自定义组件释放时出错。

[tp机器猫]

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.

unit PageCtrolEx;

interface

uses
  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;

implementation


Procedure 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.

[s11ss]

destructor TPageCtrolEx.Destroy;
里头的
for j := 0 to ControlCount - 1 do
应当改作
for j := ControlCount - 1 downto 0 do

[kaikai_kk]

Add时没有添加到FPageList

[tp机器猫]

找到了。用removecontrol方法删除。但是在设计时删除子组件时还是会报错。运行时没问题