尝试知道基于macOS Document的应用程序中的窗口何时关闭 [英] Trying to know when a window closes in a macOS Document based application

问题描述

我试图知道何时关闭窗口，我实现了以下代码：

  class ViewController：NSViewController，NSWindowDelegate { 
 
覆盖func viewDidLoad（）{
 super.viewDidLoad（）
 
让窗口：NSWindow吗？ = view.window 
 window？.delegate = self 
} 
 
 func windowWillClose（_ aNotification：Notification）{
 print（ windowWillClose）
 } 
 
} 
  

不幸的是什么都没有发生，我怎么可能做错了？ / p>

文档： https： //developer.apple.com/documentation/appkit/nswindow/1419400-willclosenotification

PS
我已经读过这个问题，没有找到解决方案：在Swift中处理窗口的关闭事件

解决方案

问题在于window属性将始终在viewDidLoadMethod内部返回nil。您需要在viewWillAppear方法内设置委托：

  class ViewController：NSViewController，NSWindowDelegate {
覆盖func viewWillAppear（） {
 super.viewWillAppear（）
 view.window？.delegate = self 
} 
 func windowWillClose（_ aNotification：Notification）{
 print（ windowWillClose） 
} 
} 
  

I'm trying to know when a window closes, I implemented this code:

class ViewController: NSViewController, NSWindowDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()

        let window: NSWindow? = view.window
        window?.delegate = self
    }

    func windowWillClose(_ aNotification: Notification) {
        print("windowWillClose")
    }

}

Unfortunately nothing happens, what could I made wrong?

Documents: https://developer.apple.com/documentation/appkit/nswindow/1419400-willclosenotification

PS I already read this question without to find a solution: Handle close event of the window in Swift

解决方案

The problem there is that the window property will always return nil inside viewDidLoadMethod. You need to set the delegate inside viewWillAppear method:

class ViewController: NSViewController, NSWindowDelegate {
    override func viewWillAppear() {
        super.viewWillAppear()
        view.window?.delegate = self
    }
    func windowWillClose(_ aNotification: Notification) {
        print("windowWillClose")
    }
}

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