下面是我的原代码:dispatch_once转换斯威夫特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)
}
}
}
为dispatch_once
已被删除,我纠正我可以安全地调用选择无过?例如:
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
if self.unauthorized {
self.performSelector(#selector(self.displayUnauthorizedMessage), withObject: nil, afterDelay: 0.5)
}
}
这是正确的吗?