private string GetCaption(string[] keys)
{
var all = GetPropertyValuesAsStrings();
List<string> list = new List<string>();
foreach (var values in keys.Select(i => all[i]))
{
if (values.Count != 0 &&
values.Contains("Unknown") == false)
list.AddRange(values);
}
if (list.Count == 0)
return "Unknown";
return String.Join(" - ", list.ToArray());
}