How to determine if a property has inherited from a particular class (Views: 29)
Problem/Question/Abstract: How can I propogate through an object's published properties and extract an actual class reference in order to perform operations like: if GiveProperty is TSomeObjectType then do something? Answer: function GetFontProp(anObj: TObject): TFont; var PInfo: PPropInfo; begin {Try to get a pointer to the property information for a property with the name 'Font'. TObject.ClassInfo returns a pointer to the RTTI table, which we need to pass to GetPropInfo} PInfo := GetPropInfo(anObj.ClassInfo, 'font'); Result := nil; if PInfo <> nil then {found a property with this name, check if it has the correct type} if (PInfo^.Proptype^.Kind = tkClass) and GetTypeData(PInfo^.Proptype^)^.ClassType.InheritsFrom(TFont) then Result := TFont(GetOrdProp(anObj, PInfo)); end; |