swift - windowShouldClose(_ :) delegate function not being called in code

Question

我目前正在尝试通过一本 Mac Apps 书籍学习 Cocoa，其中一个程序具有 windowShouldClose(_:) 委托(delegate)函数。但是，当我运行程序时，只要调用此函数，窗口仍会关闭。程序仍在运行，但窗口关闭。谁能解释为什么会这样？这是我的代码:

import Cocoa

class MainWindowController: NSWindowController, NSSpeechSynthesizerDelegate, NSWindowDelegate {

@IBOutlet weak var textField: NSTextField!
@IBOutlet weak var speakButton: NSButton!
@IBOutlet weak var stopButton: NSButton!

let speechSynth = NSSpeechSynthesizer()

var isStarted: Bool = false {
    didSet {
        updateButtons()
    }
    }

override var windowNibName: String {
    return "MainWindowController"
}

override func windowDidLoad() {
    super.windowDidLoad()
    updateButtons()
    speechSynth.delegate = self
}

//MARK: - Action methods

//get typed-in text as string
@IBAction func speakIt(sender: NSButton){
    let string = textField.stringValue
    if string.isEmpty {
        print("string from \(textField) is empty")
    } else{
        speechSynth.startSpeakingString(string)
        isStarted = true
        }

    }
@IBAction func stopIt(sender: NSButton){
    speechSynth.stopSpeaking()
}

func updateButtons(){
    if isStarted{
        speakButton.enabled = false
        stopButton.enabled = true
    } else {
        speakButton.enabled = true
        stopButton.enabled = false
    }
}

//Mark: NSSpeechSynthDelegate
func speechSynthesizer(sender: NSSpeechSynthesizer, didFinishSpeaking finishedSpeaking: Bool){
    isStarted = false
    print("finished speaking=\(finishedSpeaking)")
}

//Mark: Window Delegate
func windowShouldClose(sender: AnyObject) -> Bool {
    return !isStarted
}
}

谢谢!

Answer 1

您需要将主视图 Controller 设置为 NSWindow 的委托(delegate)。

在您的 windowDidLoad 中，您可以将 self 设置为窗口的委托(delegate)

override func windowDidLoad() {
    super.windowDidLoad()
    updateButtons()
    speechSynth.delegate = self
    self.window.delegate = self
}