Title: Hide MDIChild form
One of the ways for MDIChild form hiding is WinAPI ShowWindow and SetWindowPos functions.
Hide1Click procedure hides the form and Show1Click procedure shows this form.
Don't forget to remove line
Application.CreateForm(TForm2, Form2) from project file and line
var Form2: TForm2 from unit2.pas file.
var
ChildForm: TForm;
...
procedure TForm1.New1Click(Sender: TObject);
begin
if not Assigned(ChildForm) then
begin
ChildForm:=TForm2.Create(Application);
ChildForm.Caption:='ChildForm';
end;
end;
procedure TForm1.Hide1Click(Sender: TObject);
begin
if Assigned(ChildForm) then
ShowWindow(ChildForm.Handle, SW_HIDE);
end;
procedure TForm1.Show1Click(Sender: TObject);
begin
if Assigned(ChildForm) then
SetWindowPos(ChildForm.Handle, HWND_TOP, 0, 0, 0, 0,
SWP_NOSIZE or SWP_NOMOVE or SWP_SHOWWINDOW);
end;