You can use the sort method found in the Array class. You can implement IComparable in your structure. Basically this allows objects of type MyStructure to be compared. Here is a simple example.
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim people As Person() = {New Person("Bob", "Smith"), New Person("Chris", "Adams")}
Array.Sort(people)
For Each p As Person In people
Console.WriteLine(p.FirstName & ":" & p.LastName)
Next
End Sub
End Class
Public Structure Person
Implements IComparable(Of Person)
Public FirstName As String
Public LastName As String
Public Sub New(ByVal first As String, ByVal last As String)
FirstName = first
LastName = last
End Sub
Public Function CompareTo(ByVal other As Person) As Integer Implements System.IComparable(Of Person).CompareTo
Return String.Compare(Me.LastName, other.LastName)
End Function
End Structure
This will sort alphabetically by the LastName field. If you want to sort in descending order you could first call sort to put them in ascending order and then call array.reverse(YourArray) to put them in descedning order. There are other ways to allow for multiple different sorts. If you want to learn more about it try looking up the interfaces Icomparer, and Icomparable.