Is there a way that I can use those paging dots independently in my app,
add them to my UIView/NIB and call the functions on it to set total number of dots or current page/dot.
Basically I've UIViewImage in a nib file, i'm displaying images (names taken off an array) on swipe gestures and want to show those paging dots on the bottom for the navigation information.
UIPageControl has it's total page & current page/dot just as you described, let's say pageControl is a instance of UIPageControl, then you can initiate the numberOfPages & currentPage as below:
pageControl.numberOfPages = [images count];
pageControl.currentPage = 0;
Also, you can add action for it when the pageControl's dots was tapped. changePage: method here is just a example:
[pageControl addTarget:self action:#selector(changePage:) forControlEvents:UIControlEventValueChanged];
You can add your images to a UIScrollView and use its delegate method: scrollViewDidScroll::
- (void)scrollViewDidScroll:(UIScrollView *)sender {
// Update the page number
CGFloat pageWidth = scrollView.frame.size.width;
pageControl.currentPage = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
}
It'll change the pageControl's current dot when your swiped to a new image.
Related
I have a scrollView which is a UIScrollView in a CustomCell which is a subclass of UITableViewCell. I have two different pages in a cell. So, I'm using my scrollView in pagingEnabledmode.
My question is that can i change my scrollView background color after passing second page then set it back to initial color after returning back ?
So far, i tried to use two different UIScrollView, then i realized that i can't use pagingEnabled mode.
To be more specific, i want my initial screen which width is 360 and height is 70 in blue,and my second screen is green which starts after 360 px.
Try to use the scrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)sender {
CGFloat pageWidth = 360;
int page = floor(scroll.contentOffset.x / pageWidth) ;
if (page == 1) { /// second scroll page
myView.backgroundColor = [UIColor greenColor];
} else { ///first scroll page
myView.backgroundColor = [UIColor blueColor];
}
}
try this one :
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
int page = scrollView.contentOffset.x / scrollView.frame.size.width;
if (page == 0){
// first page's background color
}
else{
// first page's background color
}
}
Also in the viewDidLoad add this :
mainScroll.ContentSize = CGSizeMake(320*2, 70);
I'm a beginner when it comes to page control, and that's why I'm not sure 100% if my title agrees with what I want. I want to make a UIPageControl that when the user swipes on the screen, the view would switch over to another view and the UIPageController at the bottom of the screen would update itself. Also, to make my request even more confusing, I want a tab bar at the bottom of the screen that would stay put as the views change.
A great example of this is The Iconfactory's Ramp Champ:
http://img.slidetoplay.com/screenshots/ramp-champ_5.jpg
The bar at the bottom stays put while the rest of the items on the screen moves. What would be the easiest way to do this?
EDIT: I know I have to use a UISrollView, I just don't know how to go about implementing it...
I believe what you're looking for is actually a UIScrollView with pagingEnabled set to YES. You can leave the scrollview as a view above a regular UITabBar. You'll use a UIPageControl to get the little dots. You can update it programmatically when the UIScrollView scrolls to a page by implementing an appropriate delegate method of the scroll view, maybe -scrollViewDidScroll:.
Assume you have two ivars: scrollView and pageControl. When you know how many pages your scroll view will have, you can set the contentSize of scrollView. It should be a multiple of the scrollView's bounds. For example, if the number of pages is static you can hardcode it in your -viewDidLoad...
- (void)viewDidLoad {
// Any other code.
scrollView.pagingEnabled = YES;
scrollView.contentSize = CGSizeMake(scrollView.bounds.size.width * 3, scrollView.bounds.size.height); // 3 pages wide.
scrollView.delegate = self;
}
Then, to update your little dots...
