7.03-一个类写入文件.cpp

Visual C++的课件

#include <fstream.h>

class Animal
{
public:
	Animal(int weight, long days):itsWeight(weight),itsNumberDaysAlive(days){}
	~Animal(){}

	int GetWeight()const { return itsWeight; }
	void SetWeight(int weight) { itsWeight = weight; }

	long GetDaysAlive()const { return  itsNumberDaysAlive; }
	void SetDaysAlive(long days) { itsNumberDaysAlive = days; }

private:
	int itsWeight;
	long itsNumberDaysAlive;
};

int main()   // returns 1 on error
{
	char fileName[80];


	cout << "Please enter the file name: ";
	cin >> fileName;
	ofstream fout(fileName); //,ios::binary);
	if (!fout)
	{
		cout << "Unable to open " << fileName << " for writing.\n";
		return(1);
	}

	Animal Bear(50,100);
	fout.write((char*) &Bear,sizeof Bear);

	fout.close();

	ifstream fin(fileName,ios::binary);
	if (!fin)
	{
		cout << "Unable to open " << fileName << " for reading.\n";
		return(1);
	}

	Animal BearTwo(1,1);

	cout << "BearTwo weight: " << BearTwo.GetWeight() << endl;
	cout << "BearTwo days: " << BearTwo.GetDaysAlive() << endl;

	fin.read((char*) &BearTwo, sizeof BearTwo);

	cout << "BearTwo weight: " << BearTwo.GetWeight() << endl;
	cout << "BearTwo days: " << BearTwo.GetDaysAlive() << endl;
	fin.close();
	return 0;
}