是否可以自定义UITabBarItem徽章？

Question

以下问题与我的相似。

How to use a custom UIImage as an UITabBarItem Badge?

是否可以使用背景图像而不是自己绘制？我认为这很好，因为我的应用程序只会使用1位数的badgeValue。

如果真的不可能，我想知道我们是否可以改变徽章颜色。以下问题的答案并没有真正帮助。

Is it possible to change UITabBarItem badge color

Answer 1

这是你最好的选择。在文件范围添加此扩展，您可以随意自定义徽章。只需在任何根视图控制器中调用self.tabBarController!.setBadges([1,0,2])即可。

要明确的是，标签栏包含三个项目，徽章值从左到右。

如果要添加图像而只需更改addBadge方法

extension UITabBarController {
    func setBadges(badgeValues:[Int]){

        var labelExistsForIndex = [Bool]()

        for value in badgeValues {
            labelExistsForIndex.append(false)
        }

        for view in self.tabBar.subviews {
            if view.isKindOfClass(PGTabBadge) {
                let badgeView = view as! PGTabBadge
                let index = badgeView.tag

                if badgeValues[index]==0 {
                    badgeView.removeFromSuperview()
                }

                labelExistsForIndex[index]=true
                badgeView.text = String(badgeValues[index])

            }
        }

        for var i=0;i<labelExistsForIndex.count;i++ {
            if labelExistsForIndex[i] == false {
                if badgeValues[i] > 0 {
                    addBadge(i, value: badgeValues[i], color:UIColor(red: 4/255, green: 110/255, blue: 188/255, alpha: 1), font: UIFont(name: "Helvetica-Light", size: 11)!)
                }
            }
        }


    }

    func addBadge(index:Int,value:Int, color:UIColor, font:UIFont){

        let itemPosition = CGFloat(index+1)
        let itemWidth:CGFloat = tabBar.frame.width / CGFloat(tabBar.items!.count)

        let bgColor = color

        let xOffset:CGFloat = 12
        let yOffset:CGFloat = -9

        var badgeView = PGTabBadge()
        badgeView.frame.size=CGSizeMake(17, 17)
        badgeView.center=CGPointMake((itemWidth * itemPosition)-(itemWidth/2)+xOffset, 20+yOffset)
        badgeView.layer.cornerRadius=badgeView.bounds.width/2
        badgeView.clipsToBounds=true
        badgeView.textColor=UIColor.whiteColor()
        badgeView.textAlignment = .Center
        badgeView.font = font
        badgeView.text = String(value)
        badgeView.backgroundColor = bgColor
        badgeView.tag=index
        tabBar.addSubview(badgeView)

    }
}

class PGTabBadge: UILabel {

}

Answer 2

好吧......改变内置徽章的背景对我来说似乎不太可能。但是可能的是以下内容：

对TabBarController进行子类化，构建在NIB中布局的自定义视图，将其添加到选项卡栏中您希望的位置的视图层次结构中。

在自定义视图中，您可以将图像设置为背景，并在该背景上设置标签，该标签将显示您可以按代码更改的数字值。

然后，您需要确定自定义视图的水平和垂直位置，以便将视图放在标签栏中。

希望这有点帮助。塞巴斯蒂安

Answer 3

您可以使用更强大的解决方案@UITabbarItem-CustomBadge。

Demo

简单的两行代码可以帮到你

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

  //supplying the animation parameter
  [UITabBarItem setDefaultAnimationProvider:[[DefaultTabbarBadgeAnimation alloc] init]];
  [UITabBarItem setDefaultConfigurationProvider:[[DefaultSystemLikeBadgeConfiguration alloc] init]];

  //rest of your code goes following...

