It is simplest to help you get all function with one key operation without any PC software.

这是最简单的一个按键操作没有任何PC软件，以帮助您的所有功能。

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If more than one column is aggregated using the same grouping key or without a grouping key, then all the aggregations are computed within the same operation with a single pass over the data.

如果利用相同的分组关键字或者没有分组关键字，来聚合多个列，那么，所有的聚合都在单个数据传递中的相同操作中进行。

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Key operations in the control lifecycle are wrapped by a pair of events, one firing before the operation takes place and one firing immediately after the operation has completed.

控件生命周期中的关键操作被包装在一对事件中，一个在操作发生前触发，另一个在操作完成后立即触发。

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