The atomized string or the existing string if one already exists in the NameTable. If len is zero, String.Empty is returned.
Type Reason IndexOutOfRangeException start < 0.
- or -
start >= key.Length.
- or -
len > key.Length - start.
The above conditions do not cause an exception to be thrown if len = 0.
ArgumentOutOfRangeException len < 0.
For more information on atomized strings, see System.Xml.NameTable.