How to add multiple UIImageViews to paging UIScrollView? - ios

Question

I have a UIScrollView with paging enabled with multiple subviews on the page: a UIButton, UIwebview and UIImageView. Both the webview and the image change on every page. This works fine. I used Apples scrolling image paging example to get me started.
But when I add a second UIImageView, the position of image I have in place already gets the new values and the new image doesn't display.
This is the code inside viewdidload for the first image (works fine):
// load all the images from our bundle and add them to the scroll view
for (i = 1; i <= kNumImages; i++)
{
NSString *imageName = [NSString stringWithFormat:#"image%d.jpg", i];
UIImage *image2 = [UIImage imageNamed:imageName];
UIImageView *imageView2 = [[UIImageView alloc] initWithImage:image2];
// setup each frame to a default height and width, it will be properly placed when we call "updateScrollList"
CGRect rect = imageView2.frame;
rect.size.height = imageviewScrollObjHeight;
rect.size.width = imageviewScrollObjWidth;
// Get the Layer of any view
CALayer * imageLayer = [imageView2 layer];
[imageLayer setMasksToBounds:YES];
[imageLayer setCornerRadius:7.0];
// You can even add a border
[imageLayer setBorderWidth:1.0];
[imageLayer setBorderColor:[[UIColor lightGrayColor] CGColor]];
imageView2.frame = rect;
imageView2.tag = i; // tag our images for later use when we place them in serial fashion
[scrollView1 addSubview:imageView2];
}
[self layoutScrollImages]; // now place the photos in serial layout within the scrollview
This is the code to layout the first image on every page, different image per page(outside viewdidload)(works fine):
// layout images for imageview1
- (void)layoutScrollImages
{
UIImageView *imageView = nil;
NSArray *subviews = [scrollView1 subviews];
// reposition all image subviews in a horizontal serial fashion
CGFloat curXLoc = 10;
for (imageView in subviews)
{
if ([imageView isKindOfClass:[UIImageView class]] && imageView.tag > 0)
{
CGRect frame = imageView.frame;
frame.origin = CGPointMake(curXLoc, 50);
imageView.frame = frame;
curXLoc += (kScrollObjWidth);
}
}
// set the content size so it can be scrollable
[scrollView1 setContentSize:CGSizeMake((kNumImages * kScrollObjWidth), [scrollView1 bounds].size.height)];
}
This is the code for the second image (inside viewdidload): (when i remove [self layoutNavScrollImages]; the image loads only on the first page)
for (i = 1; i <= kNumImages; i++)
{
UIImage *navBarImage = [UIImage imageNamed:#"navigationbar.png"];
UIImageView *imageViewNavBar = [[UIImageView alloc] initWithImage:navBarImage];
// setup each frame to a default height and width, it will be properly placed when we call "updateScrollList"
CGRect navBarRect = imageViewNavBar.frame;
navBarRect.size.height = 44;
navBarRect.size.width = 320;
navBarRect.origin.x = 0;
navBarRect.origin.y = 0;
/* Get the Layer of any view
CALayer * imageLayer = [imageView3 layer];
[imageLayer setMasksToBounds:YES];
[imageLayer setCornerRadius:7.0];
// You can even add a border
[imageLayer setBorderWidth:1.0];
[imageLayer setBorderColor:[[UIColor lightGrayColor] CGColor]];
*/
imageViewNavBar.frame = navBarRect;
imageViewNavBar.tag = i; // tag our images for later use when we place them in serial fashion
[scrollView1 addSubview:imageViewNavBar];
}
[self layoutNavScrollImages];
And the code outside viewdidload:(this overwrites the position of the first image)
- (void)layoutNavScrollImages
{
UIImageView *view = nil;
NSArray *subviews = [scrollView1 subviews];
// reposition all image subviews in a horizontal serial fashion
CGFloat curXLoc = 0;
for (view in subviews)
{
if ([view isKindOfClass:[UIImageView class]] && view.tag > 0)
{
CGRect frame = view.frame;
frame.origin = CGPointMake(curXLoc, 0);
view.frame = frame;
curXLoc += (kScrollObjWidth);
}
}
// set the content size so it can be scrollable
[scrollView1 setContentSize:CGSizeMake((kNumImages * kScrollObjWidth), [scrollView1 bounds].size.height)];
}

Answer 1

The way to do this is to make one (big) UIView and add every UIImageView as a subview of that UIView. And then add the UIView as a subview to UIScrollView.
[totalView addSubview:imageView1];
[totalView addSubview:imageView2;
[totalView addSubview:buttonView1];
[totalView addSubview:buttonView2];
[totalView addSubview:webView];
[scrollView addSubview:totalView];
Be sure to set the right content size or scrollview wont work:
[scrollView setContentSize:CGSizeMake((320*kNumImages), 411)];
Setup views and tag the UIView (inside viewdidload):
NSUInteger i;
for (i = 1; i <= kNumImages; i++)
{
//... code to setup views
totalView.tag = i;
}
[self layoutViews]; // now place the views in serial layout within the scrollview
Then to layout the view on every page:
- (void)layoutViews
{
UIView *view = nil;
NSArray *subviews = [scrollView subviews];
// reposition all image subviews in a horizontal serial fashion
CGFloat curXLoc = 0;
for (view in subviews)
{
if ([view isKindOfClass:[UIView class]] && view.tag > 0)
{
CGRect frame = view.frame;
frame.origin = CGPointMake(curXLoc, 0);
view.frame = frame;
curXLoc += (kScrollObjWidth);
}
}
}
I hope this is as clear as possible. If anyone thinks this is not the right way to do it please comment.