如何在VB.NET中使用Dictionary类

Question

I am trying to create a Dictionary collection of keys, where each key would have a corresponding value of class "look". The following example does not work. It gives me:
first - circle, blue
second - circle, blue
While I need:
first - square, red
second - circle, blue
Why does it not work and how can I make it work?
Thank you.

Public Class Form1

Public Class look
    Public shape As String
    Public color As String
End Class

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim myDict As New Dictionary(Of String, look)
    Dim oLook As New look
    oLook.shape = "square"
    oLook.color = "red"
    myDict.Add("first", oLook)
    oLook.shape = "circle"
    oLook.color = "blue"
    myDict.Add("second", oLook)
    For Each key In myDict.Keys
        MsgBox(key & " - " & myDict(key).shape & ", " & myDict(key).color)
    Next
End Sub
End Class

Answer 1

You need a new instance of the class:

    Dim myDict As New Dictionary(Of String, look)
    Dim oLook As New look
    oLook.shape = "square"
    oLook.color = "red"
    myDict.Add("first", oLook)
    oLook = New look '<<<<<<<<<<<<
    oLook.shape = "circle"
    oLook.color = "blue"
    myDict.Add("second", oLook)
    For Each key In myDict.Keys
        MsgBox(key & " - " & myDict(key).shape & ", " & myDict(key).color)
    Next

Answer 2

Try this:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim myDict As New Dictionary(Of String, look)
    Dim oLook As New look
    oLook.shape = "square"
    oLook.color = "red"
    myDict.Add("first", oLook)
    oLook = new look ' This will create another oLook object and point olook at it.
    oLook.shape = "circle"
    oLook.color = "blue"
    myDict.Add("second", oLook)
    For Each key In myDict.Keys
        MsgBox(key & " - " & myDict(key).shape & ", " & myDict(key).color)
    Next
End Sub