Another SetWindowsHookEx problem.  Setting ThreadID to 0 in Delphi 7 but getting an Application Hook instead

Hello  kfoster11 , there may be a better way to do this, I would think that the menus will get when they loose the keyboard focus, and then close, because they also vanish if you do NOT click anything, and just change focus (by keyboard). You may look at this EE Question, for some code to do this -

https://www.experts-exchange.com/Programming/Programming_Languages/Delphi/Q_21718165.html

I have plenty of examples for doing Key Hooks, the reason your code does not work is because this DLL is loaded into most of the other processes and in the other processes the HookMouse procedure is NOT called, so in those DLL loads the  TheComponentHandle  is never loaded into the variable, , you will need  Map File memory container to have this TheComponentHandle availible to all instances of the DLL

here is some code for a Mouse Hook Library, it has two exported functions, StartHook and StopHook,. . .
By the way - - Your "ComponentHandles" StringList may Not work to store window handles be cause it is NOT a shared memory, if you need to have an array of Handles, I would think you will need to do it in a Memory Mapped file, so all the DLLs can read it, , I wonder why you use stdcall  in your HookMouse procedure ?



library MouseHk;

uses
  Messages, Windows, SysUtils;

{$R *.RES}



const
memFileName = 'eJ7Lc+2Yk';

var
Hooked: Boolean = False;
hMouseHook, hMemFile: THandle;
pFormHnd: PDWORD = nil;



function HkFunc(Code, wParam: Integer; var MouseStrut: TMOUSEHOOKSTRUCT): Integer; stdcall;
begin
Result:=CallNextHookEx(0, Code, wParam, Integer(@MouseStrut));
if pFormHnd = nil then Exit;
if (Code = HC_ACTION)then
  if (wParam = WM_LBUTTONDOWN) or (WM_NCLBUTTONDOWN = wParam) then
    PostMessage(pFormHnd^, WM_CLOSE, 0, 0);

end;



function StartHook(hForm: THandle): Integer;
begin
Result := 0;
if Hooked then
  begin
  Result := 1;
  Exit;
  end;
if not IsWindow(hForm) then
  begin
  Result := 2;
  Exit;
  end;
hMouseHook := SetWindowsHookEx(WH_MOUSE, @HkFunc, hInstance, 0);
if hMouseHook = 0 then
  Result := 3 else
  begin
  hMemFile := CreateFileMapping(MAXDWORD, nil, PAGE_READWRITE,0,
                SizeOf(THandle), memFileName);
  pFormHnd := MapViewOfFile(hMemFile, FILE_MAP_WRITE, 0, 0, 0);
  if pFormHnd = nil then
    begin
    Result := 4;
    UnhookWindowsHookEx(hMouseHook);
    Exit;
    end else
    pFormHnd^ := hForm;

  Hooked := True;
  end;
end;


function StopHook: Boolean;
begin
if Hooked and (hMouseHook <> 0) then
  Result := UnhookWindowsHookEx(hMouseHook) else
  Result := True;
Hooked := False;
if pFormHnd <> nil then
  begin
  UnmapViewOfFile(pFormHnd);
  pFormHnd := nil;
  end;
CloseHandle(hMemFile);
end;


procedure EntryProc(dwReason : DWORD);
begin
if (dwReason = Dll_Process_Detach) then
 begin
 if hMouseHook <> 0 then
   UnhookWindowsHookEx(hMouseHook);
 if pFormHnd <> nil then
   UnmapViewOfFile(pFormHnd);
 CloseHandle(hMemFile);
 end;
end;


exports
  StartHook,
  StopHook;

begin
DLLProc := @EntryProc;
hMemFile := OpenFileMapping(FILE_MAP_WRITE, False, memFileName);
  if hMemFile <> 0 then
    pFormHnd := MapViewOfFile(hMemFile, FILE_MAP_WRITE, 0, 0, 0);
end.
 

code in Form to use DLL -




procedure TForm1.but_MouseHkClick(Sender: TObject);
var
hLibb: THandle;
StartHook: function(hForm: THandle): Integer;
begin
hLibb := LoadLibrary('MouseHk.dll');
if hLibb = 0 then
  begin
  Showmessage('ERROR - Library did NOT Load');
  Exit;
  end;

@StartHook := GetProcAddress(hLibb, 'StartHook');
if @StartHook = nil then
  begin
  ShowMessage('StartHook was not located');
  FreeLibrary(hLibb);
  Exit;
  end;
if StartHook(Handle) <> 0 then
  begin
  Showmessage('ERROR - StartHook Failed');
  end;

end;