Answers for "how to collapse all in visual studio"

visual studio 2019 collapse all

Ctrl + M + O will collapse all. Ctrl + M + P will expand all

visual studio code collapse all

// Fold
Ctrl + K + 0 // fold everything that could be folded
Ctrl + K + 1 // fold just the main branches

// Unfold
Ctrl + K + J // unfold everything

collapse all code visual studio

Visual studio 
fold all: Ctrl + M + O
unfold all: Ctrl + M + P