问题
Is it possible to make a window to go over the menu bar, without going in fullscreen?
Thanks in Advance!
回答1:
Yes, trivially:
window.level = NSMainMenuWindowLevel + 1;
(Reference: Drawing to the Full Screen, OpenGL Programming Guide for Mac OS X.)
sebastianmarkow is correct in that this is terrible behaviour for a normal document window, but there are several window types for which this is normal: cursors, tool tips, and special utilities like Xscope.
回答2:
I liked Jens Ayton's answer, but rather than pick an arbitrary number like that, I think it would be preferred that you use one of the defined constants.
Personally, I used NSPopUpMenuWindowLevel as in:
self.window.level = NSPopUpMenuWindowLevel;
Other constants that you might prefer, as of my posting this answer, include:
NSNormalWindowLevelNSFloatingWindowLevelNSSubmenuWindowLevelNSNormalWindowLevelNSMainMenuWindowLevelNSStatusWindowLevelNSModalPaneWindowLevelNSPopUpMenuWindowLevelNSScreenSaverWindowLevel
Here's the reference (Apple has a tendency to change how they organize their docs and break these links over the years, but the APIs don't change much, which is why I included that list above. I doubt this link will work in 3 years or so, but these constants probably won't change much in the next 20 years.)
https://developer.apple.com/library/mac/documentation/cocoa/reference/applicationkit/classes/NSWindow_Class/Reference/Reference.html#//apple_ref/doc/constant_group/Window_Levels
回答3:
I do not believe that you can go on top of the menu bar, but you can set the menu bar to auto-hide when your application is the frontmost application by calling
[[NSApplication sharedApplication] setPresentationOptions: NSApplicationPresentationAutoHideMenuBar];
Which should let you use the space normally used for the menu bar in your application.
来源：https://stackoverflow.com/questions/6772515/mac-os-x-make-a-window-go-over-menu-bar