iOS - UIScrollView is not working (it doesn't

问题:

I would like to display an image (width: 320 pixels, height: 1250 pixels) in an image view.

When I compile the application I get no scrolling at all. The view stays fixed.

What I did:

1. Added an UIScrollView via Interface Builder to my view.
2. Added an UIImageView via Interface Builder to my view.
3. Verified that UIImageView is below UIScrollView in Interface Builder.
4. Set the size of the UIScrollView with ViewDidLoad.

How do I do this?

Code:

- (void)viewDidLoad
{
    [super viewDidLoad];
    scrollView.contentSize = CGSizeMake(320, 1250);
}

Screenshots:

ImageView:

ScrollView:

回答1:

I just have done the same task.. Try this one.....

scrollView.delegate = self;
scrollView.scrollEnabled = YES;

int scrollWidth = 120;
scrollView.contentSize = CGSizeMake(scrollWidth,80);     


int xOffset = 0;
imageView.image = [UIImage imageNamed:[imagesName objectAtIndex:0]];

for(int index=0; index < [imagesName count]; index++)
{       
    UIImageView *img = [[UIImageView alloc] init];
    img.bounds = CGRectMake(10, 10, 50, 50);
    img.frame = CGRectMake(5+xOffset, 0, 50, 50);
    NSLog(@"image: %@",[imagesName objectAtIndex:index]);
    img.image = [UIImage imageNamed:[imagesName objectAtIndex:index]];
    [images insertObject:img atIndex:index];         
    scrollView.contentSize = CGSizeMake(scrollWidth+xOffset,110); 
    [scrollView addSubview:[images objectAtIndex:index]];

    xOffset += 70;
}

Also set this one....

imagesName = [[NSArray alloc]initWithObjects:@"image1.jpg",@"image2.jpg",@"image3.jpg",@"image4.jpg",@"image5.jpg",@"image6.png",@"image7.png",@"image9.png",nil];
    images = [[NSMutableArray alloc]init];

回答2:

So for me the problem was that setting the content size didn't work in viewDidLoad(). I tried everything and I didn't understand why it wouldn't want to work, and then I tried the same stuff in viewDidAppear() and it magically worked...

回答3:

From you last screenshot and from your comments it looks like your scrollView is way to big. The scrollview must be visible on screen completely. For example a full screen UIScrollView on iPhone would have a size of 320 x 460.

If the scrollview is the same size as its content you can't scroll.

The greenish rectangle shows the size of your scrollview, the pinkish the size of your content (your image):

回答4:

I came across this same issue on iOS6 and the solution was to programmatically adjust the ContentSize. So I will just quote from Raja (above) to show this:

CGSize scrollViewContentSize = CGSizeMake(320, 400);
[self.scrollView setContentSize:scrollViewContentSize];

NOTE: I was not having this issue on iOS5.. seems like iOS6 decided to do alot of prank just like the rotation/orientation saga

回答5:

Since Xcode 5 it does not work like before. Also scrolling to the end of a scrollable text field makes problems. There are also differences between doing it on iPhone or iPad. On iPhone it worked without delayed timer.

This worked for me:

- (void)viewDidLoad
{
    [super viewDidLoad];
    NSTimer *timerforScrollView;
    timerforScrollView =[NSTimer scheduledTimerWithTimeInterval:0.1
           target:self selector:@selector(forScrollView)userInfo:nil repeats:NO];   
}

- (void) forScrollView {
    [scrollviewPad setScrollEnabled:YES];
    [scrollviewPad setContentSize:CGSizeMake(768, 1015)]; // must be greater then the size in Storyboard
}

回答6:

I found I had a similar problem but none of the above code worked. The issue was due to autolayout. I found that if I turned off autolayout by going to the storyboard clicking on Utilities -> File Inspector and unchecked Use Autolayout the scrolling did work (I also set scroll.contentSize = ...).

