public virtual string GetErrorMessage(
	CommandLineArgument argument,
	Object? value
)Public Overridable Function GetErrorMessage ( 
	argument As CommandLineArgument,
	value As Object
) As String
Dim instance As ArgumentValidationAttribute
Dim argument As CommandLineArgument
Dim value As Object
Dim returnValue As String
returnValue = instance.GetErrorMessage(argument, 
	value)public:
virtual String^ GetErrorMessage(
	CommandLineArgument^ argument, 
	Object^ value
)Override this method in a derived class to provide a custom error message. Otherwise, it will return a generic error message.