The example found on the csharp tutorial page doesn’t work. Instead do the following
- Open visual studio, open nuget command line, type :Install-Package Google.ProtocolBuffers , link : ProtocolBuffers 2.4.1.555
- Find Package/Google.ProtocolBuffers.2.4.1.555/tools/ProtoGen.exe
- Use command line, type : ProtoGen.exe addressbook.proto -output_directory=C:\trash
Source: Stackoverflow Post
Update 6/13/2017
Marc Gravell has an online tool for generating C# code from a .proto file.
http://protogen.marcgravell.com/