Spread for WinForms 11 no longer returns PartCollapsed state of group model. Instead, it collapses the complete group when collapsing a few rows of the group.

Spread for WinForms 10 did not support expanding or collapsing of a group at it’s summary cell index. Now, this behavior is supported and hence the compatibility with Excel is sustained.

In Spread for WinForms 10, the first level group was expanded when 0 was passed as the parameter value. In Spread for WinForms 11, this is handled by throwing an exception with message: the input group does not exist.