How do I send a message to my MDI-child windows 1

[TimSNL]

Hello,

My application has many MDI windows that may be opened during use.

Is there a way to somehow broadcast a message from the MDI-parent (in a generic way) that all the MDI-child windows can act on if required?

I have not used any type of window messaging before so any hints to point me in the right directin would be appriciated.

Thanks for your help
(Replies to my last post were very helpful, thankyou everyone)

Tim
SNL Computing

 

[McMerfy]

For broadcasting you can use PostMessage(HWND_BROADCAST, WM_MY_MESSAGE, wParam, lParam). That message would be recieved by ALL windows. And if you want to send message to your MDI child forms only then you can do it like :

procedure SomeProc(Sender : TObject);
var
  i : Integer;
begin
  for i := 0 to Self.MDIChildCount - 1 do
   PostMessage(Self.MDIChildren[i].Handle, WM_MY_MESSAGE, wParam, lParam);
end;

--- markus

 

[TimSNL]

Thankyou for your help

To extend this question ...
Is it possible to send these messages out to all computers on my LAN?

Tim

 

[McMerfy]

If you mean WM_ messages then answer is no. Here i have a small client program that allows users to launch my applications, it also checks for updated on server before launching anything AND it recieved commands from server application via socket connection. So when i need to send a WM_ message to clients i send an appropriate command to my loader applications on client computers and it broacasts it on local machine.

--- markus

 

[TimSNL]

PostMessage is working fine if I give it a HWND.
If I try to use the HWND_BROADCAST the message does not seem to make it into the WndProc of my other applications I have running?
Can you email me a sample of code where you have this working? (tim @ snlcomputing .com .au)

Thanks.
Tim