I have a UIScrollView that shows vertical data, but where the horizontal component is no wider than the screen of the iPhone. The problem is that the user is still able to drag horizontally, and basically expose blank sections of the UI. I have tried setting:
scrollView.alwaysBounceHorizontal = NO;
scrollView.directionalLockEnabled = YES;
Which helps a little, but still doesn't stop the user from being able to drag horizontally. Surely there is a way to fix this easily?
scrollView.bounces = NO;
Worked for me.
That's strange, because whenever I create a scroll view with frame and content size within the bounds of the screen on either dimension, the scroll view does not scroll (or bounce) in that direction.
// Should scroll vertically but not horizontally
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
scrollView.contentSize = CGSizeMake(320, 1000);
Are you sure the frame fits completely within the screen and contentSize's width is not greater than the scroll view's width?
The checkbox for bounce vertically in storyboard-scrollview can simply help...
That works for me in Swift:
scrollView.alwaysBounceHorizontal = false
scrollView.bounces = false
Try setting scrollView.bounces to NO and scrollView.alwaysBounceVertical to YES.
Whether or not a view scrolls (and bounces) horizontally depends on three things:
The content size
The left and right content insets
The width of the scroll view -
If the scroll view can fit the content size plus the insets then it doesn't scroll or bounce.
Avoid horizontal bouncing like so:
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width - scrollView.contentInset.left - scrollView.contentInset.right, height);
I am adding this answer because the previous ones did not take contentInset into account.
Make sure the UIScrollView's contentSize is not wider than the UIScrollView itself. In my own apps this was enough to avoid horizontal scrolling, except in cases where I got really crazy swiping in random directions (e.g., starting a scroll while the view was still decelerating).
If anyone developing for OS X is looking here, as of OS X 10.7, the solution is to set the horizontalScrollElasticity property to false/NO on the scroll view, like this:
Swift:
scrollView.horizontalScrollElasticity = false
Objective-C:
scrollView.horizontalScrollElasticity = NO
Something to keep in mind: You know there's nothing extra to see horizontally, but will your users know that? You may want a little horizontal bounce, even if there's no extra content to show horizontally. This let's the user know that their attempts to scroll horizontally are not being ignored, there's just nothing there for them to see. But, yeah, often you really don't want the bounce.
My version for webViews, a common solution:
- (void)webViewDidFinishLoad:(UIWebView *)webView {
[webView.scrollView setContentSize: CGSizeMake(webView.frame.size.width, webView.scrollView.contentSize.height)];
}
You can disable horizontal bounces like this:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (scrollView.contentOffset.x < 0) {
scrollView.contentOffset = CGPointMake(0, scrollView.contentOffset.y);
} else if (scrollView.contentOffset.x > scrollView.contentSize.width) {
scrollView.contentOffset = CGPointMake(scrollView.contentSize.width, scrollView.contentOffset.y);
}
}
It resets the contentOffset.x manually and won't affect the vertical bounces. It works...
In my case, i just need to set this line:
collectionView.bounces = false
Related
As you can see in the attached image if I keep scrolling past the last object in my scrollview I can keep scrolling and then see the background. Is there a way to limit this in xcode so you can't scroll past the last object in the scroll view?
I'm new to xcode and did try researching this issue though I believe my terminology is impacting this.
Thanks
you will need to set the scrollView.contentSize size so that it fits around all your objects in the scroll view. if you have a way to determine which object is the lowest then you can use its origin + height to determine the height of the content size.
float maxHeight = 0;
for(UIView *v in [scrollView subviews]){
if(v.frame.origin.x + v.frame.size.height > maxHeight)
maxHeight = v.frame.origin.x + v.frame.size.height;
}
self.scrollView.contentSize = CGSizeMake(scrollView.frame.size.width, maxHeight+5);
My UIScrollView is a ~4500px horizontal view that the user needs to scroll horizontally through to view the content.
