我正在尝试加载基于按钮按下的 View 。我想我可以在下面做这样的事情,我定义了一个通用的 UIViewController,然后将它设置为 switch/case 语句中的特定 UIViewController,但它显然不能这样工作。我做错了什么?
@objc func menuButton(sender: UIButton) {
var view: UIViewController!
switch sender.tag {
case 0:
view = MenuViewController()
view.menuType = .Account
case 1:
view = MenuViewController()
view.menuType = .Sync
case 2:
view = AuthViewController()
view.menuType = .Auth
default: break
}
self.navigationController?.pushViewController(view, animated: true)
}
最佳答案
如果我没记错的话,编译器应该会报错:
Value of type 'UIViewController' has no member 'menuType'
这里有几个选项可以解决这个问题:
解决方案一
使用转换
@objc func menuButton(sender: UIButton) {
var view: UIViewController!
switch sender.tag {
case 0:
view = MenuViewController()
(view as? MenuViewController())?.menuType = .Account
case 1:
view = MenuViewController()
(view as? MenuViewController())?.menuType = .Sync
case 2:
view = AuthViewController()
(view as? AuthViewController())?.menuType = .Auth
default: break
}
self.navigationController?.pushViewController(view, animated: true)
}
方案二
创建协议(protocol)MenuProtocol
protocol MenuProtocol {
var menuType: MenuType { get set }
}
并使 MenuViewController
和 AuthViewController
实现该协议(protocol)。然后您可以执行以下操作:
@objc func menuButton(sender: UIButton) {
var view: (UIViewController & MenuProtocol)!
switch sender.tag {
case 0:
view = MenuViewController()
view.menuType = .Account
case 1:
view = MenuViewController()
view.menuType = .Sync
case 2:
view = AuthViewController()
view.menuType = .Auth
default: break
}
self.navigationController?.pushViewController(view, animated: true)
}
关于swift - 使用 Swift 在 switch/case 语句中设置 UIViewController,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/49277496/