新增节点后马上修改节点名称报错，如果是修改以前的节点就没问题。

 
此主题相关图片如下：qq截图20191105154957.png

此主题相关图片如下：qq截图20191105154818.png

导航表的 DataColChanged 事件代码如下：红色代码没执行

请老师看看，还是不对

If e.DataCol.Name="分类" OrElse e.DataCol.Name="分组" OrElse  e.DataCol.Name="名称"  Then
    Dim fn As winform.form=vars("editForm")
    If fn.Opened Then
        Dim tr As WinForm.TreeView = fn.Controls("TreeView1")
        For Each sd As  WinForm.TreeNode In tr.AllNodes
            Select Case sd.Level
                Case 0
                    Dim dr As DataRow = DataTables(vars("editTable")).Find("[分类] Like \'%" & sd.Text & "\' and 分组 is null")
                    If dr IsNot Nothing Then
                        If sd.Text = e.OldValue AndAlso dr("父键")=e.DataRow("父键")  Then
                        sd.Text= e.NewValue
                        End If
                    End If
                    Dim drs As List(Of  DataRow)
                    drs = DataTables(vars("editTable")).Select("[分类] = \'" & e.OldValue & "\' and [父键] = \'" & e.DataRow("父键") &  "\'")
                    For Each dr1 As DataRow In drs
                        dr1("分类") = e.NewValue
                    Next
                Case 1
                    Dim dr As DataRow = DataTables(vars("editTable")).Find("[分类] Like \'%" & sd.parentnode.Text & "\' and 分组 = \'" & sd.Text & "\' and 名称 is null")
                    If dr IsNot Nothing Then
                        If sd.Text = e.OldValue  AndAlso dr("子键")=e.DataRow("子键")  Then
                        sd.Text= e.NewValue
                        End If
                    End If
                    Dim drs As List(Of  DataRow)
                    drs = DataTables(vars("editTable")).Select("[分组] = \'" & e.OldValue & "\' and [子键] = \'" & e.DataRow("子键") &  "\'")
                    For Each dr2 As DataRow In drs
                        dr2("分组") = e.NewValue
                    Next
                Case 2
                    Dim dr As DataRow = DataTables(vars("editTable")).Find("[分类] Like \'%" & sd.parentnode.parentnode.Text & "\' and 分组 = \'" & sd.parentnode.Text & "\' and 名称 = \'" & sd.Text & "\'")
                    If dr IsNot Nothing Then
                        If sd.Text = e.OldValue AndAlso dr("序号")=e.DataRow("序号")  Then
                            sd.Text=e.NewValue
                        End If
                    End If
                    Dim drs As List(Of  DataRow)
                    drs = DataTables(vars("editTable")).Select("[名称] = \'" & e.OldValue & "\' and [序号] = \'" & e.DataRow("序号") &  "\'")
                    For Each dr3 As DataRow In drs
                        dr3("名称") = e.NewValue
                    Next
            End Select
        Next
    End If
End If

.NET Framework 版本：4.0.30319.42000
Foxtable 版本：2019.10.26.1
错误所在事件：表，导航，DataColChanged
详细错误信息：
调用的目标发生了异常。
未将对象引用设置到对象的实例。

老师，报错，4就没出来！

If e.DataCol.Name="名称" Then
    Dim fn As winform.form=vars("editForm")
msgbox(1)
    If fn.Opened Then
        Dim tr As WinForm.TreeView = fn.Controls("TreeView1")
msgbox(2)
        Dim node As WinForm.TreeNode = tr.Nodes(e.DataRow("分类"))
msgbox(3)
        If node IsNot Nothing AndAlso node.Nodes.count > 0 Then
            node = node.Nodes(e.DataRow("分组"))
msgbox(4)
            If node IsNot Nothing AndAlso node.Nodes.count > 0  Then
                node = node.Nodes(e.OldValue)
msgbox(5)
                If node IsNot Nothing Then
                    node .Text=e.NewValue
msgbox(6)
                End If
            End If
        End If
    End If
msgbox(7)

老师，3后面的代码没执行，直接就报错，报错的原因好像是这样的：

 
此主题相关图片如下：qq截图20191106095744.png

老师，数据正常了，在新增节点时，OldValue为空，还没有（node = node.Nodes(e.OldValue)）这个节点，执行到6报这个错是什么原因？

此主题相关图片如下：qq截图20191106102711.png

msgbox(1)
        Dim s As String = e.DataRow("分类")
msgbox(2)
        Dim node As WinForm.TreeNode = tr.Nodes(s.trim())
msgbox(3)
        If node IsNot Nothing AndAlso node.Nodes.count > 0 Then
msgbox(4)
            node = node.Nodes(e.DataRow("分组"))
msgbox(5)
            If node IsNot Nothing AndAlso node.Nodes.count > 0  Then
msgbox(6)
                node = node.Nodes(e.OldValue)
msgbox(7)
                If node IsNot Nothing Then
msgbox(8)
                    node .Text=e.NewValue
msgbox(9)
                End If