Command to collapse all sections of code?

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.

CTRL + M + A will collapse all even in Html files.

These controls are also in the context menu under Outlining.

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

For outlining options: Go to Tools -> Options -> Text Editor -> C# -> Advanced -> Outlining for outlining options.