主题：DateTimePicker的数据放进DataTable.LoadFilter 报错

Dim ddrq_s As WinForm.DateTimePicker = e.Form.Controls("ddrq_s")
Dim ordernodtp As WinForm.TextBox = e.Form.Controls("orderno")
If ordernodtp.Value <> "" Then
    sqlwhere += "[orderno] ='" & ordernodtp.Value & "' and "
End If
If ddrq_s.Value <> Nothing  Then
    sqlwhere += "[cdate] >='" & ddrq_s.Value & "' and "
End If
sqlwhere=sqlwhere.SubString(0,sqlwhere.LastIndexOf(" and "))
Tables("order").DataTable.LoadFilter = sqlwhere
Tables("order").DataTable.Load