1
我無法理解,爲什麼在某些情況下我出現錯誤「擴展中的聲明無法覆蓋」,而在其他情況下則不是。奇怪的錯誤「擴展中的聲明無法覆蓋」
代碼:
protocol ConstrTest {
var goodConstraints: [NSLayoutConstraint] {get}
var badConstraints: [NSLayoutConstraint?] {get}
}
extension UIViewController: ConstrTest
{
var goodConstraints: [NSLayoutConstraint] {
return []
}
var badConstraints: [NSLayoutConstraint?] {
return []
}
}
class TestViewController: UIViewController {
override var goodConstraints: [NSLayoutConstraint] {
return []
} //No errors and it works
override var badConstraints: [NSLayoutConstraint?] {
return []
} //Got error Declarations in extensions cannot override
}
爲什麼我可以在此改變一個數組,不能覆蓋選配陣列?
可能是重複的https://stackoverflow.com/questions/34061246/override-function-error-in-swift – XmasRights