.NET provides a hierarchy of exception classes ultimately derived from theException base class. However, if none of the predefined exceptions meet your needs, you can create your own exception class by deriving from theException class.

When creating your own exceptions, end the class name of the user-defined exception with the word "Exception", and implement the three common constructors, as shown in the following example. The example defines a new exception class namedEmployeeListNotFoundException. The class is derived from theException base class and includes three constructors.

using System;public class EmployeeListNotFoundException : Exception{    public EmployeeListNotFoundException()    {    }    public EmployeeListNotFoundException(string message)        : base(message)    {    }    public EmployeeListNotFoundException(string message, Exception inner)        : base(message, inner)    {    }}

Public Class EmployeeListNotFoundException    Inherits Exception    Public Sub New()    End Sub    Public Sub New(message As String)        MyBase.New(message)    End Sub    Public Sub New(message As String, inner As Exception)        MyBase.New(message, inner)    End SubEnd Class

See also

• Exceptions