Swift：带有中心圆形按钮的自定义 TabBar

Question

我尝试创建自定义标签栏，如下图所示：

以下是我得到的结果：

以下是我当前的代码：

class CustomTabBarController: UITabBarController {


    override func viewDidLoad() {
        super.viewDidLoad()

        let controller1 = UIViewController()
        controller1.tabBarItem = UITabBarItem(tabBarSystemItem: .contacts, tag: 1)
        let nav1 = UINavigationController(rootViewController: controller1)

        let controller2 = UIViewController()
        controller2.tabBarItem = UITabBarItem(tabBarSystemItem: .contacts, tag: 2)
        let nav2 = UINavigationController(rootViewController: controller2)

        let controller3 = UIViewController()
        let nav3 = UINavigationController(rootViewController: controller3)
        nav3.title = ""

        let controller4 = UIViewController()
        controller4.tabBarItem = UITabBarItem(tabBarSystemItem: .contacts, tag: 4)
        let nav4 = UINavigationController(rootViewController: controller4)

        let controller5 = UIViewController()
        controller5.tabBarItem = UITabBarItem(tabBarSystemItem: .contacts, tag: 5)
        let nav5 = UINavigationController(rootViewController: controller5)

        viewControllers = [nav1, nav2, nav3, nav4, nav5]
        setupMiddleButton()  
    }

    func setupMiddleButton() {
        let menuButton = UIButton(frame: CGRect(x: 0, y: 0, width: 64, height: 64))
        var menuButtonFrame = menuButton.frame
        menuButtonFrame.origin.y = view.bounds.height - menuButtonFrame.height - 50
        menuButtonFrame.origin.x = view.bounds.width/2 - menuButtonFrame.size.width/2
        menuButton.frame = menuButtonFrame

        menuButton.backgroundColor = UIColor.red
        menuButton.layer.cornerRadius = menuButtonFrame.height/2
        view.addSubview(menuButton)

        menuButton.setImage(UIImage(named: "example"), for: .normal)
        menuButton.addTarget(self, action: #selector(menuButtonAction(sender:)), for: .touchUpInside)

        view.layoutIfNeeded()
    }


    // MARK: - Actions

    @objc private func menuButtonAction(sender: UIButton) {
        selectedIndex = 2
    }

}

如何绘制第一张图片关节的tabbar的形状

我被困住了，非常感谢您的帮助

Answer 1

你需要自定义你的CustomTabBarController的标签栏

只需将 AppTabBar 分配给 tabBarController 的标签栏，就可以像这样 它应该可以工作

@IBDesignable
class AppTabBar: UITabBar {

    private var shapeLayer: CALayer?

    override func draw(_ rect: CGRect) {
        self.addShape()
    }

    private func addShape() {
        let shapeLayer = CAShapeLayer()
        shapeLayer.path = createPath()
        shapeLayer.strokeColor = UIColor.lightGray.cgColor
        shapeLayer.fillColor = #colorLiteral(red: 0.9782002568, green: 0.9782230258, blue: 0.9782107472, alpha: 1)
        shapeLayer.lineWidth = 0.5
        shapeLayer.shadowOffset = CGSize(width:0, height:0)
        shapeLayer.shadowRadius = 10
        shapeLayer.shadowColor = UIColor.gray.cgColor
        shapeLayer.shadowOpacity = 0.3

        if let oldShapeLayer = self.shapeLayer {
            self.layer.replaceSublayer(oldShapeLayer, with: shapeLayer)
        } else {
            self.layer.insertSublayer(shapeLayer, at: 0)
        }
        self.shapeLayer = shapeLayer
    }

    func createPath() -> CGPath {
        let height: CGFloat = 86.0
        let path = UIBezierPath()
        let centerWidth = self.frame.width / 2
        path.move(to: CGPoint(x: 0, y: 0))
        path.addLine(to: CGPoint(x: (centerWidth - height ), y: 0))
        path.addCurve(to: CGPoint(x: centerWidth, y: height - 40),
                      controlPoint1: CGPoint(x: (centerWidth - 30), y: 0), controlPoint2: CGPoint(x: centerWidth - 35, y: height - 40))
        path.addCurve(to: CGPoint(x: (centerWidth + height ), y: 0),
                      controlPoint1: CGPoint(x: centerWidth + 35, y: height - 40), controlPoint2: CGPoint(x: (centerWidth + 30), y: 0))
        path.addLine(to: CGPoint(x: self.frame.width, y: 0))
        path.addLine(to: CGPoint(x: self.frame.width, y: self.frame.height))
        path.addLine(to: CGPoint(x: 0, y: self.frame.height))
        path.close()
        return path.cgPath
    }

    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        guard !clipsToBounds && !isHidden && alpha > 0 else { return nil }
        for member in subviews.reversed() {
            let subPoint = member.convert(point, from: self)
            guard let result = member.hitTest(subPoint, with: event) else { continue }
            return result
        }
        return nil
    }
}

extension UITabBar {
    override open func sizeThatFits(_ size: CGSize) -> CGSize {
        var sizeThatFits = super.sizeThatFits(size)
        sizeThatFits.height = 74
        return sizeThatFits
    }
}