Today I had a little problem with component mapping and the attributes. And It has something to do with the fact that all my objects use interfaces.

I had this in my MspResult class.

<NHibernate.Mapping.Attributes.ComponentProperty(componenttype:=GetType(Littlexyz))> _
        Public Overridable Property Littlexyz() As Interfaces.ILittleXyz Implements IMspResult.Littlexyz
            Get
                _Log.LogDebug("Property Littlexyz - returning _Littlexyz")
                Return _littlexyz
            End Get
            Set(ByVal Value As Interfaces.ILittleXyz)
                _Log.LogDebug("Property Littlexyz - setting _Littlexyz")
                _littlexyz = Value
            End Set
        End Property

And this in the Littlexyz class.

<NHibernate.Mapping.Attributes.Component())> _
    Public Class Littlexyz
        Implements ILittleXyz

#Region " Private members "
        ''' <summary>
        ''' A local variable called _x of type Decimal
        ''' </summary>
        ''' <remarks>Has Property X</remarks>
        Private _x As Decimal

Which gave me this error in nhibernate

NHibernate.MappingException: Problem trying to set property type by reflection ---> NHibernate.PropertyNotFoundException: Could not find field '_x' in class 'Model.Msp.Interfaces.ILittleXyz'

Which is completely correct since the interface doesn't have any private fields.
But the solutiion was simple as always it just took a little searching.
So i just changed the Littlexyz class to this.

<NHibernate.Mapping.Attributes.Component(classtype:=GetType(Model.Msp.Littlexyz))> _
    Public Class Littlexyz
        Implements ILittleXyz

#Region " Private members "
        ''' <summary>
        ''' A local variable called _x of type Decimal
        ''' </summary>
        ''' <remarks>Has Property X</remarks>
        Private _x As Decimal

Which does exactly what I want and what it should.