qt文件操作读写自定义类型

#include <QtCore/QCoreApplication> #include <QFile> #include <QDataStream> #include <QString> #include <iostream> using namespace std; class Dog { public: Dog() { _number = 0; } Dog(int number, const QString &name) { _number = number; _name = name; } void setNumber(int number) { _number = number; } int number() const { return _number; } void setName(const QString &name) { _name = name; } QString name() const { return _name; } private: int _number; QString _name; }; QDataStream &operator<<(QDataStream &out, const Dog &dog) { out << dog.number() << dog.name(); return out; } QDataStream &operator>>(QDataStream &in, Dog &dog) { int number = 0; QString name; in >> number >> name; dog.setNumber(number); dog.setName(name); return in; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); QFile file("data.dat"); Dog dog1(1, "caterpillar"); Dog dog2(2, "momor"); if(!file.open(QIODevice::WriteOnly)) { cerr << "Cannot open file for writing: " << qPrintable(file.errorString()) << endl; return false; } QDataStream out(&file); out.setVersion(QDataStream::Qt_4_3); out << dog1 << dog2; file.close(); if(!file.open(QIODevice::ReadOnly)) { cerr << "Cannot open file for reading: " << qPrintable(file.errorString()) << endl; return false; } QDataStream in(&file); in.setVersion(QDataStream::Qt_4_3); in >> dog1 >> dog2; cout << dog1.number() << ", " << qPrintable(dog1.name()) << endl << dog2.number() << ", " << qPrintable(dog2.name()) << endl; return a.exec(); }