How to add small red dot in UITabBarItem

Question

How to add red dot on the top right side of the UITabBarItem.

I h

Answer 1

i test this question's answer. but not work on iPad. now i found that, when u add this on iPhone, tabBarItem left and right margin is 2, and each items margin is 4. Code as below:

    NSInteger barItemCount = self.tabBar.items.count;

    UITabBarItem *barItem = (UITabBarItem *)self.tabBar.items[index];
    CGFloat imageHalfWidth = barItem.image.size.width / 2.0;

    CGFloat barItemWidth = (BXS_WINDOW_WIDTH - barItemCount * 4) / barItemCount;
    CGFloat barItemMargin = 4;
    CGFloat redDotXOffset = barItemMargin / 2 + barItemMargin * index + barItemWidth * (index + 0.5);

and iPad as below:

    barItemWidth = 76;
    barItemMargin = 34;
    redDotXOffset = (BXS_WINDOW_WIDTH - 76 * barItemCount - 34 * (barItemCount - 1)) / 2.0 + 76 * (index + 0.5) + 34 * index;

Hope this is useful.

Answer 2

Works both for iPad and iPhone. Be able to hide and calculate index automatically.

Call self.setTabBarDotVisible(visible:true) if self is not an UITabBarController.

Call self.setTabBarDotVisible(visible:true, index:2) if self is an UITabBarController.

import UIKit

public extension UIViewController {

func setTabBarDotVisible(visible:Bool,index: Int? = nil) {

    let tabBarController:UITabBarController!

    if self is UITabBarController
    {
        tabBarController = self as! UITabBarController
    }
    else
    {
        if self.tabBarController == nil
        {
            return
        }
        tabBarController = self.tabBarController!
    }

    let indexFinal:Int

    if (index != nil)
    {
        indexFinal = index!
    }
    else
    {
        let index3 = tabBarController.viewControllers?.index(of: self)

        if index3 == nil
        {
            return;
        }
        else
        {
             indexFinal = index3!
        }

    }

    guard let barItems = tabBarController.tabBar.items else
    {
        return
    }

    //


    let tag = 8888

    var tabBarItemView:UIView?

    for subview in tabBarController.tabBar.subviews {

        let className = String(describing: type(of: subview))

        guard className == "UITabBarButton" else {
            continue
        }

        var label:UILabel?
        var dotView:UIView?

        for subview2 in subview.subviews {

            if subview2.tag == tag {
                dotView = subview2;
            }
            else if (subview2 is UILabel)
            {
                label = subview2 as? UILabel
            }

        }


        if label?.text == barItems[indexFinal].title
        {
            dotView?.removeFromSuperview()
            tabBarItemView = subview;
            break;
        }
    }

    if (tabBarItemView == nil || !visible)
    {
        return
    }



    let barItemWidth = tabBarItemView!.bounds.width

    let x = barItemWidth * 0.5 + (barItems[indexFinal].selectedImage?.size.width ?? barItemWidth) / 2
    let y:CGFloat = 5
    let size:CGFloat = 10;

    let redDot = UIView(frame: CGRect(x: x, y: y, width: size, height: size))

    redDot.tag = tag
    redDot.backgroundColor = UIColor.red
    redDot.layer.cornerRadius = size/2


    tabBarItemView!.addSubview(redDot)
}

}

Answer 3

I have figured out a hack solution.

func addRedDotAtTabBarItemIndex(index: Int,dotRadius: CGFloat) {

    var tabBarButtons = [UIView]()

    // find the UITabBarButton instance.
    for subview in tabBarController!.tabBar.subviews.reverse() {

        if subview.isKindOfClass(NSClassFromString("UITabBarButton")) {

            tabBarButtons.append(subview as! UIView)
        }
    }

    if index >= tabBarButtons.count {
        println("out of bounds")
        return
    }

    let tabBar = tabBarButtons[index]

    var selectedImageWidth: CGFloat!
    var topMargin: CGFloat!

    for subview in tabBar.subviews {

        if subview.isKindOfClass(NSClassFromString("UITabBarSwappableImageView")) {

            selectedImageWidth = (subview as! UIView).frame.size.width
            topMargin = (subview as! UIView).frame.origin.y
        }
    }

    // remove existing red dot.
    for subview in tabBar.subviews {

        if subview.tag == 999 {
            subview.removeFromSuperview()
        }
    }

    let redDot = UIView(frame: CGRect(x: CGRectGetMidX(tabBar.bounds) + selectedImageWidth / 2 + dotRadius, y: topMargin, width: dotRadius * 2, height: dotRadius * 2))

    redDot.backgroundColor = UIColor.redColor()
    redDot.layer.cornerRadius = dotRadius   // half of the view's height.
    redDot.tag = 999

    tabBar.addSubview(redDot)

}

Answer 4

you can try this method:

func addRedDotAtTabBarItemIndex(index: Int) {

    for subview in tabBarController!.tabBar.subviews {

        if let subview = subview as? UIView {

            if subview.tag == 1314 {
                subview.removeFromSuperview()
                break
            }
        }
    }
    let RedDotRadius: CGFloat = 5
    let RedDotDiameter = RedDotRadius * 2

    let TopMargin:CGFloat = 5

    let TabBarItemCount = CGFloat(self.tabBarController!.tabBar.items!.count)

    let HalfItemWidth = CGRectGetWidth(view.bounds) / (TabBarItemCount * 2)

    let  xOffset = HalfItemWidth * CGFloat(index * 2 + 1)

    let imageHalfWidth: CGFloat = (self.tabBarController!.tabBar.items![index] as! UITabBarItem).selectedImage.size.width / 2

    let redDot = UIView(frame: CGRect(x: xOffset + imageHalfWidth, y: TopMargin, width: RedDotDiameter, height: RedDotDiameter))

    redDot.tag = 1314
    redDot.backgroundColor = UIColor.redColor()
    redDot.layer.cornerRadius = RedDotRadius


    self.tabBarController?.tabBar.addSubview(redDot)
}