Visual Studio Minimize regions shortcut?

C-m, C-o // collapse all
C-m, C-l // expand all
C-m, C-m // collapse, expand one

Where C is short for Ctrl. You can find more shortcuts at the msdn site

You can find the commands by going to Keyboard Options under the Tools menu, they are mapped to these commands

• Edit.CollapseToDefinitions (C-m, C-o),
• Edit.ToggleOutliningExpansion (C-m, C-m) and
• Edit.ToggleAllOutlining (C-m, C-l)

If you are using Visual Studio Code the commands are similar but work differently. The commands are roughly these

• C-k 2 - Fold Level 2
• C-k C-j - Unfold all
• C-k [ - Unfold recursively (unfold where the caret is)

You can search for Fold or Unfold commands (using C-S-p) to find all of them.

Ctrl + M, Ctrl + M

You can perform this on a selection too.