C++笔记6之IO操作

IO流

文本文件操作

void main(){
	char* fname = "c://dest.txt";
	//输出流
	ofstream fout(fname);
	//创建失败
	if (fout.bad()){ 
		return;
	}

	fout << "jack" << endl;
	fout << "rose" << endl;
	
	//关闭
	fout.close();

	//读取
	ifstream fin(fname);
	if (fin.bad()){
		return;
	}
	char ch;
	while (fin.get(ch)){
		//输出
		cout << ch;
	}
	fin.close();

	system("pause");
}

---

二进制文件

void main(){
	char* src = "c://src.jpg";
	char* dest = "c://dest.jpg";

	//输入流
	ifstream fin(src, ios::binary);
	//输出流
	ofstream fout(dest, ios::binary);

	if (fin.bad() || fout.bad()){
		return;
	}

	while (!fin.eof()){
		//读取
		char buff[1024] = {0};
		fin.read(buff,1024);

		//写入
		fout.write(buff,1024);
	}

	//关闭
	fin.close();
	fout.close();

	system("pause");
}

---

C++对象的持久化

class Person
{
public:
	Person()
	{

	}
	Person(char * name, int age)
	{
		this->name = name;
		this->age = age;
	}
	void print()
	{
		cout << name << "," << age << endl;
	}
private:
	char * name;
	int age;
};


void main()
{
	Person p1("柳岩", 22);
	Person p2("rose", 18);
	//输出流
	ofstream fout("c://c_obj.data", ios::binary);
	fout.write((char*)(&p1), sizeof(Person)); //指针能够读取到正确的数据，读取内存区的长度
	fout.write((char*)(&p2), sizeof(Person));
	fout.close();

	//输入流
	ifstream fin("c://c_obj.data", ios::binary);
	Person tmp;
	fin.read((char*)(&tmp), sizeof(Person));
	tmp.print();

	fin.read((char*)(&tmp), sizeof(Person));
	tmp.print();

	system("pause");

}