挂机退出应用程序并显示警报

Question

我需要在用户通过单击x按钮退出应用程序时显示警告框。如何挂接应用程序的退出事件并显示警报或视图通过赛格瑞

performSegue(withIdentifier: "segue", sender: nil) 

请咨询控制器..

Answer 1

在你的appdelegate你应该能够把你的代码放到applicationWillTerminate，使消息出现在那里。

编辑：你可能会更好使用模态警报，而不是一个segue。

Answer 2

我知道你想用segue来做到这一点，因为它们只是非常方便，但是在应用程序委托事件（如“applicationWillResignActive”（前往后台）或“applicationWillBecomeActive” “（再次成为前景）。

正确的做法是通过警报。你可能想在applicationShouldTerminate中这样做，因为你可能想要A）如果你有一个很好的理由不放弃，或者B）给用户一个选择是否真的退出。

下面是它会怎样看在SWIFT 4：

var licenseWindowController : LicenseWindowController? 

func dialogOKCancel(question: String, text: String) -> Bool { 
    let alert = NSAlert() 
    alert.messageText = question 
    alert.informativeText = text 
    alert.alertStyle = .warning 
    alert.addButton(withTitle: "OK") 
    alert.addButton(withTitle: "Cancel") 
    return alert.runModal() == .alertFirstButtonReturn 
} 

func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply { 

    let answer = dialogOKCancel(question: "Ok?", text: "Should we really quit?") 
    if answer == true 
    { 
     return .terminateNow 
    } else { 

func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply { 

    let answer = dialogOKCancel(question: "Ok?", text: "Should we really quit?") 
    if answer == true 
    { 

     return .terminateNow 

    } else { 

     // to bring up a window from your storyboard... 
     let mainStoryboard = NSStoryboard.init(name: NSStoryboard.Name(rawValue: "Main"), bundle: nil) 
     self.licenseWindowController = mainStoryboard.instantiateController(withIdentifier: NSStoryboard.SceneIdentifier(rawValue: "LicenseWindowController")) as? LicenseWindowController 
     if let actualLicenseWC = self.licenseWindowController 
     { 
      actualLicenseWC.showWindow(self) 
     } 

     return .terminateCancel 
    } 
} 

斯威夫特3

var licenseWindowController : LicenseWindowController? 

func dialogOKCancel(question: String, text: String) -> Bool { 
    let alert = NSAlert() 
    alert.messageText = question 
    alert.informativeText = text 
    alert.alertStyle = .warning 
    alert.addButton(withTitle: "OK") 
    alert.addButton(withTitle: "Cancel") 
    return alert.runModal() == NSAlertFirstButtonReturn 
} 

func applicationShouldTerminate(_ sender: NSApplication) -> NSApplicationTerminateReply { 

    let answer = dialogOKCancel(question: "Ok?", text: "Should we really quit?") 
    if answer == true 
    { 
     return .terminateNow 
    } else { 
     let mainStoryboard = NSStoryboard.init(name: "Main", bundle: nil) 
     self.licenseWindowController = mainStoryboard.instantiateController(withIdentifier: "LicenseWindowController") as? LicenseWindowController 
     if let actualLicenseWC = self.licenseWindowController 
     { 
      actualLicenseWC.showWindow(self) 
     } 

     return .terminateCancel 
    } 
}