Mac状态栏应用设置视图启动及关闭后重启问题咨询

Hey there! Let's work through getting your settings view up and running properly, and tackle that restart-after-close functionality too. The NSWorkspace.shared().launchApplication("AppName") approach isn't right here because it tries to spin up a whole new instance of your app—instead, we need to show the settings view directly from your running status bar process.

Step 1: Show the Settings View Properly #

First, your settings view should be wrapped in an NSWindowController (or NSViewController if you're using storyboards). Here's how to trigger it from your NSMenuItem:

1. Create a window controller for your settings (let's say you have a XIB named SettingsWindow):

   import Cocoa
   
   class SettingsWindowController: NSWindowController {
       override var windowNibName: NSNib.Name? {
           return NSNib.Name("SettingsWindow")
       }
   }
   

2. In your app's main logic (like AppDelegate or the menu handler), add a property to hold the window controller (this prevents it from being deallocated when the window closes):

   private var settingsWindowController: SettingsWindowController?
   

3. Add the action method for your NSMenuItem:

   @IBAction func showSettings(_ sender: NSMenuItem) {
       // Create the controller if it doesn't exist yet
       if settingsWindowController == nil {
           settingsWindowController = SettingsWindowController()
       }
       
       // Show the window and bring it to the front
       settingsWindowController?.showWindow(self)
       settingsWindowController?.window?.makeKeyAndOrderFront(nil)
       
       // If your app is a LSUIElement (no Dock icon), activate it to ensure the window responds to input
       NSApp.activate(ignoringOtherApps: true)
   }
   

Step 2: Handle Restarting the View After Close #

There are two scenarios here—let's cover both:

Scenario 1: Reopen the settings view when the user clicks the menu again after closing it #

The code above already handles this! Since we're holding onto the settingsWindowController reference, closing the window just hides it. The next time the user clicks the menu, showWindow() will bring it back. If you want to completely reset the view each time (instead of reusing it), just set settingsWindowController = nil when the window closes:

// Add this to your SettingsWindowController
override func windowWillClose(_ notification: Notification) {
    // Tell the parent to release the controller
    if let appDelegate = NSApp.delegate as? AppDelegate {
        appDelegate.settingsWindowController = nil
    }
}

Scenario 2: Auto-open the settings view when your app restarts (after being closed) #

To do this, use UserDefaults to store a flag that tells the app to open settings on launch:

1. In your AppDelegate, check the flag when the app finishes launching:

   func applicationDidFinishLaunching(_ aNotification: Notification) {
       let defaults = UserDefaults.standard
       if defaults.bool(forKey: "ShouldOpenSettingsOnLaunch") {
           showSettings(NSMenuItem()) // Trigger the settings view
           defaults.set(false, forKey: "ShouldOpenSettingsOnLaunch") // Reset the flag
       }
   }
   

2. Set the flag when you want the app to open settings on next restart (e.g., when the user closes the settings window, or when they exit the app):

   // Example: Set the flag when the settings window closes
   override func windowWillClose(_ notification: Notification) {
       UserDefaults.standard.set(true, forKey: "ShouldOpenSettingsOnLaunch")
   }
   

Key Notes to Avoid Common Pitfalls #

• Don't use NSWorkspace to launch your own app: This creates a duplicate instance, which is almost never what you want for a status bar app.
• LSUIElement considerations: If your app has LSUIElement = YES in Info.plist (no Dock icon), make sure to call NSApp.activate(ignoringOtherApps: true) when showing the settings window—otherwise, the window might not receive user input.
• Single instance guarantee: Ensure your app only runs one instance. You can enforce this by adding a check in applicationDidFinishLaunching or setting LSBackgroundOnly = YES (though the latter has other implications).

内容的提问来源于stack exchange，提问作者Antoine