在网上查了一下，虽然有很多文章介绍Protocol Buffer，但是实际使用起来，还是会遇到很多问题，所以我想应该有一个指南一样的东西，让新手很快就能使用它。
Protocol Buffer简写为Protobuf，是Google开发的一种储存数据的方式，功能与XML一样，但更方便，数据量更小，速度更快，在序列化和反序列化的时候使用，有很大的优势。比如，网络游戏的通讯协议编写。更重要的是，它是一个开源项目。
闲话不多说，下载地址：
http://code.google.com/p/protobuf/downloads/list
由于Protobuf不能生成C#代码，所以就要用到另外一个开源项目protobuf-net，下载地址：
http://code.google.com/p/protobuf-net/
@echo off
rem 查找文件
for /f "delims=" %%i in ('dir /b ".\*.proto"') do echo %%i
for /f "delims=" %%i in ('dir /b/a "*.proto"') do protoc -I=. --cpp_out=. %%i
for /f "delims=" %%i in ('dir /b/a "*.proto"') do protogen -i:%%i -o:%%~ni.cs
pause
用法是，在命令行用protoc.exe依据你自己定义的.proto文件，来生成.cpp文件
用protobuf-net的protogen.exe来生成.cs文件，可以写一个批处理，如下：
protoc -I=. --cpp_out=. Net.proto //在当前目录下，以cpp方式编译Net.proto
protogen -i:Net.proto -o:Net.cs //在当前目录下，用Net.proto生成Net.cs
其实两句功能是一样，只是分别生成了Net.proto的cpp文件和cs文件，这样就可以在两种语言编写的应用程序间通信了。
Net.proto文件内容如下：
- message SearchRequest {
- required string query = 1;
- optional int32 page_number = 2;
- optional int32 result_per_page = 3;
- }
数据类型如下：
| .proto Type | Notes | C++ Type | Java Type |
|---|---|---|---|
| double | double | double | |
| float | float | float | |
| int32 | Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint32 instead. | int32 | int |
| int64 | Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint64 instead. | int64 | long |
| uint32 | Uses variable-length encoding. | uint32 | int[1] |
| uint64 | Uses variable-length encoding. | uint64 | long[1] |
| sint32 | Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int32s. | int32 | int |
| sint64 | Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int64s. | int64 | long |
| fixed32 | Always four bytes. More efficient than uint32 if values are often greater than 228. | uint32 | int[1] |
| fixed64 | Always eight bytes. More efficient than uint64 if values are often greater than 256. | uint64 | long[1] |
| sfixed32 | Always four bytes. | int32 | int |
| sfixed64 | Always eight bytes. | int64 | long |
| bool | bool | boolean | |
| string | A string must always contain UTF-8 encoded or 7-bit ASCII text. | string | String |
| bytes | May contain any arbitrary sequence of bytes. | string | ByteString |