自定义组件释放时出错。
刚开始学写组件。
下面的代码，写好安装后。放进一个窗口中。先执行几次add函数。然后执行delete（一次或多次），然后关闭窗口。
这时报错。好像是释放问题。该怎么解决呀.

Delphi(Pascal) code

unit PageCtrolEx;interfaceuses  SysUtils,Classes,Controls,ExtCtrls,Graphics,GraphUtil  ,windows;type  TPageCtrolEx=class;  TTabSheetEX= class(TCustomControl)  private    FGradientStart,FGradientEnd:TColor;    FDirection:TGradientDirection;    FpageCtrl:TPageCtrolEx;  protected    procedure SetParent(AParent: TWinControl); override;  public     constructor create(Aowner:TComponent);override;     destructor Destroy;override;  published     property Caption;//     property align;  end;  TPageCtrolEx = class(TCustomControl)  private     FPageList:TList;     function GetPageCount:Integer;     function GetPages(Index: Integer): TTabSheetEX;     procedure Resize; override;    { Private declarations }  protected    procedure Paint;override;    { Protected declarations }  public    constructor create(Aowner:TComponent);override;    destructor Destroy;override;    function Add:TTabSheetEX;    procedure Delete(AIndex:integer);    property PageCount:Integer read GetPageCount;    property Pages[Index: Integer]: TTabSheetEX read GetPages;    { Public declarations }  published    property color;    { Published declarations }  end;Procedure Register;implementationProcedure Register;Begin  RegisterComponents( 'test', [ TPageCtrolEx ] );End;{ TPageCtrolEx }function TPageCtrolEx.Add: TTabSheetEX;begin  Result:=TTabSheetEX.Create(Self);  OutputDebugString(PChar(IntToStr(FPageList.Count)));end;constructor TPageCtrolEx.create(Aowner: TComponent);begin  inherited Create(Aowner);  FPageList:=TList.Create;end;procedure TPageCtrolEx.Delete(AIndex: integer);var  I: Integer;begin  if AIndex<FPageList.Count then    begin      for I := 0 to ControlCount - 1 do        begin          if TTabSheetEX(FPageList.Items[AIndex])=Controls[I] then             begin               (Controls[I] as TTabSheetEX).free;               Break;             end;        end;      FPageList.Delete(AIndex);    end;end;destructor TPageCtrolEx.Destroy;var  I: Integer;  j: Integer;begin//  for I := 0 to FPageList.Count - 1 do//    begin//        for j := 0 to ControlCount - 1 do//          begin//            if Controls[j]=TTabSheetEX(FPageList.Items[I]) then//            begin//               Controls[j].Free;//               Continue;//            end;//          end;//    end;//  FPageList.Free;  inherited;end;function TPageCtrolEx.GetPageCount: Integer;begin  Result:=FPageList.Count;end;function TPageCtrolEx.GetPages(Index: Integer): TTabSheetEX;begin  // TODO -cMM: TPageCtrolEx.GetPages default body inserted  Result := TTabSheetEX(FPageList.Items[index]);end;procedure TPageCtrolEx.Paint;var  I: Integer;  Arect:TRect;begin  inherited;  arect:=Bounds(0,0,0,0);  for I := 0 to FPageList.Count-1 do    begin      Arect.Left:=Arect.Right+2;      Arect.Top:=1;      Arect.Right:=Arect.Left+50;      Arect.Bottom:=24;      Canvas.Brush.Color:=clWhite;      Canvas.FillRect(Arect);      Canvas.TextOut(Arect.Left+2,3,TTabSheetEX(FPageList.Items[I]).Caption);      TTabSheetEX(FPageList.Items[I]).DrawBackGround ;    end;end;procedure TPageCtrolEx.Resize;var  I: Integer;begin  inherited;  for I := 0 to FPageList.Count - 1 do    begin      TTabSheetEX(FPageList.Items[I]).Height:=Height-24;    end;end;{ TTabSheetEX }constructor TTabSheetEX.create(Aowner: TComponent);begin  ControlStyle := [csAcceptsControls];  inherited Create(Aowner);               //.Owner  FpageCtrl:=TPageCtrolEx(Aowner);  Parent:=FpageCtrl;  Height:=FpageCtrl.Height-24;  //align:=alBottom;  Name:='Tab'+inttostr(FpageCtrl.FPageList.Count);  FpageCtrl.FPageList.Add(Self);end;destructor TTabSheetEX.Destroy;begin   inherited;end;procedure TTabSheetEX.SetParent(AParent: TWinControl);begin  if AParent <>FpageCtrl then Exit;  inherited;end;end. 
 

[解决办法]
destructor TPageCtrolEx.Destroy;
里头的
for j := 0 to ControlCount - 1 do
应当改作
for j := ControlCount - 1 downto 0 do
[解决办法]
Add时没有添加到FPageList