blocks|key|2938041|text|UIKit不是线程安全的。UI应该只从主线程更新：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2938042|dispatch_async(dispatch_get_main_queue())+{
++++self.tableView.reloadData()
}|code-block|syntax|javascript|2938043|更新。在Swift+3和更高版本中使用：|offset|length|style|BOLD|2938044|DispatchQueue.main.async+{
++++self.tableView.reloadData()
}|2938045|entityMap^0|0|0|0|2|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

UIKit isn't thread safe. The UI should only be updated from main thread:

<pre><code>dispatch_async(dispatch_get_main_queue()) {
 self.tableView.reloadData()
}
</code></pre>

Update. In Swift 3 and later use:

<pre><code>DispatchQueue.main.async {
 self.tableView.reloadData()
}
</code></pre>

blocks|key|2938079|text|您也可以像这样重新加载UITableView|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2938080|self.tblMainTable.performSelectorOnMainThread(Selector("reloadData"),+withObject:+nil,+waitUntilDone:+true)|code-block|syntax|javascript|2938081|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can also reload UITableView like this

<pre><code>self.tblMainTable.performSelectorOnMainThread(Selector("reloadData"), withObject: nil, waitUntilDone: true)
</code></pre>

blocks|key|145457|text|您还可以使用NSOperationQueue.mainQueue()更新主线程。对于多线程，NSOperationQueue是一个很棒的工具。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|145458|一种方式可以写成：|145459|NSOperationQueue.mainQueue().addOperationWithBlock({
+++++self.tableView.reloadData()+++++++
})|code-block|syntax|javascript|145460|更新：DispatchQueue+is+the+way+to+go+for+this|BOLD|145461|更新2：Use+DispatchQueue+solution+as+seen+in+accepted+answer+above|145462|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/27858064/4970749|1|https://stackoverflow.com/a/26277519/4970749^0|6|S|0|0|0|0|2|3|13|0|0|0|3|4|1N|1|0^^$0|@$1|2|3|4|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|14|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|15|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|16|8|@$9|17|A|18|B|O]]|D|@$9|19|A|1A|1|1B]]|E|$]]|$1|P|3|Q|5|6|7|1C|8|@$9|1D|A|1E|B|O]]|D|@$9|1F|A|1G|1|1H]]|E|$]]|$1|R|3|-4|5|6|7|1I|8|@]|D|@]|E|$]]]|S|$T|$5|U|V|W|E|$X|Y]]|Z|$5|U|V|W|E|$X|10]]]]

You can also update the main thread using <code>NSOperationQueue.mainQueue()</code>. For multithreading, NSOperationQueue is a great tool.
One way it could be written:
<pre><code>NSOperationQueue.mainQueue().addOperationWithBlock({
 self.tableView.reloadData() 
})
</code></pre>
Update: <a href="https://stackoverflow.com/a/27858064/4970749">DispatchQueue is the way to go for this</a>
Update 2: <a href="https://stackoverflow.com/a/26277519/4970749">Use DispatchQueue solution as seen in accepted answer above</a>

blocks|key|149348|text|使用Swift+3|type|unstyled|depth|inlineStyleRanges|entityRanges|data|149349|DispatchQueue.main.async+{
++++self.tableView.reloadData()
}|code-block|syntax|javascript|149350|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

With Swift 3 use 

<pre><code>DispatchQueue.main.async {
 self.tableView.reloadData()
}
</code></pre>

blocks|key|2725920|text|SWIFT+3：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2725921|OperationQueue.main.addOperation+({
+++++self.tableView.reloadData()
})|code-block|syntax|javascript|2725922|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

SWIFT 3: 

<pre><code>OperationQueue.main.addOperation ({
 self.tableView.reloadData()
})
</code></pre>

blocks|key|2725936|text|DispatchQueue.main.async+{
++++self.tableView.reloadData()
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2725937|执行此操作可更新主线程上的UI。使用此方法，它将带来更新表视图并在UI中反映数据。|unstyled|2725938|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>DispatchQueue.main.async {
 self.tableView.reloadData()
}
</code></pre>
Do this to update the UI on the main thread. Using this method it will bring update the table view and reflect the data in the UI.

blocks|key|2938189|text|我建议进一步改进它(从swift+3开始)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|2938190|struct+UIHelper+{
++++static+func+performUpdate(using+closure:+@escaping+()+->+Void)+{
++++++++if+Thread.isMainThread+{
++++++++++++closure()
++++++++}+else+{
++++++++++++DispatchQueue.main.async(execute:+closure)
++++++++}
++++}
}|code-block|syntax|javascript|2938191|然后：|2938192|UIHelper.performUpdate+{
++++self.tableView.reloadTable()
}|2938193|这样做的原因是，有时调用是在主线程上进行的，因此不需要在异步线程上执行UI更新。|2938194|entityMap^0|B|7|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$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]]|$1|O|3|P|5|6|7|Y|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

I suggest to improve it one step further (starting from swift 3):
<pre><code>struct UIHelper {
 static func performUpdate(using closure: @escaping () -&gt; Void) {
 if Thread.isMainThread {
 closure()
 } else {
 DispatchQueue.main.async(execute: closure)
 }
 }
}
</code></pre>
And then:
<pre><code>UIHelper.performUpdate {
 self.tableView.reloadTable()
}
</code></pre>
The reason for this is that sometimes the call is made on main thread, so there's no need to execute UI update on async thread.

I believe I'm having an issue where my closure is happening on a background thread and my UITableView isn't updating fast enough. I am making a call to a REST service and in my closure i have a <code>tableView.reloadData()</code> call but it takes a few seconds for this to happen. How do I make the data reload faster (perhaps on the main thread?)

REST Query Function - using SwiftyJSON library for Decoding

<pre><code>func asyncFlightsQuery() {
 var url : String = "http://127.0.0.1:5000/flights"
 var request : NSMutableURLRequest = NSMutableURLRequest()
 request.URL = NSURL(string: url)
 request.HTTPMethod = "GET"

 NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue(), completionHandler:{ (response:NSURLResponse!, networkData: NSData!, error: NSError!) -&gt; Void in
 var error: AutoreleasingUnsafeMutablePointer&lt;NSError?&gt; = nil


 // Parse with SwiftyJSON
 let json = JSON(data: networkData)

 // Empty out Results array
 self.resultArray = []

 // Populate Results Array
 for (key: String, subJson: JSON) in json["flights"] {
 print ("KEY: \(key) ")
 print (subJson["flightId"])
 print ("\n")

 self.resultArray.append(subJson)
 }

 print ("Calling reloadData on table..??")
 self.tableView.reloadData()


 })
}
</code></pre>

Once <code>self.tableView.reloadData()</code> is called in my debugger

Swift UITableView reloadData in a closure

调试器

Swift

JSON

我相信我有一个问题，我的关闭发生在后台线程上，并且我的UITableView更新得不够快。我正在调用一个REST服务，在我的闭包中，我有一个tableView.reloadData()调用，但这需要几秒钟的时间。如何让数据重载更快(也许是在主线程上？)REST查询函数-使用SwiftyJSON库解码func async...

问闭包中的Swift UITableView reloadData
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