问题
I've got a timer running in my Delphi MDI application and I'd like to use it to pop up a message if something changes in the background. But I don't want that message to pop up when the the application has a modal dialog in the foreground because the user couldn't do anything about it.
So what I'd like to know is how can I check for the existence of a modal dialog in my application?
回答1:
You could try with this code:
var
ActForm: TCustomForm;
begin
ActForm := Screen.ActiveForm;
if (ActForm = nil) or not (fsModal in ActForm.FormState) then begin
end;
end;
I tested with Delphi 4, works for me.
[EDIT]: But you should really think about whether popping up a form and stealing focus is a good idea. It depends on your application, but if a user is currently entering something into an edit field, or doing something with the mouse, then this might break their workflow.
回答2:
Since Delphi 2005 you have a ModalLevel property on TApplication. It counts the number of Modal forms opened in the application.
回答3:
Perhaps the solution is to actually pop up a hint which doesn't steal focus. A clickable hint somewhere visible, but not too invasive. Thus, if the user wants to take action they can, or they can finish off what they were doing, then take action. Or perhaps ignore it altogether.
回答4:
use AnyPopup() function
About GetLastActivePopup(). It may return value is the same as the hWnd parameter when
- The window identified by hWnd was most recently active.
- The window identified by hWnd does not own any pop-up windows.
- The window identifies by hWnd is not a top-level window, or it is owned by another window.
回答5:
Today user histrio correctly answered in another thread that just monitoring modal Delphi forms is not enough; Windows can also have modal dialogs.
His answer in another thread shows you how to check for that.
--jeroen
来源：https://stackoverflow.com/questions/284581/how-do-i-discover-if-my-delphi-application-currently-has-a-modal-window