  return YES;
}

Answer 4

这是另一种基于TimWhiting's answer的解决方案：

extension UITabBar {
        func setBadge(value: String?, at index: Int, withConfiguration configuration: TabBarBadgeConfiguration = TabBarBadgeConfiguration()) {
            let existingBadge = subviews.first { ($0 as? TabBarBadge)?.hasIdentifier(for: index) == true }
            existingBadge?.removeFromSuperview()

            guard let tabBarItems = items,
                let value = value else { return }

            let itemPosition = CGFloat(index + 1)
            let itemWidth = frame.width / CGFloat(tabBarItems.count)
            let itemHeight = frame.height

            let badge = TabBarBadge(for: index)
            badge.frame.size = configuration.size
            badge.center = CGPoint(x: (itemWidth * itemPosition) - (0.5 * itemWidth) + configuration.centerOffset.x,
                                   y: (0.5 * itemHeight) + configuration.centerOffset.y)
            badge.layer.cornerRadius = 0.5 * configuration.size.height
            badge.clipsToBounds = true
            badge.textAlignment = .center
            badge.backgroundColor = configuration.backgroundColor
            badge.font = configuration.font
            badge.textColor = configuration.textColor
            badge.text = value

            addSubview(badge)
        }
    }

    class TabBarBadge: UILabel {
        var identifier: String = String(describing: TabBarBadge.self)

        private func identifier(for index: Int) -> String {
            return "\(String(describing: TabBarBadge.self))-\(index)"
        }

        convenience init(for index: Int) {
            self.init()
            identifier = identifier(for: index)
        }

        func hasIdentifier(for index: Int) -> Bool {
            let has = identifier == identifier(for: index)
            return has
        }
    }

    class TabBarBadgeConfiguration {
        var backgroundColor: UIColor = .red
        var centerOffset: CGPoint = .init(x: 12, y: -9)
        var size: CGSize = .init(width: 17, height: 17)
        var textColor: UIColor = .white
        var font: UIFont! = .systemFont(ofSize: 11) {
            didSet { font = font ?? .systemFont(ofSize: 11) }
        }

        static func construct(_ block: (TabBarBadgeConfiguration) -> Void) -> TabBarBadgeConfiguration {
            let new = TabBarBadgeConfiguration()
            block(new)
            return new
        }
    }

Answer 5

TimWhiting's answer更新到Swift 4，取消了一些力量打开。

extension UITabBarController {
  func setBadges(badgeValues: [Int]) {
    var labelExistsForIndex = [Bool]()

    for _ in badgeValues {
      labelExistsForIndex.append(false)
    }

    for view in tabBar.subviews {
      if let badgeView = view as? PGTabBadge {
        let index = badgeView.tag

        if badgeValues[index] == 0 {
          badgeView.removeFromSuperview()
        }

        labelExistsForIndex[index] = true
        badgeView.text = String(badgeValues[index])
      }
    }

    for i in 0 ... labelExistsForIndex.count - 1 where !labelExistsForIndex[i] && badgeValues[i] > 0 {
      addBadge(
        index: i,
        value: badgeValues[i],
        color: UIColor(red: 4 / 255, green: 110 / 255, blue: 188 / 255, alpha: 1),
        font: UIFont(name: "Helvetica-Light", size: 11)!
      )
    }
  }

  func addBadge(index: Int, value: Int, color: UIColor, font: UIFont) {
    guard let tabBarItems = tabBar.items else { return }
    let itemPosition = CGFloat(index + 1)
    let itemWidth: CGFloat = tabBar.frame.width / CGFloat(tabBarItems.count)

    let bgColor = color

    let xOffset: CGFloat = 12
    let yOffset: CGFloat = -9

    let badgeView = PGTabBadge()
    badgeView.frame.size = CGSize(width: 17, height: 17)
    badgeView.center = CGPoint(x: (itemWidth * itemPosition) - (itemWidth / 2) + xOffset, y: 20 + yOffset)
    badgeView.layer.cornerRadius = badgeView.bounds.width / 2
    badgeView.clipsToBounds = true
    badgeView.textColor = UIColor.white
    badgeView.textAlignment = .center
    badgeView.font = font
    badgeView.text = String(value)
    badgeView.backgroundColor = bgColor
    badgeView.tag = index
    tabBar.addSubview(badgeView)
  }
}

class PGTabBadge: UILabel {}

示例图像