請問一個TCollection的問題 - Delphi K.Top 討論區

發表時間：2004-01-02 21:49:14

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我使用TCollection寫了一個元件，大概如下元件裝來來之後預設的TCollection屬性編輯器一切運作正常但是在設定TBtn的onClick 事件時，就是當我在event那頁，對OnClick按兩下要產生事件時，卻出現了一個錯誤訊息 "Can't Create a Method for a unnamed component" 我本來以為是一定要元件才能產生method，後來今天在william介紹的網站上看到一組免費的元件http://www.droopyeyes.com/default.asp?mode=ShowProduct&ID=3，我下載按裝後發現其中的dibIMageList的寫法架構跟我一樣也是用CollectionItem, 但它的event卻能順利產生。它的itme在按兩下要產生事件時會自動產生一個prodecure 名稱，我的不會。不知是那裏少寫了。

     TBtn = class(TCollectionItem)
  published
    property OnClick: TNotifyEvent read FOnClick write FOnClick stored IsOnClickStored;
end;      TBtns = class(TCollection)
end;      THccBtnCtrl = class(TComponent)
  published
    
    property Items: TBtns read FItems write FItems;  end;

下面是完整的source //////////////////////////////////////////////////////

       TBtn = class(TCollectionItem)
  private
     //   FDisplayName: string;
   FImportedFrom: string;
    FCaption: string;
    FImageIndexUp: Integer;
    FImageIndexDown: Integer;
    FImageIndexOver: Integer;
    FOnClick: TNotifyEvent;
    FDrawRect: TRect;
    FLastState: TLastState;
    FHint: String;
    FTabColor: TColor;
    FIconRect: TRect;
    FCaptionRect: TRect;
    FPaintMode: TPaintMode;
    FPaintState: TPaintState;
    FDown: boolean;
    FOnTranslateImagePath: TDIBTranslateImagePathEvent;
    procedure SetCaption(const Value: string);
    procedure SetImageIndexUp(const Value: Integer);
    function IsOnClickStored: Boolean;
    procedure SetLastState(const Value: TLastState);
    procedure SetTabColor(const Value: TColor);
    procedure ReadTemplateFilename(Reader: TReader);
    procedure WriteTemplateFilename(Writer: TWriter);
  public
    procedure DefineProperties(Filer: TFiler); override;
    constructor Create(Collection: TCollection); override;
    
    property LastState:TLastState read FLastState write SetLastState;        Property PaintMode:TPaintMode  read FPaintMode write FPaintMode;
    
    Property PaintState:TPaintState  read FPaintState write FPaintState;
    
  published
    property DisplayName;
    property Index;
    property Caption: string read FCaption write SetCaption;
    property ImageIndexUp:Integer read FImageIndexUp write SetImageIndexUp;
    property ImageIndexOver:Integer read FImageIndexOver write FImageIndexOver;
    property ImageIndexDown:Integer read FImageIndexDown write FImageIndexDown;
    property OnClick: TNotifyEvent read FOnClick write FOnClick stored IsOnClickStored;
    property DrawRect:TRect read FDrawRect write FDrawRect;
    property IconRect:TRect read FIconRect write FIconRect;
    property CaptionRect:TRect read FCaptionRect write FCaptionRect;
    property Hint:String read FHint write FHint;
    property TabColor:TColor read FTabColor write SetTabColor;        property Down:boolean read FDown write FDown;
  end;          TBtns = class(TCollection)
  private        FOwner: THccBtnCtrl;
    function GetItem(Index: Integer): TBtn;
    procedure SetItem(Index: Integer; const Value: TBtn);
  protected
  public
    constructor Create(AOwner: THccBtnCtrl);
    
    function Add: TBtn;
    procedure Update(Item: TCollectionItem); override;
    Property Owner: THccBtnCtrl Read FOwner;
    function AddTemplate(const GUID: string; const Index: Integer): TBtn;
    
    //--關於陣列屬性default的說明 --
    //The definition of an array property can be followed by the default directive,
    // in which case the array property becomes the default property of the class. For example,
    //
    //type
    //  TStringArray = class
    //  public
    //    property Strings[Index: Integer]: string ...; default;
    //    ...
    //  end;
    //
    //If a class has a default property,
    //you can access that property with the abbreviation object[index],
    //which is equivalent to object.property[index].
    property Btns[Index: Integer]:TBtn read GetItem write SetItem;default;
  end;    --------------------------------------------------------------------------
{ TBtn }    constructor TBtn.Create(Collection: TCollection);
begin
  inherited Create(Collection);
  //  FDisplayName := inherited GetDisplayName;
  FLastState:=lsMouseUp;
  ImageIndexUp:=index;
  ImageIndexOver:=-1;
  ImageIndexDown:=-1;
  FTabColor:=clWhite;
  caption:='檔案管理';
  FDown:=false;    end;    procedure TBtn.DefineProperties(Filer: TFiler);
begin
  inherited;
  Filer.DefineProperty('TemplateFilename', ReadTemplateFilename,
    WriteTemplateFilename, (FImportedFrom <> ''));
end;    function TBtn.IsOnClickStored: Boolean;
begin    end;    procedure TBtn.ReadTemplateFilename(Reader: TReader);
begin
 FImportedFrom := Reader.ReadString;
end;    procedure TBtn.SetCaption(const Value: string);
begin
  FCaption := Value;
end;    procedure TBtn.SetImageIndexUp(const Value: Integer);
begin
  FImageIndexUp := Value;
end;    procedure TBtn.SetLastState(const Value: TLastState);
begin
  FLastState := Value;
end;    procedure TBtn.SetTabColor(const Value: TColor);
begin
  FTabColor := Value;
end;    procedure TBtn.WriteTemplateFilename(Writer: TWriter);
begin
  Writer.WriteString(FImportedFrom);
end;    { TBtns }    function TBtns.Add: TBtn;
begin
  Result := TBtn(inherited Add);
end;    function TBtns.AddTemplate(const GUID: string; const Index: Integer): TBtn;
var
  I, Position: Integer;
  SearchString: string;
begin
  Position := -1;
  SearchString := GUID   ':'   IntToStr(Index);      for I := 0 to Count - 1 do 
  begin
    if Btns[I].FImportedFrom = SearchString then
    begin
      Position := I;
      break;
    end;
  end;      if Position > -1 then
    Result := Btns[Position]
  else
  begin
    Result := Add;
    Result.FImportedFrom := GUID   ':'   IntToStr(Index);
  end;
end;    constructor TBtns.Create(AOwner: THccBtnCtrl);
begin
  inherited Create(TBtn);
  FOwner := AOwner;    end;    function TBtns.GetItem(Index: Integer): TBtn;
begin
  Result:=TBtn(Items[index]);
end;    procedure TBtns.SetItem(Index: Integer; const Value: TBtn);
begin
  Items[index]:= Value;
end;    procedure TBtns.Update(Item: TCollectionItem);
begin
  inherited;
  Owner.DoChange;
end;