Collapse all #regions only(!) in C# (Visual Studio)

in Visual Studio 2017 I have to activate 'Collapse #regions when collapsing to definitions' in

Tools -> Options -> Text Editor -> C# -> Advanced

explicitly to collapse all when pressing Ctrl+M+O

Ctrl+M+O will collapse all.

Ctrl+M+L will expand all. (in VS 2013 - Toggle All outlining)

Ctrl+M+P will expand all and disable outlining.

Ctrl+M+M will collapse/expand the current section.

These options are also in the context menu under Outlining.

Right click in editor -> Outlining to find all options. (After disabling outlining, use same steps to enable outlinging.)

The Visual Studio extension Productivity Power Tools 2015 from Microsoft has a feature called Quick Launch Tasks that adds new commands to the Quick Launch menu. One of them is CollapseRegions and it does exactly that.

The opposite command is ExpandRegions and it expands all regions for quick browsing of the entire file. These commands can be used pretty quickly by pressing the CtrlQ hotkey and typing Coll resp. Exp, then pressing Enter (supposed you don't have other commands with the same prefix).