在我的OS X中使用swift遇到了很多这个错误:
“这个应用程序正在从后台线程修改自动布局引擎,这可能会导致引擎损坏和奇怪的崩溃。这将在未来的版本中导致异常。”
我有一个NSWindow我将视图交换到窗口的contentView。当我尝试执行NSApp时会得到错误。或者当我向窗口添加子视图时。尝试禁用自动调整大小的东西,我没有任何使用自动布局的东西。任何想法吗?
有时它很好,什么都没有发生,其他时候它完全破坏了我的UI,什么都没有加载
在我的OS X中使用swift遇到了很多这个错误:
“这个应用程序正在从后台线程修改自动布局引擎,这可能会导致引擎损坏和奇怪的崩溃。这将在未来的版本中导致异常。”
我有一个NSWindow我将视图交换到窗口的contentView。当我尝试执行NSApp时会得到错误。或者当我向窗口添加子视图时。尝试禁用自动调整大小的东西,我没有任何使用自动布局的东西。任何想法吗?
有时它很好,什么都没有发生,其他时候它完全破坏了我的UI,什么都没有加载
当前回答
You already have the correct code answer from @Mark but, just to share my findings: The issue is that you are requesting a change in the view and assuming that it will happen instantly. In reality, the loading of a view depends on the available resources. If everything loads quickly enough and there are no delays then you don't notice anything. In scenarios, where there is any delay due to the process thread being busy etc, the application runs into a situation where it is supposed to display something even though its not ready yet. Hence, it is advisable to dispatch these requests in a asynchronous queues so, they get executed based on the load.
其他回答
I also encountered this problem, seeing a ton of these messages and stack traces being printed in the output, when I resized the window to a smaller size than its initial value. Spending a long time figuring out the problem, I thought I'd share the rather simple solution. I had once enabled Can Draw Concurrently on an NSTextView through IB. That tells AppKit that it can call the view's draw(_:) method from another thread. After disabling it, I no longer got any error messages. I didn't experience any problems before updating to macOS 10.14 Beta, but at the same time, I also started modifying the code to perform work with the text view.
它可以像设置文本字段/标签值或在后台线程中添加子视图一样简单,这可能会导致字段的布局发生变化。确保你对接口所做的任何事情都只发生在主线程中。
查看这个链接:https://forums.developer.apple.com/thread/7399
你不能在主线程中越位修改UI !UIKit不是线程安全的,所以如果你这样做,上面的问题和其他一些奇怪的问题会出现。应用程序甚至会崩溃。
所以,要做UIKit操作,你需要定义block并让它在主队列上执行:例如,
NSOperationQueue.mainQueue().addOperationWithBlock {
}
有同样的问题,因为我正在使用performSelectorInBackground。
当您尝试更新文本字段值或在后台线程中添加子视图时,可能会遇到此问题。因此,应该将这类代码放在主线程中。
您需要用dispatch_asynch包装调用UI更新的方法以获得主队列。例如:
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.friendLabel.text = "You are following \(friendCount) accounts"
})
编辑- swift 3:
现在,我们可以按照下面的代码来做:
// Move to a background thread to do some long running work
DispatchQueue.global(qos: .userInitiated).async {
// Do long running task here
// Bounce back to the main thread to update the UI
DispatchQueue.main.async {
self.friendLabel.text = "You are following \(friendCount) accounts"
}
}