集合发生 meaning in English

set occurence

Called when the data - binding collection changes
在数据绑定集合发生更改时调用。
If it detects that the collection has been modified since iteration began
，它在探测到迭代开始之后集合发生修改时，会抛出
Occurs when the columns collection changes , either by adding or removing a column
在由于添加或删除列而使列集合发生变化时发生。
This is useful when a collection has changed in a significant way and change information is insufficient to recreate the object in memory from view state
方法仅保存更改信息）。当集合发生很大更改并且更改信息不足以在内存中从视图状态重新创建对象时，这十分有用。