我想撰寫一個以ToolBar與ToolButton結合的物件，程式碼如下：    當我 Compile 時並沒有任何錯誤訊息，可是當我在 RAD 設計階段中，將該物件拉下，要置於 Form 上時即出現 "Error: Control '' has no parent window."，有人可以幫忙看看問題出在那兒嗎？

unit DBBar;    interface    uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ToolWin, ComCtrls;    Type
  TDBBtn = (dbFirst, dbPrior, dbNext, dbLast,
            dbInsert, dbDelete, dbEdit, dbPost, dbSave, dbCancel, dbRefresh);    type
  TDBBar = class(TToolBar)
  private
    { Private declarations }
  protected
    { Protected declarations }
    FButtons: array[TDBBtn] of TToolButton;
  public
    { Public declarations }
    procedure InitButtons;
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  published
    { Published declarations }
  end;    procedure Register;    implementation    procedure Register;
begin
  RegisterComponents('ZERO', [TDBBar]);
end;    { TDBBar }    constructor TDBBar.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  InitButtons;
end;    destructor TDBBar.Destroy;
begin
  inherited Destroy;
end;    procedure TDBBar.InitButtons;
var
  i: TDBBtn;
  Btn: TToolButton;
begin
  for i := Low(FButtons) to High(FButtons) do
  begin
    Btn := TToolButton.Create(Self);
    Btn.Parent := Self;
    FButtons[i] := Btn;
  end;
end;    end.

constructor TDBBar.Create(AOwner: TComponent); begin   inherited Create(AOwner);    Parent := TWinControl(AOwner); //Add InitButtons; end;

你好： 元件繼承自 TWinControl 時，在 Create 後還會呼叫 CreateParams 程序以便完成 Window Handle 的設定。所以如果你在元件內部有需要設定 Parent 的參數則需要在覆載的 CreateParams 程序中設定。下面的範例你參考看看 ^^ 如果有解釋錯誤的請前輩們指正