UIPageViewController page control background color

问题

i'm using UIPageViewController in my app and it's working fine. however, it's page control which has been added automatically has a black background which is hiding the current view controller's bottom material (See picture below). is it possible to call the UIPageViewController's page control and change it's color? i want the page control to be shown over the view controller (example, the Path app's walkthrough) like setting the color instead of black to clear.

回答1:

You can use appearance to change the color of UIPageControl as otherwise it is not accessible. Try doing it in your AppDelegate's didFinishLaunchingWithOptions function as given below.

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    UIPageControl *pageControl = [UIPageControl appearance];
    pageControl.pageIndicatorTintColor = [UIColor lightGrayColor];
    pageControl.currentPageIndicatorTintColor = [UIColor blackColor];
    pageControl.backgroundColor = [UIColor blueColor];

    return YES;
}

To apply style only to a particular view controller, you can use appearanceWhenContainedIn instead as following:

UIPageControl *pageControl = [UIPageControl appearanceWhenContainedIn:[MyViewController class], nil];

Only UIPageControl objects contained in the MyViewController are going to get this style.

EDIT: The black background around UIPageControl at the bottom of your screen is due to the background color of your UIPageViewController not UIPageControl. You can change this color as following:

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor blueColor]; //Set it to whatever you like
}

回答2:

Updated for Swift 3:

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    for view in self.view.subviews {
        if view is UIScrollView {
            view.frame = UIScreen.main.bounds
        } else if view is UIPageControl {
            view.backgroundColor = UIColor.clear
        }
    }
}

Swift 2 example for anyone that needs it. Put this inside your UIPageController subclass.

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    for view in self.view.subviews {
        if view is UIScrollView {
            view.frame = UIScreen.mainScreen().bounds
        } else if view is UIPageControl {
            view.backgroundColor = UIColor.clearColor()
        }
    }
}

回答3:

Add the following code in the UIPageViewController.

- (void)viewDidLoad {
    [super viewDidLoad];
    [[UIPageControl appearance] setPageIndicatorTintColor: [UIColor grayColor]];
    [[UIPageControl appearance] setCurrentPageIndicatorTintColor: [UIColor whiteColor]];
    [[UIPageControl appearance] setBackgroundColor: [UIColor darkGrayColor]];
}

回答4:

Just subclass UIPageViewController and add this code:

- (void)viewDidLayoutSubviews {
  [super viewDidLayoutSubviews];
  for (UIView *view in self.view.subviews) {
    if ([view isKindOfClass:[NSClassFromString(@"_UIQueuingScrollView") class]]) {
      CGRect frame = view.frame;
      frame.size.height = view.superview.frame.size.height;
      view.frame = frame;
    }
  }
}

This will extend internal scroll view frame.

回答5:

Here is the Swift 2+ version of Yas-T's Answer

//In AppDelegate
let pageControl = UIPageControl.appearance()
pageControl.pageIndicatorTintColor = UIColor.lightGrayColor()
pageControl.currentPageIndicatorTintColor = UIColor.blackColor()
pageControl.backgroundColor = UIColor.blueColor()

//Or in your ViewController (Only available on IOS 9.0)
if #available(iOS 9.0, *) {
   let pageControl = UIPageControl.appearanceWhenContainedInInstancesOfClasses([ViewController.self])
   pageControl.pageIndicatorTintColor = UIColor.lightGrayColor()
   pageControl.currentPageIndicatorTintColor = UIColor.darkGrayColor()
}

回答6:

Override the function viewDidLayoutSubviews() in PageViewController:

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    for view in view.subviews{
        if view is UIScrollView{
            view.frame = UIScreen.main.bounds
        }else if view is UIPageControl{
            view.backgroundColor = UIColor.clear
        }
    }
}

回答7:

Here is the Swift 3+ version of accepted Answer (with a plus of a custom Color created):

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    if #available(iOS 9.0, *) {

        let pageControl = UIPageControl.appearance(whenContainedInInstancesOf: [UIPageViewController.self])
        pageControl.pageIndicatorTintColor = UIColor.init(colorLiteralRed: 43/255.0, green: 170/255.0, blue: 226/255.0, alpha: 0.4)
        pageControl.currentPageIndicatorTintColor = UIColor.init(colorLiteralRed: 43/255.0, green: 170/255.0, blue: 226/255.0, alpha: 1.0)        
    }

    return true
}

回答8:

Well, I found a working solution. Inside your UIPageViewController, just add this code:

-(void)viewDidLayoutSubviews
{
   [super viewDidLayoutSubviews];

   for (UIView *view in self.view.subviews)
   {
       if ([view isKindOfClass:UIScrollView.class])
       {
           CGRect frame      = view.frame;

           frame.size.height = view.superview.frame.size.height;

           view.frame        = frame;
       }

       if ([view isKindOfClass:UIPageControl.class])
       {
           CGFloat newHeight    = 22;

           CGRect frame         = view.frame;

           frame.origin.y      += frame.size.height - newHeight;
           frame.size.height    = newHeight;

           view.frame           = frame;
           view.backgroundColor = UIColor.darkGrayColor;
           view.alpha           = 0.3;
       }
   }

}

来源：https://stackoverflow.com/questions/18408269/uipageviewcontroller-page-control-background-color