Use directcast to call a list

Question

I'm looking for a way to avoid using select case to access a specific list; I'll have about 90 lists on a module, and depending on a record selected on a listbox (manually populated with the name of most of the tables of my database, but not all of them) I need to read the items of the list. So I have something like this:

Public RelevantTables_Table001 As List(Of Table001) = New List(Of Table001)
Public RelevantTables_Table002 As List(Of Table002) = New List(Of Table002)
'...
Public RelevantTables_Table999 As List(Of Table999) = New List(Of Table999)

Class Table001
'code for populating RelevantTables_Table001
End Class

Class Table002
'code for populating RelevantTables_Table002
End Class

Class Table999
'code for populating RelevantTables_Table999
End Class

And now I need to read the relevant list, depending on an item picked on a listbox. For example if someone picks Table042 I need to read the items of the list RelevantTables_Table042.

I'm trying to use DirectCast for this, but I can't figure out how to do it.

Answer 1

Class:

Public Class Table
  Public Tablename As String
  Public Collection As New List(Of String)
  Public Overrides Function ToString() As String
    Return Me.TableName
  End Function
End Class

Create new List:

Private RelevantTable_Table001 As New Table
RelevantTable_Table001.Tablename = "Table001"
RelevantTable_Table001.Collection.Add("stuff")
...
'add the class and it will display the TableName since we 
'overrided the ToString function 
lsb.Items.Add(RelevantTable_Table001)
'class objects can be stored in the listbox as an object

Get the List object from the SelectedItem property.

Private Sub lsb_SelectedIndexChanged(sender As Object, e As EventArgs)
  Dim tableList = TryCast(DirectCast(sender, ListBox).SelectedItem, Table)
  If tableList IsNot Nothing Then
    'tableList is the reference to the table object you seek.
  End If
End Sub

To make a list of several objects(columns in a DGV) use a custom class:

Public Class MyCustomClass
  Public Property Prop1 As String
  Public Property Prop2 As String
  Public Property Prop3 As String
End Class

Then your Table.Collection would be a List(Of MyCustomClass) instead of a string, this will give you 3 items per collection items - which is a table. Does that fit your needs?

Answer 2

Make a list of lists, then use the subscript to access the correct list, such as

Public RelevantTables As List(Of List(Of table)) 

For Each item in RelevantTables(42)