C++对象序列化

      C++语言对文件的处理有一些限制，对于后来出现的一些语言，如Pascal 和Java都提供了对对象进行序列化的支持，而C++只能通过C FILE s结构 或 C++自己的fstream 类来保存程序中变量的值。

 二进制序列化

     对象序列化包含保存对象中的某些值，这些值是来自类当中的成员变量。在目前的标准当中，C++不存在内在的对象序列化，为了达到对象序列化，可以用二进制序列化来实现。

   如果你想保存一个值到文件，fstream 类提供了以二进制形式保存该值的方法。当你想用二进制的形式保存一个变量，在定义ofstream变量的时候，要指定iso::binary.

例子如下：

将对象保存在stream

#include <fstream>#include <iostream>using namespace std;class Student{public:char   FullName[40];char   CompleteAddress[120];char   Gender;double Age;bool   LivesInASingleParentHome;};int main(){Student one;strcpy(one.FullName, "Ernestine Waller");strcpy(one.CompleteAddress, "824 Larson Drv, Silver Spring, MD 20910");one.Gender = 'F';one.Age = 16.50;one.LivesInASingleParentHome = true;ofstream ofs("fifthgrade.ros", ios::binary);ofs.write((char *)&one, sizeof(one));return 0;}

从stream流中读取对象

#include <fstream>#include <iostream>using namespace std;class Student{public:char   FullName[40];char   CompleteAddress[120];char   Gender;double Age;bool   LivesInASingleParentHome;};int main(){/*Student one;strcpy(one.FullName, "Ernestine Waller");strcpy(one.CompleteAddress, "824 Larson Drv, Silver Spring, MD 20910");one.Gender = 'F';one.Age = 16.50;one.LivesInASingleParentHome = true;ofstream ofs("fifthgrade.ros", ios::binary);ofs.write((char *)&one, sizeof(one));*/Student two;ifstream ifs("fifthgrade.ros", ios::binary);ifs.read((char *)&two, sizeof(two));cout << "Student Information\n";cout << "Student Name: " << two.FullName << endl;cout << "Address:      " << two.CompleteAddress << endl;if( two.Gender == 'f' || two.Gender == 'F' )cout << "Gender:       Female" << endl;else if( two.Gender == 'm' || two.Gender == 'M' )cout << "Gender:       Male" << endl;elsecout << "Gender:       Unknown" << endl;cout << "Age:          " << two.Age << endl;if( two.LivesInASingleParentHome == true )cout << "Lives in a single parent home" << endl;elsecout << "Doesn't live in a single parent home" << endl;cout << "\n";return 0;}

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