Swift performSelector:withObject:afterDelay:不可用
我在Objective C中有一个正在过渡到Swift的应用程序。在Objective C中，我有这样的方法：
[self.view performSelector:@selector(someSelector) withObject:self afterDelay:0.1f];
我正在和Swift一起工作，但我不知道该怎么做。我试过了：
self.view.performSelector(Selector("someSelector"), withObject: self, afterDelay: 0.1)
下面是我得到的错误：'performSelector' is unavailable: 'performSelector' methods are unavailable
我将使用什么调用来调用方法afterDelay
更新
这是我最终得到的结论：
extension NSObject {
func callSelectorAsync(selector: Selector, object: AnyObject?, delay: NSTimeInterval) -> NSTimer {
let timer = NSTimer.scheduledTimerWithTimeInterval(delay, target: self, selector: selector, userInfo: object, repeats: false)
return timer
}
func callSelector(selector: Selector, object: AnyObject?, delay: NSTimeInterval) {
let delay = delay * Double(NSEC_PER_SEC)
let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
dispatch_after(time, dispatch_get_main_queue(), {
NSThread.detachNewThreadSelector(selector, toTarget:self, withObject: object)
})
}
}回答 3
Stack Overflow用户
发布于 2014-06-12 03:11:13
Swift 4
DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
// your function here
}Swift 3
DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(0.1)) {
// your function here
}Swift 2
let dispatchTime: dispatch_time_t = dispatch_time(DISPATCH_TIME_NOW, Int64(0.1 * Double(NSEC_PER_SEC)))
dispatch_after(dispatchTime, dispatch_get_main_queue(), {
// your function here
})Stack Overflow用户
发布于 2014-06-12 03:13:17
你可以这样做：
var timer = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: Selector("someSelector"), userInfo: nil, repeats: false)
func someSelector() {
// Something after a delay
}SWIFT 3
let timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(someSelector), userInfo: nil, repeats: false)
func someSelector() {
// Something after a delay
}Stack Overflow用户
发布于 2014-06-12 02:46:43
Swift是静态类型的，所以performSelector:方法会被搁置。
相反，使用GCD将合适的块分派到相关队列-在本例中，它可能是主队列，因为它看起来像是在做UIKit工作。
编辑：the Swift version of the NSRunLoop documentation中也明显缺少相关的performSelector: ("1 Objective-C symbol hidden")，所以你不能直接跳进去。考虑到这一点，再加上Swiftified NSObject中没有苹果，我认为苹果的想法很明显。
https://stackoverflow.com/questions/24170282
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