So I decided to give VCL styles in XE7.

Changing my style in the IDE Project, Options window from "Windows" to any 
other results in the initial form in my app misbehaving. The window state
seems weird, and the minimize/maximize/close buttons don't work.  And the 
TMainMenu "fights" with the TToolbar for visibility.

I have to double click the title bar to resize the form before the form 
starts behaving properly.

It seems that my code setting TForm.WindowState to the state when the 
program was previously closed is causing some problems. Before exploring 
this further, I thought I'd ask are there any known problems of this sort 
with styles?

Robert Frank wrote:

> Do you have any further information or can you point me towards any
> documentation on this issue?

You are doing it in events, I see.
It's not necessarily going to work fine then, we do it like this here:

// Interface section

TBaseForm = class(TForm)
public
   constructor Create(AOwner : TComponent);
end;

// Implementation section

constructor TBaseForm .Create(AOwner : TComponent);
const
   ValueNotFound = Low(Integer);
var
   R: TRect;
   Dimension: Integer;
begin
   inherited Create(AOwner);

   if BorderStyle in [bsSizeable, bsSizeToolWin] then
   begin
     // To be able to restore on another monitor than the "default"
     // we must use this value on the property.
     // See TCustomForm.SetWindowToMonitor for details
     DefaultMonitor := dmDesktop;

     R := GetSavedRect;

     if (R.Left <> ValueNotFound) then
     begin
       Position := poDesigned;
       WindowMonitor := Screen.MonitorFromRect(R);

       if R.Right - R.Left > WindowMonitor.Width then
         R.Right := R.Left + WindowMonitor.Width;

       if R.Bottom - R.Top > WindowMonitor.Height then
         R.Bottom := R.Top + WindowMonitor.Height;

       Dimension := R.Right - R.Left;
       if R.Right > WindowMonitor.Left + WindowMonitor.Width then
         R.Left := WindowMonitor.Left + WindowMonitor.Width - Dimension;
       if R.Left < WindowMonitor.Left then
         R.Left := WindowMonitor.Left;
       R.Right := R.Left + Dimension;

       Dimension := R.Bottom - R.Top;
       if R.Bottom > WindowMonitor.Top + WindowMonitor.Height then
         R.Top := WindowMonitor.Top + WindowMonitor.Height - Dimension;
       if R.Top < WindowMonitor.Top then
         R.Top := WindowMonitor.Top;
       R.Bottom := R.Top + Dimension;

       SetBounds(R.Left, R.Top, R.Right - R.Left, R.Bottom - R.Top);
     end;

     if MustRestoreMaximized then
       WindowState := wsMaximized;
   end;
end;

GetSavedRect is for you to write and must return a TRect that has 
Low(Integer) in its values if nothing was ever saved.
MustRestoreMaximized is for you to implement as well and should return a 
Boolean set to True if the form was maximized.

Here, this works well.

>Robert Frank wrote:
>
>> It seems that my code setting TForm.WindowState to the state when the
>> program was previously closed is causing some problems. Before exploring
>> this further, I thought I'd ask are there any known problems of this sort
>> with styles?
>
>Not just with styles, but with newer versions of Delphi / Windows as well.
>Basically, changing the window state in the creator is not really
>advisable anymore, but you'd have to show us your code to be sure.

Thanks, Olivier.

My code is simple:

Form1.WindowState := wsMaximized;

I can avoid that.

But, if a form isn't maximized, I want to have it's size and position 
persistent between uses.  it appears that even changing the form's .Left, 
..Width, .Height, or .Width can cause problems.

Even making the changes later (in FormShow or FormActivate) seems to cause 
some problems.

Do you have any further information or can you point me towards any 
documentation on this issue?

Thanks!

Robert Frank wrote:

> It seems that my code setting TForm.WindowState to the state when the
> program was previously closed is causing some problems. Before exploring
> this further, I thought I'd ask are there any known problems of this sort
> with styles?

Not just with styles, but with newer versions of Delphi / Windows as well.
Basically, changing the window state in the creator is not really 
advisable anymore, but you'd have to show us your code to be sure.