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGFloat pageWidth = scrollView.bounds.size.width;
NSInteger pageNumber = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
pageControl.currentPage = pageNumber;
}
You need to use a UIScrollView
Assuming you have a named ivar called scrollView
int amountOfFrames = 10;
scrollView.pagingEnabled = TRUE;
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * amountOfFrames, scrollView.frame.size.height);
scrollView.delegate = self;
You will then need to implement the required delegate methods, so that you can update your page control
- (void)scrollViewDidScroll:(UIScrollView *)sender
{
// Switch the indicator when more than 50% of the previous/next page is visible
CGFloat pageWidth = scrollView.frame.size.width;
int page = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
pageControl.currentPage = page;
}
You need to place whatever content you want to be scrollable inside these scrollview, ideally lazyload into it, if the content you will displaying will require a lot of heap memory, use the scrollviewDidScroll to remove and add content at the required positions
How do I navigate to a specific page programmatically. Basically I have an app with a scrollView populated with a bunch of subviews (tableViews in this case). When clicking on a subview it zooms in and the user can edit and navigate the table, however when I zoom back out I reload the entire view in case there were any changed made by the user. Of course reloading the view sends the user back to page 0. I've tried setting the pageControl.currentpage property but all that does is change the dot of the pageControl. Does that mean that something is wrong or do I need to do something else as well??
All that is controlling the page scrolling is this method:
- (void)scrollViewDidScroll:(UIScrollView *)sender
{
CGFloat pageWidth = self.scrollView.frame.size.width;
int page = floor((self.scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
self.pageControl.currentPage = page;
NSString *listName = [self.wishLists objectAtIndex:self.pageControl.currentPage];
self.labelListName.text = listName;
}
You have to calculate the corresponding scroll position manually. To scroll to page i:
[scrollView setContentOffset:CGPointMake(scrollView.frame.size.width*i, 0.0f) animated:YES];
Swift 5 you can easily use scrollView.scrollRectToVisible
If the Horizontal paging scroll view implemented, which has the size of default view width of the device and wanted to navigate to number n page:
scrollView.scrollRectToVisible(CGRect(x: self.view.center.x * n, y: self.view.center.y, width: self.view.frame.width, height: self.view.frame.height) ,animated: true)
You just have to define the CGRect() position according to your scrollview configurations.
Swift 5 version of above answer by Ole Begemann
scrollView.setContentOffset( CGPoint(x: scrollView.frame.size.width * i, y: 0.0), animated: true)
This may be a simple problem. I have a UIScrollView with 3 views. I need to display 3 dots like Indicator ( to indicate there are more pages to the user). How do i do this?
use a UIPageControl:
pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(...)]; // set in header
[pageControl setNumberOfPages:3];
[pageControl setCurrentPage:0];
[pageControl setBackgroundColor:[UIColor clearColor]];
[self.view addSubview:pageControl];
That is the UI component that shows the dots... the number of pages is the number of dots. The current page is the one that is currently highlighted.
Then you need to use the scroll view delegate method to determine what page you've scrolled to:
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
int newOffset = scrollView.contentOffset.x;
int newPage = (int)(newOffset/(scrollView.frame.size.width));
[pageControl setCurrentPage:newPage];
}
You could create contentView in which you add UIScrollView and UIPageControl, set numberOfPages of pageControl to selected count and when you scroll you change page in your pageControl ( currentPage property ).
Cheers,
Krzysztof Zabłocki
You can use a UIPageControl with 3 dots on it. You'll need screen space (assuming the bottom of the screen) to put the page control so your scrollview won't be able to be full height.
If I've got a uiscrollview which is five pages wide, what code would tell me what page I am on, when I scroll to a new page? Also, what code would scroll to a specific page?
Thanks!
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
CGFloat pageWidth = scrollView.frame.size.width;
int currentPage = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
pageControl.currentPage = currentPage;
}
I have the scrollview frame width as the page width. If you are using something else as page width, make respective changes to get this to work
for scrolling to current page - if I understand it right, you have an option to enter page number and choose to scroll to that page:
Just the code above, do it reverse order, and solve for contentOffset.X
once you have the x value, create a frame with that x in it, and scrollToRect: animated: will do the work.
Check out the PageControl example from Apple:
http://developer.apple.com/iphone/library/samplecode/PageControl/Listings/ReadMe_txt.html
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
CGFloat scroller_x = [scrollView contentOffset].x;
CGFloat scroller_y = [scrollView contentOffset].y;
NSLog(#"%f, %f",scroller_x,scroller_y);
}
Once this delegate method fires (on scroll) check it against each views frame.origin.x and frame.origin.y The view's frame that matches will be the view that you scrolled to.
[scrollView setContentOffset:<#(CGPoint)#>];
use this method to scroll to a specific view.frame.origin. So suppose you have an action to go to a specific view, you can use [scrollView setContentOffset:view.frame.origin] to get there.
(assumed paging is enabled)