定义protobuf如下；
message Mypb
{
Exch exch = 1;
string id = 3;
double weight = 14;
uint32 index = 18;
}
enum Exch
{
BJ = 0;
TJ = 1;
NJ = 2;
}
代码为；

void Function((google::protobuf::Message&)msg)
{
const Descriptor* descriptor = msg.GetDescriptor();
const Reflection* reflection = msg.GetReflection();
const uint count = descriptor->field_count();
std::cout<<"count= "<<count<<std::endl;
for (int i = 1; i <= count; ++i)
{
const FieldDescriptor* goal_field = descriptor->FindFieldByNumber(i);
if(nullptr==goal_field)
{
continue;
}
std::cout<<"goal_field->name(): "<<goal_field->name();
}
}
int main()
{
Mypb tmp_comp;
tmp_comp.set_id("12345");
tmp_comp.set_weight(122.43);
tmp_comp.set_index(231321);
tmp_comp.set_exch(static_cast< Exch >(2));
Function((google::protobuf::Message&)tmp_comp);
}

此时count=4，那么for循环中调用FindFieldByNumber()时所能取到的字段号最大为4，那么就无法取到字段号为14的weight和18的high，这种不连续字段号的message该如何取值的？谢谢