检测右键单击上下文菜单osx

Question

How can I make sure a method gets called each time I expand a NSMenu. I have tried connecting the action from storyboard but the action only seem to get fired when i click menu items, not the menu itself.

[item setAction: @selector(play:)]

I would like to run a method when for instance the help menu gets expanded, to update the enabled and disabled content of that menu, since it is supposed to be different for logged in and not logged in users..

Update:

I added the NSMenuDelegate protocol in brackets in my

 @interface ClientAppDelegate : NSObject<NSApplicationDelegate,NSMenuDelegate>

Adding menu items work but the menu does not seem to affect the delegate methods.

// Create the application on the UI thread.
- (void)createApplication:(id)object {
  NSApplication* application = [NSApplication sharedApplication];
  [NSBundle loadNibNamed:@"MainMenu" owner:NSApp];

  // Set the delegate for application events.
  [application setDelegate:self];

  // Add the Tests menu.
  NSMenu* menubar = [application mainMenu];

  [menubar setDelegate:self];
    // TIDAL Create Controlls
    NSMenuItem *controlsItem = [[[NSMenuItem alloc] initWithTitle:@"Controls"
                                                           action:nil
                                                    keyEquivalent:@""] autorelease];
    NSMenu *controlsMenu = [[[NSMenu alloc] initWithTitle:@"Controls"] autorelease];
    AddMenuItem(controlsMenu, @"Pl",      ID_L_PL);

    [controlsItem setSubmenu:controlsMenu];
    [menubar addItem:controlsItem];


......


-(void) menuWillOpen:(NSMenu *)menu{
  wprintf(L"ITEM CLICK CAN I UPDATE MENU VISIBILITY HERE?");
}

-(void) menuNeedsUpdate:(NSMenu *)menu{
  wprintf(L"ITEM CLICK CAN I UPDATE MENU VISIBILITY HERE?");

}

Update2:

So I started over, imaginging that the problem had something to do with references and the fact that i was developing in objective-c++. However i can not get it to work in just a minimal Obj-C example either, below is my code. The only callback that seems to work is the one that handles item clicks. May the problem be present due to the fact that I am using :

  _menubar = [application mainMenu];

  [_menubar setDelegate:self];

To get my menubar and setup my menu delegate?

//
//  AppDelegate.m
//  menuTest
//
//  Created by David Karlsson on 27/02/15.
//  Copyright (c) 2015 David Karlsson. All rights reserved.
//

#import "AppDelegate.h"

void AddMenuItem(NSMenu *menu, NSString* label, int idval) {
  NSMenuItem* item = [menu addItemWithTitle:label
                                     action:@selector(menuItemSelected:)
                              keyEquivalent:@""];
  [item setTag:idval];
}


@interface AppDelegate ()

@property (weak) IBOutlet NSWindow *window;
@property (strong) IBOutlet NSMenu * menubar;
@end

@implementation AppDelegate


- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
  NSLog(@"Launched menu test");
  // Insert code here to initialize your application
  NSApplication* application = [NSApplication sharedApplication];
  //[NSBundle loadNibNamed:@"MainMenu" owner:NSApp];

  // Set the delegate for application events.
  [application setDelegate:self];

  // Add the Tests menu.
  _menubar = [application mainMenu];

  [_menubar setDelegate:self];

  NSMenuItem *controlsItem = [[NSMenuItem alloc] initWithTitle:@"Controls"
                                                        action:nil
                                                 keyEquivalent:@""];
  NSMenu *controlsMenu = [[NSMenu alloc] initWithTitle:@"Controls"];
  AddMenuItem(controlsMenu, @"1",      123);
  AddMenuItem(controlsMenu, @"2",    124);
  AddMenuItem(controlsMenu, @"3",  154);

  [controlsItem setSubmenu:controlsMenu];
  [_menubar addItem:controlsItem];


}

-(void) menuWillOpen:(NSMenu *)menu{
  NSLog(@"ITEM CLICK CAN I UPDATE MENU VISIBILITY HERE?");
}

-(void) menuNeedsUpdate:(NSMenu *)menu{
  NSLog(@"ITEM CLICK CAN I UPDATE MENU VISIBILITY HERE?");

}




- (void)applicationWillTerminate:(NSNotification *)aNotification {
  // Insert code here to tear down your application
  NSLog(@"Teardown menu test");
}

- (IBAction)menuItemSelected:(id)sender {
  // Retrieve the active RootWindow.
  NSWindow* key_window = [[NSApplication sharedApplication] keyWindow];
  if (!key_window){
    return;
  }



  NSLog(@"CLICK");
}


@end

Answer 1

Set the menu's delegate, then use this object to implement menuNeedsUpdate: from the NSMenuDelegate protocol. This method is called just before a menu is shown and is specifically provided to allow you to make changes to the menu in question before it arrives on screen.

Answer 2

您要实现NSMenu Delegate协议的某些部分，并且可能需要在菜单跟踪过程中工作的模式下运行的NSTimer，以便在菜单可见时进行实时更新。