I have set it up as follows:
- (void)viewDidLoad
{
[super viewDidLoad];
sview.frame = CGRectMake(0, 0, 568, 320);
sview.contentSize = CGSizeMake(4500, 320);
[sview setScrollEnabled:YES];
}
Yet the scroll view does nothing. Is there something obvious I missed? i've tried literally every tutorial on the web.
I got similar issue. I did following modifications and the scrollView started scrolling for me:
Select to check the 'Bounce Horizontally' property for UIScrollView
in xib.
Move the code following code to viewDidAppear instead of
viewDidLoad:
-(void) viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
sview.frame = CGRectMake(0, 0, 568, 320);
sview.contentSize = CGSizeMake(4500, 320);
[sview setScrollEnabled:YES];
}
I think this should help you.
I've explained it here, but there are so many answers to this problem that suggests turning off Auto Layout. That fixes the problem but that's not really the correct solution. Here's my answer:
Turning Auto Layout works, but that's not the solution. If you really need Auto Layout, then use it, if you don't need it, turn it off. But that is not the correct fix for this solution.
UIScrollView works differently with other views in Auto Layout. Here is Apple's release note on Auto Layout, I've copied the interesting bit:
Here are some notes regarding Auto Layout support for UIScrollView:
In general, Auto Layout considers the top, left, bottom, and right edges of a view to be the visible edges. That is, if you pin a view to
the left edge of its superview, you’re really pinning it to the
minimum x-value of the superview’s bounds. Changing the bounds origin
of the superview does not change the position of the view.
The UIScrollView class scrolls its content by changing the origin of its bounds. To make this work with Auto Layout, the top, left, bottom,
and right edges within a scroll view now mean the edges of its content
view.
The constraints on the subviews of the scroll view must result in a size to fill, which is then interpreted as the content size of the
scroll view. (This should not be confused with the
intrinsicContentSize method used for Auto Layout.) To size the scroll
view’s frame with Auto Layout, constraints must either be explicit
regarding the width and height of the scroll view, or the edges of the
scroll view must be tied to views outside of its subtree.
Note that you can make a subview of the scroll view appear to float (not scroll) over the other scrolling content by creating constraints
between the view and a view outside the scroll view’s subtree, such as
the scroll view’s superview.
Apple then goes on to show example of how to correctly use UIScrollView with Auto Layout.
As a general rule, one of the easiest fix is to create a constraint between the element to the bottom of the UIScrollView. So in the element that you want to be at the bottom of the UIScrollView, create this bottom space constraint:
Once again, if you do not want to use Auto Layout, then turn it off. You can then set the contentSize the usual way. But what you should understand is that this is an intended behaviour of Auto Layout.
First of all you have to add some content to UIScrollSiew as subview for scrolling,without content on UIScrollView how can you scroll?. Here is what i did,just add UIImageView to UIScrollView as subview of size same as size of UIScrollView...
In viewDidLoad method try the following code..
-(void)viewDidLoad
{
UIScrollView *scroll=[[UIScrollView alloc] init];
scroll.frame=CGRectMake(0, 0, 320, 460);
UIImageView *imageView=[[UIImageView alloc] init];
imageView.frame=CGRectMake(0, 0, 320,460);
imageView.image=[UIImage imageNamed:#"chiranjeevi.jpeg"];
scroll.contentSize = CGSizeMake(4500, 460);
[scroll setScrollEnabled:YES];
[scroll addSubview:imageView];
[self.view addSubview:scroll];
}
I tested this code it works well.I hope this code will be helpful to you..
I assume you are adding UISrollingView in your Xib file. This will work for you.
sview.delegate = self;
sview.backgroundColor=[UIColor clearColor];
[sview setCanCancelContentTouches:NO];
sview.indicatorStyle = UIScrollViewIndicatorStyleWhite;
sview.clipsToBounds = YES;
sview.scrollEnabled = YES;
sview.contentSize = CGSizeMake(320,570);
CGPoint topOffset = CGPointMake(0,0);
[sview setContentOffset:topOffset animated:YES];
Also, make sure to give IBOutlet connection in your Xib file.
