typedef struct student_
{
 int sno;
 string sname;
}student;     //学生的结构


vector<student> data_vector
data_vector.push_back(student);
QByteArray binary_data;
binary_data.resize(sizeof(student)*data_vector.size());
memcpy(binary_data.data(),(char*)&data_vector[0],sizeof(student)*data_vector.size());


//类对象数据的还原
student* data = (student*)binary_data.data();