下面是我的原代碼:dispatch_once轉換斯威夫特3
var checkUnauthorizedToken: dispatch_once_t = 0
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
dispatch_once(&checkUnauthorizedToken) {
if self.unauthorized {
self.performSelector(#selector(self.displayUnauthorizedMessage), withObject: nil, afterDelay: 0.5)
}
}
}
爲dispatch_once
已被刪除,我糾正我可以安全地調用選擇無過?例如:
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
if self.unauthorized {
self.performSelector(#selector(self.displayUnauthorizedMessage), withObject: nil, afterDelay: 0.5)
}
}
這是正確的嗎?