Fórum Invalid class Typecast #268851

  TShowFieldsItem = Class(TCollectionItem)
  private
    FCaption: String;
    FFieldName: String;
    procedure SetCaption(const Value: String);
    procedure SetFieldName(const Value: String);
  protected
    function GetDisplayName : string; override;
  public
    constructor Create(Collection : TCollection); override;
    destructor Destroy; override;
  published
    property Caption : String read FCaption write SetCaption;
    property FieldName : String read FFieldName write SetFieldName;
  end;

  TShowFields = Class(TCollection)
  private
    FOwner : TComponent;
    function GetItems(Index: integer): TShowFieldsItem;
    procedure SetItems(Index: integer; const Value: TShowFieldsItem);
  protected
    function GetOwner : TPersistent; override;
  public
    constructor Create(AOwner : TComponent);
    function Add : TShowFieldsItem;
    function Insert(Index : integer) : TShowFieldsItem;
    property Items[Index : integer] : TShowFieldsItem read GetItems write SetItems;
  end;
  TCustomProperty = class (TStringProperty)
  public
    function GetAttributes: TPropertyAttributes; override;
  end;

  TSearchTableProperty = class (TCustomProperty)
  public
    procedure GetValues(Proc: TGetStrProc); override;
  end;

  TSearchFieldProperty = class (TCustomProperty)
  public
    procedure GetValues(Proc: TGetStrProc); override;
  end;

procedure Register;
begin
  RegisterComponents(´Renato´, [TSearch]);
  RegisterPropertyEditor (TypeInfo(String), TSearch, ´TableName´, TSearchTableProperty);
  RegisterPropertyEditor (TypeInfo(String), TShowFieldsItem, ´FieldName´, TSearchFieldProperty);
end;