object - забудьте. Это старые объекты из TurboPascal-я.
Пример на классах:
| Код | type
TBase = class
private
FField1: Integer;
FField2: String;
public
constructor Create(const AField1: Integer; const AField2: String); virtual;
property Field1: Integer read FField1;
property Field2: String read FField2;
end;
TChild1 = class(TBase)
private
FField3: Extended;
FField4: Boolean;
public
constructor Create(const AField1: Integer; const AField2: String; const AField3: Extended; const AField4: Boolean); reintroduce;
property Field3: Extended read FField3;
property Field4: Boolean read FField4;
end;
TChild2 = class(TBase)
private
FField5: Cardinal;
FField6: Byte;
public
constructor Create(const AField1: Integer; const AField2: String; const AField5: Cardinal; const AField6: Byte); reintroduce;
property Field5: Cardinal read FField5;
property Field6: Byte read FField6;
end;
constructor TBase.Create(const AField1: Integer; const AField2: String);
begin
inherited Create;
FField1 := AField1;
FField2 := AField2;
end;
constructor TChild1.Create(const AField1: Integer; const AField2: String; const AField3: Extended; const AField4: Boolean);
begin
inherited Create(AField1, AField2);
FField3 := AField3;
FField4 := AField4;
end;
constructor TChild2.Create(const AField1: Integer; const AField2: String; const AField5: Cardinal; const AField6: Byte);
begin
inherited Create(AField1, AField2);
FField5 := AField5;
FField6 := AField6;
end;
var
Obj: array of TBase;
begin
SetLength(Obj, 3);
Obj[0] := TBase.Create(1, '1');
Obj[1] := TChild1.Create(2, '2', 3.4, False);
Obj[2] := TChild2.Create(3, '3', 9, 0);
Tag := Obj[0].Field1 + Obj[1].Field1 + Obj[3].Field1;
if Obj[0] is TChild2 then
Tag := Tag + TChild2(Obj[0]).Field5;
if Obj[1] is TChild2 then
Tag := Tag + TChild2(Obj[1]).Field5;
if Obj[2] is TChild2 then
Tag := Tag + TChild2(Obj[2]).Field5;
FreeAndNil(Obj[2]);
FreeAndNil(Obj[1]);
FreeAndNil(Obj[0]);
end; |
(писал на коленке, могут быть опечатки)
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