主题：在窗口中多选时，如何能目录树分级显示？

下拉框选值，反映到目录树：

Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
For Each nd As WinForm.TreeNode In trv.AllNodes
    If e.Sender.Text.Contains(nd.Name) Then
        nd.Checked = True
    End If
Next
trv.ExpandAll()

目录树选值，反映到下拉框： 

Dim trv As WinForm.TreeView = e.Sender
Dim txt As String
For Each nd As WinForm.TreeNode In trv.AllNodes
    If nd.Level = 1 Then
        If nd.Checked = True Then
            txt = txt & "," & nd.Name       
        End If
    Else
        nd.Checked = False
    End If
Next
If txt > "" Then
    txt = txt.Trim(",")
End If
e.Form.Controls("CheckedComboBox1").Text = txt