一个例子：客户在销售订单行项目上创建了一个扩展字段A，这个字段的值是最终用户手动输入的：
An example: Suppose customer has already created one extension field named “Special Net Price” on Sales Order item level.
然后客户又创建了另一个扩展字段B：
Now customer would like to see one more extension field “Special Total Value” whose content is calculated as :
Special Total Value = Quantity * Special Net Price, in the example above = 45 * 100 = 4500 USD.
这个扩展字段B的值是计算而来的，公式是标准字段quantity乘以扩展字段A。
如何实现？
Just create a new Calculated Field in key user tool:
Output:
要获取更多Jerry的原创文章，请关注公众号"汪子熙":