完全なソースコードはここにあります: http ://www.eyeClaxton.com/download/delphi/SkinProject.zip
「キャプションまたはボーダー」のないスキンフォームを作成しようとしていますが、システムメニュー(つまり、移動、最小化、最大化、復元、サイズ)へのフルアクセスが残っています。WS_SYSMENU、WS_MAXIMIZEBOX、WS_MINIMIZEBOXを使用してCreateParamsプロシージャをオーバーライドすることにより、すべてのメニュー項目を実現できます。WS_SIZEBOXを使用すると、メニューの[サイズ]コマンドにアクセスできますが、不要な境界線が描画されます。上記のリンクに完全な(Delphi 7)の例を含めました。さらに詳しい情報が必要な場合は、お気軽にお問い合わせください。
procedure TMainFrm.CreateParams(var Params: TCreateParams);
begin
  FormStyle := fsNormal;
  try
    if (BorderIcons <> []) then BorderIcons := [];
    if (BorderStyle <> bsNone) then BorderStyle := bsNone;
    inherited CreateParams(Params);
    Params.ExStyle := (Params.ExStyle and (not WS_EX_WINDOWEDGE)
      and (not WS_EX_STATICEDGE) and (not WS_EX_DLGMODALFRAME) and (not WS_EX_CLIENTEDGE));
    Params.Style := (Params.Style and (not WS_CAPTION) and (not DS_MODALFRAME)
      and (not WS_DLGFRAME) and (not WS_THICKFRAME));
    Params.Style := (Params.Style or WS_SYSMENU or WS_MAXIMIZEBOX or WS_MINIMIZEBOX or WS_SIZEBOX);
  finally
    Position := poScreenCenter;
  end;
end;
解決:
unit WndProcUnit;
interface
uses
  Windows, Messages, Classes, Controls, Forms, SysUtils;
type
  EWndProc = class(Exception);
  TWndProcMessages = class(TComponent)
  private
    { Private declarations }
    FOwnerWndProc: TFarProc;
    FNewWndProc: TFarProc;
  protected
    { Protected declarations }
    procedure WndProc(var theMessage: TMessage); virtual;
  public
    { Public declarations }
    constructor Create(theOwner: TComponent); override;
    destructor Destroy(); override;
    procedure DefaultHandler(var theMessage); override;
  end;
  TWndProc = class(TWndProcMessages)
  private
    { Private declarations }
  protected
    { Protected declarations }
    procedure Loaded(); override;
  public
    { Public declarations }
    constructor Create(theOwner: TComponent); override;
    destructor Destroy(); override;
  published
    { Published declarations }
  end;
implementation
{ TWndProcMessages }
constructor TWndProcMessages.Create(theOwner: TComponent);
var
  X, I: Integer;
begin
  inherited Create(theOwner);
  if (not (Owner is TForm)) then
    raise EWndProc.Create('TWndProc parent must be a form!');
  I := 0;
  for X := 0 to (Owner.ComponentCount - 1) do
  begin
    if (Owner.Components[X] is TWndProc) then Inc(I);
    if (I > 1) then Break;
  end;
  if (I > 1) then
  begin
    raise EWndProc.Create('The form already contains a TWndProc!');
  end
  else begin
    FOwnerWndProc := TFarProc(GetWindowLong((Owner as TForm).Handle, GWL_WNDPROC));
    FNewWndProc := Classes.MakeObjectInstance(WndProc);
    if (not (csDesigning in ComponentState)) then
      SetWindowLong((Owner as TForm).Handle, GWL_WNDPROC, LongInt(FNewWndProc));
  end;
end;
destructor TWndProcMessages.Destroy();
begin
  if Assigned(FNewWndProc) then
  try
    Classes.FreeObjectInstance(FNewWndProc);
  finally
    if (Pointer(FNewWndProc) <> nil) then Pointer(FNewWndProc) := nil;
  end;
  if Assigned(FOwnerWndProc) then Pointer(FOwnerWndProc) := nil;
  inherited Destroy();
end;
procedure TWndProcMessages.DefaultHandler(var theMessage);
begin
  if ((Owner as TForm).Handle <> 0) then
  begin
    case TMessage(theMessage).Msg of
      WM_DESTROY:
        SetWindowLong((Owner as TForm).Handle, GWL_WNDPROC, LongInt(FOwnerWndProc));
      WM_INITMENU:
        EnableMenuItem(TMessage(theMessage).WParam, SC_SIZE, MF_BYCOMMAND or MF_ENABLED);
    else
      with TMessage(theMessage) do
        Result := CallWindowProc(FOwnerWndProc, (Owner as TForm).Handle, Msg, WParam, LParam);
    end;
  end
  else
    inherited DefaultHandler(theMessage);
end;
procedure TWndProcMessages.WndProc(var theMessage: TMessage);
begin
  Dispatch(theMessage);
end;
{ TWndProc }
constructor TWndProc.Create(theOwner: TComponent);
begin
  inherited Create(theOwner);
end;
destructor TWndProc.Destroy();
begin
  inherited Destroy();
end;
procedure TWndProc.Loaded();
begin
  inherited Loaded();
  if (not (csDesigning in ComponentState)) then
    GetSystemMenu((Owner as TForm).Handle, False);
end;
end.
完全な「更新された」ソースコードはここにあります: http ://www.eyeClaxton.com/download/delphi/SkinProject.zip