主题：如何直接统计每个字段为空的个数？

参考代码

Dim dt As DataTable = DataTables("员工资料")
Dim ndr As DataRow = DataTables("校验").AddNew
For Each dc As DataCol In dt.DataCols
    ndr(dc.name) = dt.Compute("count(_Identify)", dc.name & " is null")
Next