function OleVarToString(const OleValue: OleVariant): string;
{$J+}const NotSetStr: string = ''; {$J-}
begin
if NotSetStr = '' then
NotSetStr := LoadMyResString(IDS_NotSet); //NotSetStr是字符串[没有设置]
if VarIsNull(OleValue) then Result := NotSetStr
else Result := String(OleValue);
end;