Swift延迟执行的四种方式

发表于

1.perform(必须在主线程中执行)

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self.perform(#selector(delayExecution), with: nil, afterDelay: 3)
取消
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NSObject.cancelPreviousPerformRequests(withTarget: self)

2.timer(必须在主线程中执行)

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Timer.scheduledTimer(timeInterval: 3, target: self, selector: #selector(delayExecution), userInfo: nil, repeats: false)

3.Thread (在主线程会卡主界面)

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Thread.sleep(forTimeInterval: 3)
self.delayExecution()

4.GCD 主线程/子线程

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DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
    self.delayExecution()
}
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DispatchQueue.global().asyncAfter(deadline: .now() + 3) {
    self.delayExecution()
}