如何重新打开应用程序窗口，Xcode

Question

I am reading "Cocoa programming for OS X" (The Big Neard Ranch Guid) and I have made a simplest application to test an empty windows app with a window controller and xib file for this controller. I have wrote all necessary code according to the book but after building the app and closing the window of app I cannot reopen the window of the app. What is wrong ? Below the code. (I deleted window in MainMenu.xib and accordingly changed AppDelegate; and Visible at Launch box is unchecked) ). The book says that showWindow(_:) will reopen the window, but I don't see this !

import Cocoa

 @NSApplicationMain
 class AppDelegate: NSObject, NSApplicationDelegate {

var control: Control?

func applicationDidFinishLaunching(aNotification: NSNotification) {

    //Create a window controller object
    let control = Control()

    //Put the window of the window controler om the screen
    control.showWindow(self)

    //Set the propertity to point to window controler
    self.control = control

}


func applicationWillTerminate(aNotification: NSNotification) {
    // Insert code here to tear down your application
}


}

in my controller class

import Cocoa
class Control: NSWindowController
{
    override var windowNibName: String?
        {
            return "Control"
}
}

In File's Owner identity is for Control controller and window has been connected to window outlet.

Answer 1

You have to add the following application delegate method.

func applicationShouldHandleReopen(sender: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
    if flag {
        control.window.orderFront(self)
    } else {
        control.window.makeKeyAndOrderFront(self)
    }
    return true
}