ios - 使标签栏上的自定义按钮变圆

Question

这是我正在尝试做的事情:

注:截图取自较早版本的iOS

我所取得的成就:

代码:

 override func viewWillAppear(animated: Bool) {
    // Creates image of the Button
    let imageCameraButton: UIImage! = UIImage(named: "cameraIcon")

    // Creates a Button
    let cameraButton = UIButton(type: .Custom)
    // Sets width and height to the Button
    cameraButton.frame = CGRectMake(0.0, 0.0, imageCameraButton.size.width, imageCameraButton.size.height);
    // Sets image to the Button
    cameraButton.setBackgroundImage(imageCameraButton, forState: .Normal)
    // Sets the center of the Button to the center of the TabBar
    cameraButton.center = self.tabBar.center
    // Sets an action to the Button
    cameraButton.addTarget(self, action: "doSomething", forControlEvents: .TouchUpInside)

    // Adds the Button to the view
    self.view.addSubview(cameraButton)
}

我确实尝试以正常方式创建一个圆形按钮，但结果是这样的:

圆形按钮的代码片段:

//Creation of Ronded Button
    cameraButton.layer.cornerRadius = cameraButton.frame.size.width/2
    cameraButton.clipsToBounds = true

Answer 1

解决方案

您需要子类化 UITabBarController，然后在 TabBar 的 View 上方添加按钮。按钮操作应通过设置 selectedIndex 触发 UITabBarController 选项卡更改。

代码

下面的代码只是一个简单的方法，但是对于完整支持的 iPhone(包括 X 系列)/iPad 版本，您可以在此处查看完整的存储库:EBRoundedTabBarController

class CustomTabBarController: UITabBarController {

    // MARK: - View lifecycle

    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()
    }

    // MARK: - Setups

    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
        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
    }
}

输出