[SOLVED] EnumWindows doesnt Finish

[Cliff48]

The Following code used to work, but now EnumWindows never finishes  /   returns.

Code: [Select]

function AllWindows(hW: THandle; List: Integer): Boolean; stdcall;
var
  l:      LongInt;
  found:  Boolean = false;
  wCaption:     String[255];
begin
  Result := True;
  l := SendMessage(hW, WM_GETTEXT, 254, LongInt(@wCaption[1]));
    if l > 0 then begin
      wCaption[0] := char(l);
      FormEnum.cb1.Items.add(wCaption);
    end;
  showMessage(IntToHex(hW, 8) + ' ' + IntToStr(l));
end;
   
 procedure TFormEnum.FormCreate(Sender: TObject);
begin
  ShowMessage('Enum Windows');
  enumWindows(@AllWindows, 0);
  showmessage('Pause');
end;       

EnumW calls the AllWindows Function many times, but after it is done, the system is left in a loop and ShowMessage('Pause') is never executed.

This is a Function I have in a working program and the above was created to isolate/demonstrate the problem I'm having.
One thing different, is that the working program is compiled with
{$mode Objfpc}{$H+}   but to compile the above I had to change to:  {$mode Delphi}{$H+}  which I dont understand why.

I assume I have done something silly, but I cant see it.  Any help would be appreciated.                         

[Cliff48]

I added

    if IsWindowVisible(hW) then 

before the SendMessage(hW, WM_GETTEXT .........

Obviously Windows hangs waiting for a response from a non-visible window.

Still curious as to why I needed to compile in Delphi mode tho.

[typo]

You need to replace mode ObjFPC by mode Delphi:

Code: [Select]

//{$mode objfpc}
{$mode delphi}{$H+}


[Cliff48]

You need to replace mode ObjFPC by mode Delphi:

Code: [Select]

//{$mode objfpc}
{$mode delphi}{$H+}


Can someone explain why i had to change ... and why it compiled with objfpc previously?