Customise Position of UIPageControl

Question

I am using project from github as a reference.

project URL:

https://github.com/lephuocdai/iOSsample/tree/master/PageViewDemo

In this project i want to show the UIPageControl at top left position .

I tried setting the rect property of pageControl using CGRectMake() to some value ;But it shows always at bottom center

Answer 1

here s a very neat and 100% effective way to get to change the position of the pageControl

extension UIPageViewController {
  override open func viewDidLayoutSubviews() {
      super.viewDidLayoutSubviews()

      for subV in self.view.subviews {
          if type(of: subV).description() == "UIPageControl" {
              let pos = CGPoint(x: newX, y: newY)
              subV.frame = CGRect(origin: pos, size: subV.frame.size)
          }
      }
  }
}

Answer 2

The project uses a UIPageViewController to handle the display and movement through the content. You can supply data to that object so it displays a UIPageControl as you say. BUT you have no control over the display of that item, other than maybe some colour styling. If you want to position it, you'll need to implement you're own instance of UIPageControl and handle it's content, position and changes manually.

Answer 3

Override the viewDidLayoutSubviews() of the pageviewcontroller and use this

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    // get pageControl and scroll view from view's subviews
    let pageControl = view.subviews.filter{ $0 is UIPageControl }.first! as! UIPageControl
    let scrollView = view.subviews.filter{ $0 is UIScrollView }.first! as! UIScrollView
    // remove all constraint from view that are tied to pagecontrol
    let const = view.constraints.filter { $0.firstItem as? NSObject == pageControl || $0.secondItem as? NSObject == pageControl }
    view.removeConstraints(const)

    // customize pagecontroll
    pageControl.translatesAutoresizingMaskIntoConstraints = false
    pageControl.addConstraint(pageControl.heightAnchor.constraintEqualToConstant(35))
    pageControl.backgroundColor = view.backgroundColor

    // create constraints for pagecontrol
    let leading = pageControl.leadingAnchor.constraintEqualToAnchor(view.leadingAnchor)
    let trailing = pageControl.trailingAnchor.constraintEqualToAnchor(view.trailingAnchor)
    let bottom = pageControl.bottomAnchor.constraintEqualToAnchor(scrollView.topAnchor, constant:8) // add to scrollview not view

    // pagecontrol constraint to view
    view.addConstraints([leading, trailing, bottom])
    view.bounds.origin.y -= pageControl.bounds.maxY
}

Answer 4

is your page control encompassed within some other View, if so then you may be setting the co-ordinates wrong, try to put log of your page control.frame so as to know where it lies

Answer 5

If using storyboards, place a UIPageControl object using the menu in the bottom right and set constraints.

If using frames, just programmatically add it:

var pageControl = UIPageControl()
pageControl.frame = CGRectMake(0,0,0,0) <- These are the coordinates.
self.view.addSubView(pageControl)

Answer 6

if you set the frame for UIPageControl , it doesnot work. Other than this you can set the transform.

[_pageControl setTransform:CGAffineTransformMakeTranslation(100, 0.0)];

enjoy coding