The C++ implementation of protocol buffers returns the byte and string types as std::string. This structure contains a length function telling you how long the corresponding data is (as well as the data itself.) Thus there is no special significance of embeded characters.
The setting functions accept a string too, or there are versions that accept a buffer and length. If you want to set a field you can just do this:
pb.set_foo( std::string( data, data_length ));or
pb.set_foo( data, data_length );
以上的方式在读取的时候,还是被转换为string（到第一个 )可以通过这样的方式解决：
pt.mutable_foo()，协议中再加上length即可