' 导入命名空间
Imports System.ComponentModel

Public Class Person
    Implements INotifyPropertyChanged

    ' Events
    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged

    ' Methods
    Public Sub New()
    End Sub

    Public Sub New(ByVal first As String, ByVal last As String, ByVal town As String)
        Me._firstname = first
        Me._lastname = last
        Me._hometown = town
    End Sub

    Private Sub OnPropertyChanged(ByVal info As String)
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(info))
    End Sub

    Public Overrides Function ToString() As String
        Return Me._firstname.ToString
    End Function


    ' Properties
    Public Property FirstName() As String
        Get
            Return Me._firstname
        End Get
        Set(ByVal value As String)
            Me._firstname = value
            Me.OnPropertyChanged("FirstName")
        End Set
    End Property

    Public Property HomeTown() As String
        Get
            Return Me._hometown
        End Get
        Set(ByVal value As String)
            Me._hometown = value
            Me.OnPropertyChanged("HomeTown")
        End Set
    End Property

    Public Property LastName() As String
        Get
            Return Me._lastname
        End Get
        Set(ByVal value As String)
            Me._lastname = value
            Me.OnPropertyChanged("LastName")
        End Set
    End Property


    ' Fields
    Private _firstname As String
    Private _hometown As String
    Private _lastname As String
End Class

Public Class PersonTemplateSelector
    Inherits DataTemplateSelector

    Public Overrides Function SelectTemplate(ByVal item As Object, _
                     ByVal container As DependencyObject) As DataTemplate

        ' The content of each TabItem is a Person object.
        If TypeOf item Is Person Then

            Dim person As Person = item

            Dim win As Window = Application.Current.MainWindow

            ' Select one of the DataTemplate objects, based on the 
            ' person's home town.
            If person.HomeTown = "Seattle" Then
                Return win.FindResource("SeattleTemplate")
            Else
                Return win.FindResource("DetailTemplate")

            End If
        End If

        Return Nothing
    End Function

End Class