类型变化的开放数组参数

procedure ShowMsg(const fmtStr:string; const params: array of const);
begin
  ShowMessageFmt(fmtStr,params);
end;

function SumAll(const Args: array of const): Extended;
var
  I: Integer;
begin
  Result := 0;
  for I := Low(Args) to High(Args) do
  case Args[I].VType of
    vtInteger: Result :=
      Result + Args[I].VInteger;
    vtBoolean:
      if Args[I].VBoolean then
        Result := Result + 1;
    vtChar:
      Result := Result + Ord(Args[I].VChar);
    vtExtended:
      Result := Result + Args[I].VExtended^;
    vtString, vtAnsiString:
      Result := Result + StrToIntDef((Args[I].VString^), 0);
    vtWideChar:
      Result := Result + Ord(Args[I].VWideChar);
    vtCurrency:
      Result := Result + Args[I].VCurrency^;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  i: Integer;
  d: Double;
  e: Extended;
begin
  i := 99;
  d := 10.8;
  e := SumAll([1,2,3,4,5]);
  ShowMessageFmt('%f',[e]);

  e := SumAll([i,2.5,3,d,5]);
  ShowMessageFmt('%f',[e]);

  ShowMsg('Integer:%d, Double:%f',[i,d]);
end;