Nested Properties

[Doggo120]

Hey guys!

 

I'm using VB.net and I would want to have "property properties" of a class like this:

 

Thing.Property1 = "Yo!" (*1)

Thing.Property1.AnotherThing = 0

Thing.Property1.AnotherThing2 = True

 

I understand I can use 'property Property1 as class' but if I do that, Property1 must get or set a Class, not a variable (*1) which is what I want. The contextualized example would be something like this:

 

Music.Note = 32 (A number representing a musical note)

Music.Note.MIDINumber (Retrieve the MIDINumber of Note)

Music.Note.Name (Retrieve the name of Note)

 

You can see it in this case:

Textbox1.Text="Something"

Textbox1.Text.Length

 

...Well, thanks for your help! :D

Edited October 7, 2011 by Doggo120

[snarfblam]

In your example, Textbox1.Text.Length, the Textbox1.Text property returns string, which provides it's own properties, such as Length.

 

You would have to do the same thing. You would need a Note class (or struct) that the property returns.

Public Structure Note
   Dim _Value As Integer

   Public Sub Note(value As Integer)
       _Value = value
   End Sub

   Public Readonly Property Value() As Integer
       Get
           Return _Value
       End Get
   End Property

   Public ReadOnly Property Name() As String
       Get
           Throw New NotImplementedException("Put some code here")
       End Get
   End Property

   Public ReadOnly Property MidiNumber() As Integer
       Get
           Throw New NotImplementedException("Put some code here")
       End Get
   End Property
End Structure

Now you can create the Note property in your Music class.

   Dim _Note As Note
   Public Property Note() As Note
       Get
           Return _Note
       End Get
       Set(ByVal value As Note)
           _Note = value
       End Set
   End Property

Then, you could access it like so.

Music.Note = New Note(32)
MessageBox.Show(Music.Note.MidiNumber.ToString())
MessageBox.Show(Music.Note.Name)

Notice that all the properties are declared "Readonly." When working with structures, it's a good idea to make them immutable (meaning the Note objects can't be changed, but you can assign a new Note object to the Music.Note property.) If your curious, here is an explanation of why structures should be immutable. Or, just make Note a class instead of a structure.

[Doggo120]

Thank you so so so so (x1000) much! This is what I was looking for :)