This directory contains the C# Protocol Buffers runtime library.
The easiest way how to use C# protobufs is via the
NuGet package. Just add the NuGet package to your VS project.
You will also want to install the
Google.Protobuf.Tools NuGet package, which
contains precompiled version of
protoc.exe and a copy of well known
files under the package's
To generate C# files from your
.proto files, invoke
protoc with the
The runtime library is built as a portable class library, supporting:
- .NET 4.5
- Windows 8
- Windows Phone Silverlight 8
- Windows Phone 8.1
- .NET Core
You should be able to use Protocol Buffers in Visual Studio 2012 and
all later versions. This includes all code generated by
which only uses features from C# 3 and earlier.
src/Google.Protobuf.sln solution in Visual Studio 2017 or
Although users of this project are only expected to have Visual
Studio 2012 or later, developers of the library are required to
have Visual Studio 2017 or later, as the library uses C# 6 features
in its implementation, as well as the new Visual Studio 2017 csproj
format. These features have no impact when using the compiled code -
they're only relevant when building the
In order to run and debug the AddressBook example in the IDE, you must install the optional component, ".Net Core 1.0 - 1.1 development tools for Web" (as it's labelled in current versions of the VS2017 installer), above and beyond the main .NET Core cross-platform development feature.
The unit tests use NUnit 3. Tests can be
run using the Visual Studio Test Explorer or
We don't officially support .NET 3.5. However, there has been some effort to make enabling .NET 3.5 support relatively painless in case you require it. There's no guarantee that this will continue in the future, so rely on .NET 3.5 support at your peril.
To enable .NET 3.5 support, you must edit the
TargetFrameworks elements of
if you want to run the unit tests):
Open the .csproj file in a text editor and simply add
net35 to the list of
target frameworks, noting that the
TargetFrameworks element appears twice in
the file (once in the first
PropertyGroup element, and again in the second
PropertyGroup element, i.e., the one with the conditional).
History of C# protobufs
This subtree was originally imported from https://github.com/jskeet/protobuf-csharp-port and represents the latest development version of C# protobufs, that will now be developed and maintained by Google. All the development will be done in open, under this repository (https://github.com/google/protobuf).
The previous project differs from this project in a number of ways:
- The old code only supported proto2; the new code only supports proto3 (so no unknown fields, no required/optional distinction, no extensions)
- The old code was based on immutable message types and builders for them
- The old code did not support maps or
- The old code had its own JSON representation, whereas the new code uses the standard protobuf JSON representation
- The old code had no notion of the "well-known types" which have special support in the new code
- The old project supported some older platforms (such as older versions of Silverlight) which are not currently supported in the new project