I also faced the same issue.I added the scroll view in xib.I also added some subviews to this scroll view. The scroll view would stop scrolling after I added the subviews. The solution for this problem was in the xib for the view in file inspector Use Autolayout was checked. I unchecked it and the scroll view scrolled after adding the subviews.
The solution was uncheking the Use Autolayout in file inspector in xib.
This should be a pretty common thing to do, but I haven't been able to get it to work exactly right.
I have rectangular content. It normally fits in 320x361: portrait mode minus status bar minus ad minus tab bar.
I have put that content in a UIScrollView and enabled zooming. I also want interface rotation to work. The content will always be a tall rectangle, but when zoomed users might want to see more width at a time and less height.
What do I need to do in Interface Builder and code to get this done? How should I set my autoresizing on the different views? How do I set my contentSize and contentInsets?
I have tried a ton of different ways and nothing works exactly right. In various of my solutions, I've had problems with after some combination of zooming, interface rotation, and maybe scrolling, it's no longer possible to scroll to the entire content on the screen. Before you can see the edge of the content, the scroll view springs you back.
The way I'm doing it now is about 80% right. That is, out of 10 things it should do, it does 8 of them. The two things it does wrong are:
When zoomed in portrait mode, you can scroll past the edge of the content, and see a black background. That's not too much to complain about. At least you can see all the content. In landscape mode, zoomed or not, seeing the black background past the edge is normal, since the content doesn't have enough width to fill the screen at 1:1 zoom level (the minimum).
I am still getting content stuck off the edge when it runs on a test device running iOS 3.0, but it works on mine running 4.x. -- Actually that was with the previous solution. My tester hasn't tried the latest solution.
Here is the solution I'm currently using. To summarize, I have made the scroll view as wide and tall as it needs to be for either orientation, since I've found resizing it either manually or automatically adds complexity and is fragile.
View hierarchy:
view
scrollView
scrollableArea
content
ad
view is 320x411 and has all the autoresizing options on, so conforms to screen shape
scrollView is 480 x 361, starts at origin -80,0, and locks to top only and disables stretching
scrollableArea is 480 x 361 and locks to left and top. Since scrollView disables stretching, the autoresizing masks for its subviews don't matter, but I tell you anyway.
content is 320x361, starts at origin 80,0, and locks to top
I am setting scrollView.contentSize to 480x361.
shouldAutorotateToInterfaceOrientation supports all orientations except portrait upside down.
In didRotateFromInterfaceOrientation, I am setting a bottom content inset of 160 if the orientation is landscape, resetting to 0 if not. I am setting left and right indicator insets of 80 each if the orientation is portrait, resetting if not.
scrollView.minimumZoomScale = 1.0
scrollView.maximumZoomScale = 2.0
viewForZoomingInScrollView returns scrollableArea
// in IB it would be all options activated
scrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
scrollView.contentSize = content.frame.size; // or bounds, try both
what do you mean with scrollableArea?
your minZoomScale is set to 1.0 thats fine for portrait mode but not for landscape. Because in landscape your height is smaller than in portrait you need to have a value smaller than 1.0. For me I use this implementation and call it every time, the frame of the scrollView did change:
- (void)setMaxMinZoomScalesForCurrentBounds {
CGSize boundsSize = self.bounds.size; // self is a UIScrollView here
CGSize contentSize = content.bounds.size;
CGFloat xScale = boundsSize.width / contentSize.width;
CGFloat yScale = boundsSize.height / contentSize.height;
CGFloat minScale = MIN(xScale, yScale);
if (self.zoomScale < minScale) {
[self setZoomScale:minScale animated:NO];
}
if (minScale<self.maximumZoomScale) self.minimumZoomScale = minScale;
//[self setZoomScale:minScale animated:YES];
}
- (void)setFrame:(CGRect)rect { // again, this class is a UIScrollView
[super setFrame:rect];
[self setMaxMinZoomScalesForCurrentBounds];
}
I don't think I understood the entire problem from your post, but here's an answer for what I did understand.
As far as I know (and worked with UIScrollView), the content inside a UIScrollView is not automatically autoresized along with the UIScrollView.
