For i As Integer = DataTables("表A").datarows.Count - 1 To 0 Step -1 Dim dr As DataRow = DataTables("表A").datarows(i) Dim count As Integer = 0 For Each dc As DataCol In DataTables("表A").DataCols If dr.IsNull(dc.Name) Then count += 1 Next If count >= 4 Then dr.delete End If Next