我无法获得以编程方式添加到TreeView中的节点的名称

Question

每当我在现有的TreeView中添加一个新节点时，我的代码似乎就无法检测到它的名称。请有人解释。

所有其他数据在加载表单之前都是通过TreeView设计进行编码的。

请参阅屏幕截图以供参考。

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    Dim newNode As TreeNode = New TreeNode(TextBox1.Text)
    TreeView1.SelectedNode.Nodes.Add(newNode)
    transfer_dgv1()
End Sub

Private Sub transfer_dgv1()
    Dim TreeViewRW As New TreeViewrw
    TreeView1.Refresh()
    Me.DataGridView1.DataSource = TreeViewRW.ToTable(Me.TreeView1)
End Sub

这是我使用的功能：

Public Class TreeViewrw

    Public Function ToTable(ByVal tv As TreeView) As DataTable
        Dim dt As New DataTable("TreeNodes")
        Dim id As Integer = 1

        dt.Columns.Add("ParentID", GetType(Integer))
        dt.Columns.Add("NodeID", GetType(Integer))
        dt.Columns.Add("Name", GetType(String))

        For Each pn As TreeNode In tv.Nodes
            dt.Rows.Add(0, id, pn.Name)
            Me.GetAllNodes(dt, pn, id, id)
            id += 1
        Next
        Return dt
    End Function

    Public Function FromTable(ByVal dt As DataTable, ByVal parent As String, ByVal node As String, ByVal name As String) As TreeNode()
        Dim tnodes As New List(Of TreeNode)()
        Dim columns As String() = New String(2) {parent, node, name}

        If dt.Columns.Contains(parent) AndAlso dt.Columns.Contains(node) AndAlso dt.Columns.Contains(name) Then
            dt.DefaultView.RowFilter = "[" & parent & "] = 0"
            For Each r As DataRowView In dt.DefaultView
                tnodes.Add(Me.ReadNodes(columns, r, dt))
            Next
            Return tnodes.ToArray()
        Else
            Return tnodes.ToArray()
        End If
    End Function

    Private Function ReadNodes(ByVal columns As String(), ByVal r As DataRowView, ByVal dt As DataTable) As TreeNode
        Dim cn As New TreeNode()

        cn.Name = r(columns(2)).ToString()
        cn.Text = cn.Name

        Me.GetAllNodes(columns, cn, dt, CInt(r(columns(1))))
        Return cn
    End Function

    Private Sub GetAllNodes(ByRef dt As DataTable, ByVal pn As TreeNode, ByVal parentid As Integer, ByRef id As Integer)
        For Each cn As TreeNode In pn.Nodes
            id += 1
            dt.Rows.Add(parentid, id, cn.Name)
            Me.GetAllNodes(dt, cn, id, id)
        Next
    End Sub

    Private Sub GetAllNodes(ByVal columns As String(), ByRef pn As TreeNode, ByVal dt As DataTable, ByVal nodeid As Integer)
        dt.DefaultView.RowFilter = ("[" & columns(0).ToString() & "] = ") + nodeid.ToString()

        For Each r As DataRowView In dt.DefaultView
            Dim cn As New TreeNode()

            cn.Name = r(columns(2)).ToString()
            cn.Text = cn.Name
            pn.Nodes.Add(cn)
            Me.GetAllNodes(columns, cn, dt, CInt(r(columns(1))))
        Next
    End Sub
End Class

Answer 1

我似乎您没有设置Name属性。

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    Dim newNode As TreeNode = New TreeNode(TextBox1.Text)
    newNode.Name = TextBox1.Text
    TreeView1.SelectedNode.Nodes.Add(newNode)
    transfer_dgv1()
End Sub