Consider the UIScrollView as a window/portal to another universe where your content is. When autoresizing the UIScrollView, you are only changing the shape/size of the viewing window... not the size of the content in the other universe.
However, if needed you can intercept the rotation event and manually change your content too (with animation so that it looks good).
For a correct autoresize, you should change the contentSize for the scrollView (so that it knows the size of your universe) but also change the size of UIView. I think this is why you were able to scroll and get that black content. Maybe you just updated the contentSize, but now the actuall content views.
Personally, I haven't encountered any case that required to resize the content along with the UIScrollView, but I hope this will get you started in the right direction.
If I understand correctly is that you want a scrollview with an image on it. It needs to be fullscreen to start with and you need to be able to zoom in. On top of that you want it to be able to rotate according to orientation.
Well I've been prototyping with this in the past and if all of the above is correct the following code should work for you.
I left a bit of a white area for the bars/custombars.
- (void)viewDidLoad
{
[super viewDidLoad];
//first inits and allocs
scrollView2 = [[UIScrollView alloc] initWithFrame:self.view.frame];
imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"someImageName"]];
[scrollView2 addSubview:imageView];
[self drawContent]; //refreshing the content
[self.view addSubview:scrollView2];
}
-(void)drawContent
{
//this refreshes the screen to the right sizes and zoomscales.
[scrollView2 setBackgroundColor:[UIColor blackColor]];
[scrollView2 setCanCancelContentTouches:NO];
scrollView2.clipsToBounds = YES;
[scrollView2 setDelegate:self];
scrollView2.indicatorStyle = UIScrollViewIndicatorStyleWhite;
[scrollView2 setContentSize:CGSizeMake(imageView.frame.size.width, imageView.frame.size.height)];
[scrollView2 setScrollEnabled:YES];
float minZoomScale;
float zoomHeight = imageView.frame.size.height / scrollView2.frame.size.height;
float zoomWidth = imageView.frame.size.width / scrollView2.frame.size.width;
if(zoomWidth > zoomHeight)
{
minZoomScale = 1.0 / zoomWidth;
}
else
{
minZoomScale = 1.0 / zoomHeight;
}
[scrollView2 setMinimumZoomScale:minZoomScale];
[scrollView2 setMaximumZoomScale:7.5];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
if (interfaceOrientation == UIInterfaceOrientationPortrait || interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
// Portrait
//the 88pxls is the white area that is left for the navbar etc.
self.scrollView2.frame = CGRectMake(0, 88, [UIScreen mainScreen].bounds.size.width, self.view.frame.size.height - 88);
[self drawContent];
}
else {
// Landscape
//the 88pxls is the white area that is left for the navbar etc.
self.scrollView2.frame = CGRectMake(0, 88, [UIScreen mainScreen].bounds.size.height, self.view.frame.size.width);
[self drawContent];
}
return YES;
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
I hope this will fix your troubles. If not leave a comment.
When you want to put a content (a UIView instance, let's call it theViewInstance ) in a UIScrollView and then scroll / zoom on theViewInstance , the way to do it is :
theViewInstance should be added as the subview of the UIScrollView
set a delegate to the UIScrollView instance and implement the selector to return the view that should be used for zooming / scrolling:
-(UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return theViewInstance;
}
Set the contentSize of the UIScrollView to the frame of the theViewInstance by default:
scrollView.contentSize=theViewInstance.frame.size;
(Additionally, the accepted zoom levels can be set in the UIScrollView :)
scrollView.minimumZoomScale=1.0;
scrollView.maximumZoomScale=3.0;
This is the way a pinch to zoom is achieved on a UIImage : a UIImageView is added to a UIScrollView and in the UIScrollViewDelegate implementation, the UIImageView is returned (as described here for instance).
For the rotation support, this is done in the UIViewController whose UIView contains the UIScrollView we just talked about.
