How can I sort an array of a structure? - arrays

Question

I have an array of a structure.
It's declared like this
Public SongsList as New List(Of Song)
"Song" it's structure's name.
It has 2 variables : path and name;
I'm wondering how I can sort this array by the name.
Public Structure Song
Public Path as String
Public Name as String
End Structure
I tried this
ListBox1.Items.Clear()
Dim sorted = SongsList.OrderBy(Function(s) s.Name).ToList
Dim i As Integer
For i = 0 To sorted.Count - 1
ListBox1.Items.Add(sorted(i).Name.ToString)
Next
But it throws a NullReferenceException.
This is how I'm adding items to SongsList
Dim open As New OpenFileDialog
open.Title = "Add songs"
open.Filter = "MP3 Files(*.mp3)|*.mp3"
open.Multiselect = True
ListBox1.Items.Clear()
If open.ShowDialog = DialogResult.OK Then
For Each SelectedSong As String In open.FileNames
i += 1
Dim songToAdd As New Song
songToAdd.Path = SelectedSong.ToString
songToAdd.Name = GetSafeFileName(SelectedSong.ToString)
SongsList.Add(songToAdd)
ListBox1.Items.Add(SongsList(i).Path)
Next
End If

Answer 1

You can use a Lambda expression. It uses the field you select in the OrderBy function. Lets Override the ToString method to tell the Listbox what to display, then you can just set the list as the datasource.
The class:
Public Class Song
Public Property Path as String
Public Property Name as String
Public Overrides Function ToString() As String
Return Me.Path
End If
End Class
Usage:
Dim open As New OpenFileDialog
open.Title = "Add songs"
open.Filter = "MP3 Files(*.mp3)|*.mp3"
open.Multiselect = True
If open.ShowDialog = DialogResult.OK Then
For Each SelectedSong As String In open.FileNames
Dim songToAdd As New Song
songToAdd.Path = SelectedSong
songToAdd.Name = GetSafeFileName(SelectedSong.ToString)
SongsList.Add(songToAdd)
Next
End If
Listbox1.DataSource = SongsList.OrderBy(Function(s) s.Name).ToList

Answer 2

*Very similar to OneFineDay's answer...
You don't need a custom class, just use a List(Of FileInfo):
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim open As New OpenFileDialog
open.Title = "Add songs"
open.Filter = "MP3 Files(*.mp3)|*.mp3"
open.Multiselect = True
If open.ShowDialog = DialogResult.OK Then
ListBox1.DataSource = Nothing
Dim songs As New List(Of FileInfo)
For Each SelectedSong As String In open.FileNames
songs.Add(New FileInfo(SelectedSong))
Next
songs = songs.OrderBy(Function(fi) fi.Name).ToList
ListBox1.DataSource = songs
ListBox1.DisplayMember = "Name"
ListBox1.ValueMember = "FullName"
End If
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
If ListBox1.SelectedIndex <> -1 Then
Dim fi As FileInfo = DirectCast(ListBox1.SelectedItem, FileInfo)
Dim name As String = fi.Name
Dim fullPath As String = fi.FullName
Debug.Print("name = " & name)
Debug.Print("fullPath = " & fullPath)
End If
End Sub