ios Swift performSelector:withObject:afterDelay: 不可用
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/24170282/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Swift performSelector:withObject:afterDelay: is unavailable
提问by Cody Winton
I have an app in Objective C that I'm transitioning to Swift. In Objective C, I have this method:
我在 Objective C 中有一个应用程序，我正在过渡到 Swift。在目标 C 中，我有这个方法：
[self.view performSelector:@selector(someSelector) withObject:self afterDelay:0.1f];
[self.view performSelector:@selector(someSelector) withObject:self afterDelay:0.1f];
I'm working with Swift and I can't figure out how to do this. I've tried:
我正在与 Swift 合作，但我不知道如何做到这一点。我试过了：
self.view.performSelector(Selector("someSelector"), withObject: self, afterDelay: 0.1)
self.view.performSelector(Selector("someSelector"), withObject: self, afterDelay: 0.1)
Here's the error that I get: 'performSelector' is unavailable: 'performSelector' methods are unavailable
这是我得到的错误： 'performSelector' is unavailable: 'performSelector' methods are unavailable
What call would I use to call a method afterDelay?
我将使用什么调用来调用方法afterDelay？
UPDATE
更新
Here's what I ended up with:
这是我的结果：
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by brandonscript
Swift 4
斯威夫特 4
DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
// your function here
}
Swift 3
斯威夫特 3
DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(0.1)) {
// your function here
}
Swift 2
斯威夫特 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
})
回答by StevenOjo
You could do this:
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
斯威夫特 3
let timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(someSelector), userInfo: nil, repeats: false)
func someSelector() {
// Something after a delay
}
回答by Tommy
Swift is statically typed so the performSelector:methods are to fall by the wayside.
Swift 是静态类型的，因此performSelector:方法将被搁置一旁。
Instead, use GCD to dispatch a suitable block to the relevant queue — in this case it'll presumably be the main queue since it looks like you're doing UIKit work.
相反，使用 GCD 将合适的块分派到相关队列——在这种情况下，它可能是主队列，因为它看起来像是在做 UIKit 工作。
EDIT: the relevant performSelector:is also notably missing from the Swift version of the NSRunLoopdocumentation("1 Objective-C symbol hidden") so you can't jump straight in with that. With that and its absence from the Swiftified NSObjectI'd argue it's pretty clear what Apple is thinking here.
编辑：文档的 Swift 版本中performSelector:也明显缺少相关内容（“隐藏 1 个 Objective-C 符号”），因此您无法直接使用它。有了它以及它在 Swiftified 中的缺席，我认为很清楚 Apple 在这里的想法。NSRunLoopNSObject
