重载QDataStream<<和>>运算符序列化和反序列化

qdatastream_overload.cpp

#include <QDataStream>
#include <QString>
#include <QDebug>

struct Data1
{
	bool    isOk;
	int     value;
	QString str;
};

struct Data2
{
	bool    isOk;
	int     value;
	QString str;

	// member funtion to serialize
	Data2& operator>>(QDataStream& out)
	{
		out << isOk; // output to QDataStream
		out << value;
		out << str;
		return *this;
	}

	// member funtion to deserialize
	Data2& operator<<(QDataStream& in)
	{
		in >> isOk; // input from QDataStream
		in >> value;
		in >> str;
		return *this;
	}
};

// use non-member funtion to serialize
QDataStream& operator<<(QDataStream& out, const Data1& d)
{
	out << d.isOk; // output to QDataStream
	out << d.value;
	out << d.str;
	return out;
}

// use non-member funtion to deserialize
QDataStream& operator>>(QDataStream& in, Data1& d)
{
	in >> d.isOk; // input from QDataStream
	in >> d.value;
	in >> d.str;
	return in;
}

int main()
{
	{
		Data1 d;
		d.isOk  = true;
		d.value = 123;
		d.str   = "456";

		QByteArray ba;

		{
			QDataStream ds(&ba, QIODevice::WriteOnly);
			ds << d;
			qDebug() << "serialize" << d.isOk << d.value << d.str;
		}

		{
			QDataStream ds(&ba, QIODevice::ReadOnly);
			Data1       newD;
			ds >> newD;
			qDebug() << "deserialize" << newD.isOk << newD.value << newD.str;
		}
	}

	{
		Data2 d;
		d.isOk  = true;
		d.value = 432;
		d.str   = "111";

		QByteArray ba;

		{
			QDataStream ds(&ba, QIODevice::WriteOnly);
			d >> ds;
			qDebug() << "serialize" << d.isOk << d.value << d.str;
		}

		{
			QDataStream ds(&ba, QIODevice::ReadOnly);
			Data2       newD;
			newD << ds;
			qDebug() << "deserialize" << newD.isOk << newD.value << newD.str;
		}
	}

	return 0;
}