For n As Integer = 1 To Sheet.Rows.Count -1

    Dim bh As String = sheet(n,0).Text

    If bh = "" Then

        Exit For

    End If

    Dim rr As DataRow = DataTables("rh_ytoex").SQLFind("运单号码 = \'" & bh & "\'")

    Dim dr As DataRow

    If rr Is Nothing Then

        dr =  tb.DataTable.AddNew()

    End If

    Dim m As Integer

        For m  = 0 To dh.Count - 1

            If Sheet(n,dh(m)).Value = "" Then

                Continue For

            Else

                dr(mc(m)) = Sheet(n,dh(m)).Value

            End If

        Next