Modificar uma propriedade

unit uStringProperty;

interface

uses
  DesignEditors, DesignIntf, SysUtils, Dialogs, StdCtrls;

type
  TStringProperty = class(TPropertyEditor)
  public
    function GetAttributes: TPropertyAttributes; override;
    function GetValue: string; override;
    procedure Edit; override;
    procedure SetValue(const Value: string); override;
  end;

implementation

uses
  uFrmEditor, Controls;

{ TEditorSqlProperty }

procedure TStringProperty.Edit;
begin
  inherited Edit;

  with GetComponent(0) as TCustomLabel do
    with TFrmEditor.Create(nil) do
    try
      mmEditor.Lines.Text := Caption;
      ShowModal;
      if ModalResult = mrOk then
      begin
        Caption := mmEditor.Lines.Text;
      end;
    finally
      Free;
    end;
end;

function TStringProperty.GetAttributes: TPropertyAttributes;
begin
  Result := [paDialog];
end;

function TStringProperty.GetValue: string;
begin
  Result := (GetComponent(0) as TCustomLabel).Caption;
end;

procedure TStringProperty.SetValue(const Value: string);
begin
  if Trim(Value) = (GetComponent(0) as TCustomLabel).Caption then
    Exit;

  TCustomLabel(GetComponent(0)).Caption := Trim(Value);
  Designer.Modified;
end;

end.

    RegisterPropertyEditor(TypeInfo(String), TCustomControl, ´Caption´, TStringProperty);