主题：[求助]为什么不能正常返回字符列的最大字符长度？

Dim lst2 As WinForm.ListBox = e.Form.Controls("ListBox2")

lst2.items.Clear

Dim biaoname As String = lst.SelectedItem

'MessageBox.Show(biaoname)

Dim cmd As new SQLCommand

cmd.C

cmd.CommandText = "select * From {" & biaoname & "} Where [_Identify] Is Null"

Dim dt As DataTable = cmd.ExecuteReader

Dim Value As String

For Each dc As DataCol In dt.DataCols

    'output.show(dc.name & ":" & dc.datatype.name)

    Value = dc.datatype.name

    Select Case Value

        Case = "String"

            lst2.Items.Add(dc.name & "(" & dc.datatype.name & "," & dc.MaxLength & ")")

        Case Else

            lst2.Items.Add(dc.name & "(" & dc.datatype.name & ")")

    End Select

Next