How to reformat all C# files in a solution, in Visual Studio 2012. Also on Stack Overflow: http://stackoverflow.com/q/15458332/5314

gistfile1.ps1

# How to reformat all C# files in a solution, in Visual Studio 2012. 
#
# Open Tools->Library Package Manager->Package Manager Console, and run the 
# command below. At the end, all documents will be open in the IDE. (Low-RAM 
# machines will have problems with large solutions.) Changed files will be 
# modified in the IDE, and not saved to disk. You can SaveAll, then Close All 
# if you're ready.
#
# VS2012 removed the VB-like macro language that existed in previous version of 
# Visual Studio. However, the underlying DTE interface is still there, and you 
# can reach it via PowerShell, in the Package Manager Console
#
# The weird GUID passed to [ProjectItem.Open](http://msdn.microsoft.com/en-us/library/envdte.projectitem.open.aspx) 
# is [Constants.vsViewKindCode](http://msdn.microsoft.com/en-us/library/envdte.constants.vsviewkindcode.aspx).
#
# Normally I'd split this in to multiple lines, but the Package Manager Console 
# doesn't support line continuation.

function f($projectItems) { $projectItems | ? { $_.Name -ne $null -and $_.Name.EndsWith( ".cs" ) -and -not $_.Name.EndsWith( ".Designer.cs" ) } | % { $win = $_.Open('{7651A701-06E5-11D1-8EBD-00A0C90F26EA}') ; $win.Activate() ; $DTE.ExecuteCommand('Edit.FormatDocument') } ; if ($projectItems) { $projectItems | % { f($_.projectItems) } } }

$dte.Solution.Projects | % { f($_.ProjectItems) }

Thanks for this script.
Here is a small merge request to Exclude auto-generated files when formatting code ("*.Designer.cs"):
https://gist.github.com/ubikuity/62335a46d4439b94a034