Report Length Of Tube Feature When Implemented with Visual Studio Issue

I ran the code for Report Length Of Tube Feature within the NX Developer Tab without problem. However, when I tried with Visual Studio (VB.NET), I get a few error messages

1. Declarations:

    Dim init_proc_ref As UF.UFUi.SelInitFnT = AddressOf init_proc_body
    Dim filter_proc_ref As UF.UFUi.SelFilterFnT = AddressOf tube_feature_filter

Errors:

Severity	Code	Description	Project	File	Line	Suppression State
Error	BC30002	Type 'UF.UFUi.SelInitFnT' is not defined.	

I tried some suggestions from Show Potential Fixes but none worked

2.  UF.UFConstants is not a member of UF

Could anyone help me?