when the view is scrolling. They are removed again when the view stops scrolling. That's probably why you can't find them with your category.
You could move your scrollview subview traversing code into the scrollview delegate's scrollViewDidScroll method, which would mean it gets executed whenever the view is scrolling.
I can't help but feel that this is all a horrible and unneccesary hack though, and you'd be better off hiding the scrollbars and implementing them yourself using the delegate methods to determine when to show and hide your custom scrollbar view and the contentOffset property to determine where to position it.
I'd like to have a UITableView with cells wider than 320 points. The user should be able to scroll sideways to be able to view different parts of a UITableViewCell. Is this kind of behavior possible with a UITableView, or should I go and try to implement a tiling UIScrollView?
I tried wrapping a UITableView within a UIScrollView, and the results are terrible - they compete for the scroll gestures and most of the time the scroll view wins, preventing the table from being traversed vertically.
Any input is appreciated!
Thank you!
Update: I tried the proposed solution and it scrolls properly, but the tableview is still only 320 pixels wide. Is tableView's width linked to the window bounds ?
Wrapping the table view with the scroll view is the right way.
UIScrollView with
Show horizontal scrollers
scrolling enabled
autosize to full screen
Inside that, a UITableView
shows vertical scrollers
scrolling enabled
Then I set the table view's frame, with w, being the calculated width of the table view with all columns, whatever your width, and kTableScrollViewHeight being the fixed height of both the table view and the scroll view, in my case, for example 367 points (screen minus status, navbar and tabbar):
tv.frame = CGRectMake(0, 0, w, kTableScrollViewHeight);
and the scroll view's content size
scrollView.contentSize = CGSizeMake(w, kTableScrollViewHeight);
If you want the scroll-to-top behavior when the user taps the status bar, you might want to set
scrollView.scrollsToTop = NO;
because otherwise the scroll view will take away the tap from the table view.
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!!