Handler of a mdi child window 1

[tolemac]

Hi !
Here is my problem...
I want to send some messages to a child window from a MDI application. To do this I need the handler of that child window. I've tried to use FindWindow, but FindWindow is searching only through top level windows. I have the name of the MDI application and the name of the child window from that application. What I need is the handler of the child window to send it some messages.

Can anyone help me with some ideas and maybe some code examples?

Thanks.

 

[mikca]

Hi Tolemac
You can scan all open child forms like

var
Loop : integer;

begin
for Loop := 0 to ChildCount - 1 do begin
if Children[Loop] is TMessageForm then begin
PostMessage(Children[Loop].Handle, ..)
or TMessageForm(Children[Loop]).AProperty := NewValue;

end;
end;
end;

 

[whosrdaddy]

Hi,

use Findwindow to find top level window of the MDI app and use that handle in the FindwindowEx API function to search it's child windows. Just to give you a small example how to do this :

hwnd_TOP:=Findwindow(PChar(Appname),nil); // look for APP
if hwndTOP <> 0 then
begin
hwnd_MDI:=FindWindowEx(hwnd_TOP,0,PChar(STR_MDICLIENT),nil); // get mdiclient window area
if hwnd_MDI <> 0 then
begin
hwnd_CH:=FindWindowEx(hwnd_MDI,0,PChar(STR_WFCHANNEL),nil); // find a channel window
if hwnd_CH <> 0 then
begin
SendMessage(hwnd_CH,WM_SYSCOMMAND,SC_MAXIMIZE,0); // send maximize system command , this will maximize all channel windows
end;
end;

I use this code in a to maximize a certain MDI window in a certain app. Just use Winsight or Spy++ to find the names of the windows you want to manipulate.

greetings,

http://www.damovo.com

 

[tolemac]

Hi,
For what I need to do, whosrdaddy's solution is the best one. Thanks whosrdaddy.
Anyway mikca thanks for trying to help me.

I have one more question. Now that I have the child window handle, how can I get its position on the screen? I want to send a mouse click event somewhere in that window and I need the window's coordinates.

 

[tolemac]

Hi again!
I have found a solution to my problem. I've used GetWindowPlacement API function to get the location of the window.

I've did something like this:

var appPl,chPl:TWindowPlacement;
appRect,chRect:TRect;
winX, winY:Integer;
...

appPl.length:=SizeOf(TWindowPlacement);
GetWindowPlacement(hwnd_TOP,@appPl);
appRect:=appPl.rcNormalPosition;

chPl.length:=SizeOf(TWindowPlacement);
GetWindowPlacement(hwnd_CH,@chPl);
chRect:=chPl.rcNormalPosition;

winX:=appRect.Left+chRect.Left;
winY:=appRect.Top+chRect.Top;