Imports System

Imports System.Collections.Generic

Imports System.Data

Imports System.Linq

Imports System.Reflection

Imports System.Runtime.CompilerServices

Imports DataTablePrettyPrinter

Public Module Module1

    Public Sub Main()

        Dim users = { New UserViewModel() With { .Username = "dday9" } }

        Dim auditLogs = { New AuditLogViewModel() With {.User = users.First(), .Description = "Foo"}, New AuditLogViewModel() With {.Description = "Bar"} }

        Dim dt = auditLogs.ToDataTable()

        Console.WriteLine(dt.ToPrettyPrintedString())

    End Sub

End Module

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Public Class UserViewModel

    Public Property Username As String

End Class

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Public Class AuditLogViewModel

    <DataTableIgnoreAttribute> Public Property User As UserViewModel

    Public ReadOnly Property Username As String

        Get

            If (User Is Nothing) Then

                Return String.Empty

            End If

            Return User.Username

        End Get

    End Property

    Public Property Description As String

End Class

​

Public Class DataTableIgnoreAttribute

    Inherits Attribute

​

    Public Property IgnoreColumn As Boolean

​

    Sub New()

        IgnoreColumn = True

    End Sub

​

End Class

​

Module DataTableExtensionModule

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    <Extension()>

    Public Function ToDataTable(Of T)(items As IEnumerable(Of T)) As DataTable

        Dim dataTableConverted = New DataTable(GetType(T).Name)

        Dim enumerableProperties = GetType(T). _

            GetProperties(BindingFlags.Public Or BindingFlags.Instance). _

            Where(Function(prop)

                      Dim dataTableIgnore = prop.GetCustomAttribute(Of DataTableIgnoreAttribute)

                      Return dataTableIgnore Is Nothing OrElse Not dataTableIgnore.IgnoreColumn

                  End Function). _

            ToArray()

​

        For Each prop In enumerableProperties

            dataTableConverted.Columns.Add(prop.Name, prop.PropertyType)

        Next

​

        For Each item In items

            Dim values = New Object(enumerableProperties.Length - 1) {}

​

            For i = 0 To enumerableProperties.Length - 1

                values(i) = enumerableProperties(i).GetValue(item, Nothing)

            Next

​

            dataTableConverted.Rows.Add(values)

        Next

​

        Return dataTableConverted

    End Function

​

End Module

​