This:

New FieldPropertyDescriptor() { }

Tells it to create a new array of type FieldPropertyDescriptor.  Whatever you put in the curly braces are items in the newly created array (ReflectionPropertyDescriptor is a subclass of FieldPropertyDescriptor).  So, it needs to look like this:

Return New FieldPropertyDescriptor() { New ReflectionPropertyDescriptor("Ctr", GetType(boCalc)), _
    New ReflectionPropertyDescriptor("Ftr", GetType(boCalc)) }

Any others that you add just need to be separated by commas.

I tried somthing like this but doesnt work

Protected Overrides Function GetCustomBindablePropertyDescriptors() As FieldPropertyDescriptor()

Return New FieldPropertyDescriptor() {New ReflectionPropertyDescriptor("Ctr", GetType(boCalc))}

Return New FieldPropertyDescriptor() {New ReflectionPropertyDescriptor("Ftr", GetType(boCalc))}

End Function

As for the Type.GetType(boCalc), it's a shared (static) method on the System.Type class, and it only accepts strings, but the GetType(boCalc) is a language keyword, so it accepts the type and knows how to compile it.

And you figured out the creating a new array rather than returinging only a single instance.

Okay I figured it out.

Protected Overrides Function GetCustomBindablePropertyDescriptors() As FieldPropertyDescriptor()

Return New FieldPropertyDescriptor() {New ReflectionPropertyDescriptor("Ctr", GetType(boCalc))}

End Function

This is what I have so far but it doesnt like boCalc.

Protected Overrides Function GetCustomBindablePropertyDescriptors() As FieldPropertyDescriptor()

Return New ReflectionPropertyDescriptor("Ctr", Type.GetType(boCalc))

End Function

http://forum.strataframe.net/FindPost3479.aspx