OS X app doesn't launch new window on dock icon press in Swift

问题

I am making a Mac app in Swift, and running into a problem. When my app is first launched from the terminated state, it automatically launches a new window. But if the user Xs out of my app (with the red X icon) instead of quitting it, then hits the app icon of my app, a new window doesn't automatically open.

How can I make my Mac app launch a new window every time the dock icon is hit, as long as there isn't already a window of my app open?

回答1:

Add this to your App Delegate:

func applicationShouldHandleReopen(theApplication: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
    if !flag {
        for window: AnyObject in theApplication.windows {
            window.makeKeyAndOrderFront(self)
        }
    }
    return true
}

回答2:

Don't forget to put

lazy var windows = NSWindow()

to somewhere at AppDelegate

and then implement

func applicationShouldHandleReopen(theApplication: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
        if !flag {
        for window: AnyObject in theApplication.windows {
            window.makeKeyAndOrderFront(self)
        }
    }
    return true
}

Like @Owlswipe wrote

来源：https://stackoverflow.com/questions/39400795/os-x-app-doesnt-launch-new-window-on-dock-icon-press-in-swift