回答7:

Swift 4, iOS 11

The simplest way using autolayout:

1. Add UIScrollView and pin it 0,0,0,0 to superview (or your desired size)
2. Add UIView in ScrollView, pin it 0,0,0,0 to all 4 sides and center it horizontally and vertically.
3. In size inspector, change 'bottom' and 'align center Y' priority to 250.
4. Add all views that you need into this view. Don't forget to set the bottom constraint on the lowest view.

回答8:

Sometimes autoLayout checkbox is ticked in the xib. That also creates this issue in xcode 5. Which makes the UIScrollView scrolling off.

回答9:

Don't forget to add the category protocol to the interface, like this

@interface MyViewController : <UIScrollViewDelegate>

If you don't, you will not be able to set the scroll view delegate to self

(i.e. [MyScrollView setDelegate:self];)

If you do this, it should work.

My code is:

-(void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];

    [contentScrollView setDelegate:self];
    [contentScrollView setScrollEnabled:YES];
    contentScrollView.contentSize = CGSizeMake(310, 500);
    contentScrollView.frame = CGRectMake(5, 188, 310, 193);
}

回答10:

Did you assign the scroll's view delegate? Always remember these:

[self.scrollView setDelegate:self]; 
[self.scrollView setScrollEnabled:YES];

回答11:

The image view has to be a subview (so inside AND below) of the scrollview. From your description it seems they are paralell

回答12:

You forgot one line. Add this to your view load function:

[scrollView setScrollEnabled:YES];

回答13:

You could try disabling AutoLayout. In XCode 5 I tested all the above answers and I could only scroll it by disabling autolayout and activating all autosizing masks under the Size Inspector. The following code was used too:

self.scrollView.contentSize = CGSizeMake(320, 900);
self.scrollView.delegate = self;
self.scrollView.scrollEnabled = YES;
self.scrollView.frame = self.view.frame;

回答14:

CGRect scrollViewFrame = CGRectMake(0, 0, 320, 400);
self.scrollView = [[UIScrollView alloc] initWithFrame:scrollViewFrame];

[self.view addSubview:self.scrollView];
CGSize scrollViewContentSize = CGSizeMake(320, 400);
[self.scrollView setContentSize:scrollViewContentSize];
scrollView.delegate = self;

[self.scrollView setBackgroundColor:[UIColor blackColor]];
[scrollView setCanCancelContentTouches:NO];

scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
scrollView.clipsToBounds = YES;
scrollView.scrollEnabled = YES;
scrollView.pagingEnabled = YES;

NSUInteger nimages = 0;
CGFloat cx = 0;
for (; ; nimages++) {
    NSString *imageName = [NSString stringWithFormat:@"image%d.jpg", (nimages + 1)];
    UIImage *image = [UIImage imageNamed:imageName];
    if (image == nil) {
        break;
    }
    UIImageView *imageView = [[UIImageView alloc] initWithImage:image];

    CGRect rect = imageView.frame;
    rect.size.height = image.size.height;
    rect.size.width = image.size.width;
    rect.origin.x = ((scrollView.frame.size.width - image.size.width) / 2) + cx;
    rect.origin.y = ((scrollView.frame.size.height - image.size.height) / 2);

    imageView.frame = rect;

    [scrollView addSubview:imageView];
    [imageView release];

    cx += scrollView.frame.size.width;
}


[scrollView setContentSize:CGSizeMake(cx, [scrollView bounds].size.height)];

回答15:

Assuming that scrollView is a subview of view and fills it entirely you can use the following in viewDidLoad:

  [scrollView setContentSize: CGSizeMake(self.view.frame.size.width, self.view.frame.size.height)];

I had a UIScrollView that was not scrolling and this allowed it to scroll.

回答16:

Just add code

scrollView.contentSize = CGSizeMake(WIDTH,HEIGHT);

to method -(void)viewDidLayoutSubviews. For more information checkout Stanford CS193p Lecture No 8 to understand View Controller Life cycle.

回答17:

I had the same issue and was looking for the answer in this thread. I tried all the stuff, but nothing works. Then I found this:

.

You just need to deselect "Use Auto Layout" in File Inspector of your ViewController. Ta-Da, it works immediately for me. Enjoy.