新手求助list(of)

//相关类型
            class City
            {
                public string Name{get;set;}
            }
            class Province
            {
                public string Name{get;set;}
                public List<City>CityList{get;set;}
            }
            class Country
            {
                public string Name{get;set;}
                public List<Province>Province{get;set;}
            }
            //Binding
            List <Country>CountryList=new List<Country>{/*初始化*/};
            this.TextBox6.SetBinding(TextBox.TextProperty,new Binding("/Name"),{Source = CountryList});
            this.TextBox7.SetBinding(TextBox.TextProperty,new Binding("/ProvinceList.Name"),{Source = CountryList});
            this.TextBox8.SetBinding(TextBox.TextProperty,new Binding("/Province/CityList.Name"),{Source = CountryList});

Sub aaa()
        Dim Co As New Country
        Dim CountryList As New List(Of Country)
        Dim arr1 As Array = {"云南", "四川"}
        Dim arr2 As Array = {"昆明", "曲靖", "宣威"}
        Dim arr3 As Array = {"重庆", "成都", "绵阳"}
        Co.Name = "中国"
        For j As Integer = 0 To 1
            Dim Pr As New Province
            If j = 0 Then
                Pr.Name = arr1(0)
                For i As Integer = 0 To 2
                    Dim Ci As New City
                    Ci.Name = arr2(i)
                    Pr.CityList.Add(Ci)
                Next
            Else
                Pr.Name = arr1(j)
                For i As Integer = 0 To 2
                    Dim Ci As New City
                    Ci.Name = arr3(i)
                    Pr.CityList.Add(Ci)
                Next
            End If
            Co.ProvinceList.Add(Pr)
        Next
        CountryList.Add(Co)
        Erase arr1, arr2, arr3
        Dim binding As New Binding
        binding.Source = CountryList
        binding.Path = New PropertyPath("/Name")
        BindingOperations.SetBinding(TextBox6, TextBox.TextProperty, binding)

        Dim binding1 As New Binding
        binding1.Source = CountryList
        binding1.Path = New PropertyPath("/ProvinceList/Name")
        BindingOperations.SetBinding(TextBox7, TextBox.TextProperty, binding1)

        Dim binding2 As New Binding
        binding2.Source = CountryList
        binding2.Path = New PropertyPath("/ProvinceList/CityList/Name")
        BindingOperations.SetBinding(TextBox8, TextBox.TextProperty, binding2)

    End Sub

Public Class Country
    Private _Name As String
    Private _ProvinceList As New List(Of Province)
    Public Property Name As String
        Get
            Return _Name
        End Get
        Set(ByVal value As String)
            _Name = value
        End Set
    End Property
    Public Property ProvinceList As List(Of Province)
        Get
            Return _ProvinceList
        End Get
        Set(ByVal value As List(Of Province))
            _ProvinceList = value
        End Set
    End Property
End Class

Public Class Province
    Private _Name As String
    Private _CityList As New List(Of City)
    Public Property Name As String
        Get
            Return _Name
        End Get
        Set(ByVal value As String)
            _Name = value
        End Set
    End Property
    Public Property CityList As List(Of City)
        Get
            Return _CityList
        End Get
        Set(ByVal value As List(Of City))
            _CityList = value
        End Set
    End Property
End Class

Public Class City
    Private _Name As String
    Public Property Name As String
        Get
            Return _Name
        End Get
        Set(ByVal value As String)
            _Name = value
        End Set
    End Property
End Class