主题：“编辑目录树之一”能运用在网络系统中吗？

版主是正确的。但在增加节点，并保存时有出错提示，如下图：

 

此主题相关图片如下：qq图片20160111160358.png

Dim dt As DataTable = DataTables("表A")
Dim dic As New Dictionary(of Integer, Integer)
Dim ids As String = ""
Dim prevLevel As Integer = 0
For Each nd As WinForm.TreeNode In e.Form.Controls("TreeView1").AllNodes
    If nd.Level = 0 AndAlso dic.count > 0 Then
        Dim temp = dic(0)
        dic.Clear
        dic.Add(0, temp)
    End If
   
    If dic.ContainsKey(nd.Level) = False Then
        dic.Add(nd.Level, 1)
    Else
        dic(nd.Level) = dic(nd.Level) + 1
    End If
    For i As Integer = nd.level + 1 To prevLevel
        dic(i) = 0
    Next
   
    prevLevel = nd.Level
   
    Dim ndr As DataRow = Nothing
    If nd.tag > "" Then
        ndr = dt.find("_Identify = " & nd.tag)
    End If
    If ndr Is Nothing Then
        ndr= dt.AddNew
        nd.tag = ndr("_Identify")
    End If
    Dim str As String = ""
    For i As Integer = 0 To nd.Level
        str &= dic(i) & "."
    Next
    ndr("第一列") = str.TrimEnd(".")
    ndr("第二列") = nd.Text
    ids &= nd.tag & ","
Next
dt.deletefor("_Identify not in (" & ids.trim(",") & ")")

谢谢！