blocks|key|4408117|text|经过大量的研究，我终于弄明白了这一点。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408118|DispatchQueue.main.asyncAfter(deadline:+.now()+%2B+2.0)+{+//+Change+`2.0`+to+the+desired+number+of+seconds.
+++//+Code+you+want+to+be+delayed
}|code-block|syntax|javascript|4408119|这在Swift+3和Swift+4中创建了所需的“等待”效果。|4408120|灵感来自this+answer的一部分。|offset|length|4408121|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/24034838/5700898^0|0|0|0|4|B|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|X|8|@]|9|@$K|Y|L|Z|1|10]]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

After a lot of research, I finally figured this one out.

<pre><code>DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) { // Change `2.0` to the desired number of seconds.
 // Code you want to be delayed
}
</code></pre>

This creates the desired "wait" effect in Swift 3 and Swift 4.

Inspired by a part of <a href="https://stackoverflow.com/a/24034838/5700898">this answer</a>.

blocks|key|4408328|text|//x秒后运行函数|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408329|public+static+func+runThisAfterDelay(seconds:+Double,+after:+@escaping+()+->+Void)+{
++++runThisAfterDelay(seconds:+seconds,+queue:+DispatchQueue.main,+after:+after)
}

public+static+func+runThisAfterDelay(seconds:+Double,+queue:+DispatchQueue,+after:+@escaping+()+->+Void)+{
++++let+time+=+DispatchTime.now()+%2B+Double(Int64(seconds+*+Double(NSEC_PER_SEC)))+/+Double(NSEC_PER_SEC)
++++queue.asyncAfter(deadline:+time,+execute:+after)
}|code-block|syntax|javascript|4408330|//使用：-|4408331|runThisAfterDelay(seconds:+x){
++//write+your+code+here
}|4408332|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

//Runs function after x seconds

<pre><code>public static func runThisAfterDelay(seconds: Double, after: @escaping () -&gt; Void) {
 runThisAfterDelay(seconds: seconds, queue: DispatchQueue.main, after: after)
}

public static func runThisAfterDelay(seconds: Double, queue: DispatchQueue, after: @escaping () -&gt; Void) {
 let time = DispatchTime.now() + Double(Int64(seconds * Double(NSEC_PER_SEC))) / Double(NSEC_PER_SEC)
 queue.asyncAfter(deadline: time, execute: after)
}
</code></pre>

//Use:-

<pre><code>runThisAfterDelay(seconds: x){
 //write your code here
}
</code></pre>

blocks|key|4408358|text|一种方法是使用DispatchQueue.main.asyncAfter，因为很多人已经回答了。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4408359|另一种方法是使用perform(_:with:afterDelay:)。More+details+here|4408360|perform(#selector(delayedFunc),+with:+nil,+afterDelay:+3)

@IBAction+func+delayedFunc()+{
++++//+implement+code
}|code-block|syntax|javascript|4408361|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.apple.com/documentation/objectivec/nsobject/1416176-perform^0|7|T|0|8|R|10|H|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|X|8|@$9|Y|A|Z|B|C]]|D|@$9|10|A|11|1|12]]|E|$]]|$1|H|3|I|5|J|7|13|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

One way is to use <code>DispatchQueue.main.asyncAfter</code> as a lot of people have answered.

Another way is to use <code>perform(_:with:afterDelay:)</code>. <a href="https://developer.apple.com/documentation/objectivec/nsobject/1416176-perform" rel="nofollow noreferrer">More details here</a>

<pre><code>perform(#selector(delayedFunc), with: nil, afterDelay: 3)

@IBAction func delayedFunc() {
 // implement code
}
</code></pre>

blocks|key|4408399|text|最常用的是asyncAfter()和Timer。但是如果阻塞线程是OK的，那么有一个选项：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4408400|sleep(3)+//+in+seconds
usleep+++//+in+1/million+of+second+|code-block|syntax|javascript|4408401|对于异步编程(Swift+5.5)，在func中暂停如下所示：|4408402|func+someAsyncFunc()+async+{
++++await+Task.sleep(2_000_000_000)++//+Two+seconds
++++//+Code+to+be+executed+with+a+delay+here
}|4408403|entityMap^0|5|C|I|5|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

Most common things to use are <code>asyncAfter()</code> and <code>Timer</code>. But if blocking thread is OK, then there is an option:
<pre><code>sleep(3) // in seconds
usleep // in 1/million of second 
</code></pre>
For asynchronous programming (Swift 5.5) pausing in func looks like this:
<pre><code>func someAsyncFunc() async {
 await Task.sleep(2_000_000_000) // Two seconds
 // Code to be executed with a delay here
}
</code></pre>

In earlier versions of Swift, one could create a delay with the following code:

<pre><code>let time = dispatch_time(dispatch_time_t(DISPATCH_TIME_NOW), 4 * Int64(NSEC_PER_SEC))
dispatch_after(time, dispatch_get_main_queue()) {
 //put your code which should be executed with a delay here
}
</code></pre>

But now, in Swift 3, Xcode automatically changes 6 different things but then the following error appears: "Cannot convert <code>DispatchTime.now</code> to expected value <code>dispatch_time_t</code> aka <code>UInt64</code>."

How can one create a delay before running a sequence of code in Swift 3?

How to program a delay in Swift 3

Swift

Xcode

在Swift的早期版本中，可以使用以下代码创建延迟：let time = dispatch_time(dispatch_time_t(DISPATCH_TIME_NOW), 4 * Int64(NSEC_PER_SEC))dispatch_after(time, dispatch_get_main_queue()) {...

问如何在Swift 3中编程延迟
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