01.Imports System.Collections.Generic
02.Imports System.Linq
03.Imports System.Reflection
04.Imports System.Linq.Expressions
05.
06.Public Module IEnumerableHelper
07. Sub New()
08. End Sub
09.
10. Private orderBy_ As MethodInfo = GetType(Enumerable).GetMethods(BindingFlags.[Static] Or BindingFlags.[Public]) _
11. .Where(Function(x) x.Name = "OrderBy" AndAlso x.GetParameters().Length = 2).First()
12.
13. <System.Runtime.CompilerServices.Extension()> _
14. Public Function OrderBy(Of TSource)(source As IEnumerable(Of TSource), propertyName As String) As IEnumerable(Of TSource)
15. Dim pi = GetType(TSource).GetProperty(propertyName, BindingFlags.[Public] Or BindingFlags.FlattenHierarchy Or BindingFlags.Instance)
16. Dim selectorParam = Expression.Parameter(GetType(TSource), "keySelector")
17. Dim sourceParam = Expression.Parameter(GetType(IEnumerable(Of TSource)), "source")
18. Return Expression.Lambda(Of Func(Of IEnumerable(Of TSource),
19. IOrderedEnumerable(Of TSource)))(Expression.[Call](orderBy_.MakeGenericMethod(GetType(TSource), pi.PropertyType),
20. sourceParam, Expression.Lambda(GetType(Func(Of ,)).MakeGenericType(GetType(TSource), pi.PropertyType),
21. Expression.[Property](selectorParam, pi), selectorParam)), sourceParam).Compile()(source)
22. End Function
23.
24. <System.Runtime.CompilerServices.Extension()> _
25. Public Function OrderBy(Of TSource)(source As IEnumerable(Of TSource), propertyName As String, ascending As Boolean) As IEnumerable(Of TSource)
26. Return If(ascending, source.OrderBy(propertyName), source.OrderBy(propertyName).Reverse())
27. End Function
28.
29.End Module
