This is the base class for COM interop and SEH (Structured Exception Handler) exceptions. public class ExternalException : SystemException { // Public Constructors public ExternalException ( ); public ExternalException (string message ); public ExternalException (string message , Exception inner ); public ExternalException (string message , int errorCode ); // Protected Constructors protected ExternalException (System.Runtime.Serialization.SerializationInfo info , System.Runtime.Serialization.StreamingContext context ); // Public Instance Properties public virtual int ErrorCode {get; } } HierarchySystem.Object System.Exception(System.Runtime.Serialization.ISerializable) System.SystemException ExternalException SubclassesCOMException , SEHException |