I have the UIScrollView with pagingEnabled set to YES, and programmatically scroll its content to bottom:
CGPoint contentOffset = scrollView.contentOffset;
contentOffset.y = scrollView.contentSize.height - scrollView.frame.size.height;
[scrollView setContentOffset:contentOffset animated:YES];
it scrolls successfully, but after that, on single tap its content scrolls up to offset that it has just before it scrolls down. That happens only when I programmaticaly scroll scrollView's content to bottom and then tap. When I scroll to any other offset and then tap, nothing is happened.
That's definitely not what I'd like to get. How that should be fixed?
Much thanks in advance!
Timur.
This small hack prevents the UIScrollView from scrolling when tapped. Looks like this is happening when the scroll view has paging enabled.
In your UIScrollView delegate add this method:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
scrollView.pagingEnabled = self.scrollView.contentOffset.x < (self.scrollView.contentSize.width - self.scrollView.frame.size.width);
}
This disables the paging when the scroll view reaches the right end in horizontal scrolling (my use case, you can adapt it to other directions easily).
I just figured out what causes this problem, and how to avoid it. If you having pagingEnabled set to YES on a scroll view, you must set the contentOffset to be a multiple of the scroll view's visible size (i.e. you should be on a paging boundary).
Concrete example:
If your scroll view was (say) 460 pixels high with a content area of 920, you would need to set the content offset to EITHER 0 or 460 if you want to avoid the "scroll to beginning on tap" problem.
As a bonus, the end result will probably look better since your scroll view will be aligned with the paging boundaries. :)
The following workaround did help (assume that one extends UIScrollView with a category, so 'self' refers to its instance):
-(BOOL) scrolledToBottom
{
return (self.contentSize.height <= self.frame.size.height) ||
(self.contentOffset.y == self.contentSize.height - self.frame.size.height);
}
Then, one should sometimes turn pagingEnabled off, just at the position where scroll view reaches its bottom. In the delegate (pagingEnabled is initialy on of course, since the problem occurs only when it is enabled):
-(void) scrollViewDidScroll:(UIScrollView *)scrollView
{
if (scrollView.pagingEnabled == YES)
{
if ([scrollView scrolledToBottom] == YES)
scrollView.pagingEnabled = NO;
}
else
{
if ([scrollView scrolledToBottom] == NO)
scrollView.pagingEnabled = YES;
}
}
This seems to be a bug:
UIScrollView doesn't remember the position
I have tested this on iOS 4.2 (Simulator) and the issue remains.
When scrolling a ScrollView I would suggest using
[scrollView scrollRectToVisible:CGRectMake(0,0,1,1) animated:YES];
Where the rect is the position you're after. (In this case the rect would be the top of the scrollview).
Changing the content offset is not the correct way of scrolling a scrollview.
I met a really strange problem while using UITextView, I try to use "GrowStyle" of UITextView, wire up the frame with contentSize, turn off the .scrollEnabled, Build & Run: but when click the bottom of the screen, the keyboard showing up, the UITextView moves up a short distance, and its Top lines disappear, here is the code:
- (void)viewDidLoad {
[super viewDidLoad];
//Turn off the scrollEnabled.
UITextView *growStyleText.scrollEnabled = NO;
//Wire the growStyleText's contentSize to its frame, let it grow.
CGRect selfHack = growStyleText.frame;
selfHack.size = growStyleText.contentSize;
growStyleText.frame = selfHack;
//Make a UIScrollView
UIScrollView *scroll.contentSize = selfHack.size;
scroll.clipsToBounds = NO;
[self.view insertSubview:scroll atIndex:1];
//Add the TextView on the ScrollView, make it scrollable.
[scroll addSubview:growStyleText];
}
After click the last line, Keyboard shows up, then the Top line Disappears! I thought about for all day long, anybody seen this? how can I make Top line moves up instead of disappear? hard question for me, guess there may be simple answers, thank you, very much.
I don't know what you are trying to do, but, since UITextView is a subclass of UIScrollView, why do you need to create it as a subview of a UIScrollView?
Then, in my experience, you can't get the contentSize of a UIScrollView before you add it to a view.
I found this answer very useful
How do I size a UITextView to its content?
Hope it helps.