在实例化 UISegementedControl 的子 class 时使用未实现的初始值设定项 'init(frame:)' for class
Use of unimplemented initializer 'init(frame:)' for class when instantiating a subclass of UISegementedControl
当我尝试在下面的代码中使用 MySegmentControl
的实例时出现以下错误。错误发生在应用程序启动后。
知道我错过了什么吗?
Fatal error: Use of unimplemented initializer 'init(frame:)' for class 'TestingSubclassing.MySegmentControl'
UISegementedControl 的子类
导入 UIKit
class MySegmentControl: UISegmentedControl {
init(actionName: Selector) {
let discountItems = ["One" , "Two"]
super.init(items: discountItems)
self.selectedSegmentIndex = 0
self.layer.cornerRadius = 5.0
self.backgroundColor = UIColor.red
self.layer.borderWidth = 1
self.layer.borderColor = UIColor.blue.cgColor
self.addTarget(self, action: actionName, for: .valueChanged)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
ViewController
import UIKit
class ViewController: UIViewController {
let segmentOne: MySegmentControl = {
let segment1 = MySegmentControl(actionName: #selector(segmentAction))
return segment1
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(segmentOne)
}
@objc func segmentAction (sender: UISegmentedControl) {
print("segmentAction")
}
}
您可以调用 super.init(frame
并手动插入段 。
并且您必须向自定义 init(actionName
方法添加一个 target
参数。
class MySegmentControl: UISegmentedControl {
init(actionName: Selector, target: Any?) {
super.init(frame: .zero)
insertSegment(withTitle: "Two", at: 0, animated: false)
insertSegment(withTitle: "One", at: 0, animated: false)
self.selectedSegmentIndex = 0
self.layer.cornerRadius = 5.0
self.backgroundColor = UIColor.red
self.layer.borderWidth = 1
self.layer.borderColor = UIColor.blue.cgColor
self.addTarget(target, action: actionName, for: .valueChanged)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
当我尝试在下面的代码中使用 MySegmentControl
的实例时出现以下错误。错误发生在应用程序启动后。
知道我错过了什么吗?
Fatal error: Use of unimplemented initializer 'init(frame:)' for class 'TestingSubclassing.MySegmentControl'
UISegementedControl 的子类
导入 UIKit
class MySegmentControl: UISegmentedControl {
init(actionName: Selector) {
let discountItems = ["One" , "Two"]
super.init(items: discountItems)
self.selectedSegmentIndex = 0
self.layer.cornerRadius = 5.0
self.backgroundColor = UIColor.red
self.layer.borderWidth = 1
self.layer.borderColor = UIColor.blue.cgColor
self.addTarget(self, action: actionName, for: .valueChanged)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
ViewController
import UIKit
class ViewController: UIViewController {
let segmentOne: MySegmentControl = {
let segment1 = MySegmentControl(actionName: #selector(segmentAction))
return segment1
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(segmentOne)
}
@objc func segmentAction (sender: UISegmentedControl) {
print("segmentAction")
}
}
您可以调用 super.init(frame
并手动插入段 。
并且您必须向自定义 init(actionName
方法添加一个 target
参数。
class MySegmentControl: UISegmentedControl {
init(actionName: Selector, target: Any?) {
super.init(frame: .zero)
insertSegment(withTitle: "Two", at: 0, animated: false)
insertSegment(withTitle: "One", at: 0, animated: false)
self.selectedSegmentIndex = 0
self.layer.cornerRadius = 5.0
self.backgroundColor = UIColor.red
self.layer.borderWidth = 1
self.layer.borderColor = UIColor.blue.cgColor
self.addTarget(target, action: actionName, for: .valueChanged)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}