This exception indicates that a user attempted to use a method when the object was not in an appropriate state. For example, this exception is thrown if you attempt to write data with a System.Xml.XmlTextWriter that is already closed. public class InvalidOperationException : SystemException { // Public Constructors public InvalidOperationException ( ); public InvalidOperationException (string message ); public InvalidOperationException (string message , Exception innerException ); // Protected Constructors protected InvalidOperationException (System.Runtime.Serialization.SerializationInfo info , System.Runtime.Serialization.StreamingContext context ); } HierarchyObject Exception(System.Runtime.Serialization.ISerializable) SystemException InvalidOperationException SubclassesObjectDisposedException , System.Net.{ProtocolViolationException , WebException} |