How can I make a menu stay visible after it's clicked?

I'm using Delphi. I have my popup menu ready, and in a submenu I want to click, but I don't want the popup menu to disappear. I want to click a开发者_JAVA百科nd make it stay.

Easy one, disable the item. < g >

Joke aside, not an easy task.

If you want the popup menu to act like a top-most form (that is you can both interact with the items and with controls on your form without deactivating the menu), forget it, it cannot be done with a standard menu.

But if your requirement is as exactly as stated in your question (click an item, and the menu is not closed - click outside and it is closed), with some work, it would be possible.

Your aim would be to subclass the window that your submenu will reside in to override some message handling. First, derive a new class from 'TPopupList' and override its 'WndProc'. Here is an example doing this.

If you intend to prevent the closing of the menu by selecting root items then in PopupList's WndProc you'd handle WM_ENTERIDLE and get the popup menu's window handle from the message's lParam and subclass the popup menu's window.

If you only intend to prevent the closing of the menu by selecting submenu items, then in PopupList's WndProc you'd watch for WM_INITMENUPOPUP messages where the wParam is "not" the handle of the PopupMenu itself, that would mean a submenu is about to be shown. Only then you'd handle WM_ENTERIDLE and get the window handle that the submenu resides in and subclass that window.

After subclassing the window that the popup menu or the popup submenu resides in, you'd intercept an undocumented 'MN_BUTTONDOWN' ($01ED) message and prevent further handling (not call the original window procedure). Probably you'd also want to prevent closing of the menu with the keyboard; you'd watch for WM_KEYDOWN (Enter) and WM_CHAR (accelerator) messages.

Well, would take some work I guess.

I don't know how can you do that but TAdvStickyPopupMenu component (TMS software) can do this.