定义函数createFile创建一个文本文件person.txt，将n个Person对象写入文件，再定义函数readFile将文件中的信息读出显示在屏幕上c++

以下是示例代码，其中Person类需要根据具体需求自行定义：

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

using namespace std;

// Person类定义
class Person {
public:
    string name;
    int age;
    string gender;

    Person(string n, int a, string g) {
        name = n;
        age = a;
        gender = g;
    }
};

// 创建文件并写入n个Person对象
void createFile(string fileName, int n) {
    ofstream outFile(fileName);
    if (!outFile.is_open()) {
        cout << "Error: cannot create file " << fileName << endl;
        return;
    }

    for (int i = 0; i < n; i++) {
        string name;
        int age;
        string gender;

        cout << "Enter name for person " << i+1 << ": ";
        cin >> name;
        cout << "Enter age for person " << i+1 << ": ";
        cin >> age;
        cout << "Enter gender for person " << i+1 << ": ";
        cin >> gender;

        Person p(name, age, gender);
        outFile << p.name << " " << p.age << " " << p.gender << endl;
    }

    outFile.close();
}

// 读取文件并显示内容
void readFile(string fileName) {
    ifstream inFile(fileName);
    if (!inFile.is_open()) {
        cout << "Error: cannot open file " << fileName << endl;
        return;
    }

    vector<Person> persons;
    string line;
    while (getline(inFile, line)) {
        string name;
        int age;
        string gender;

        stringstream ss(line);
        ss >> name >> age >> gender;

        Person p(name, age, gender);
        persons.push_back(p);
    }

    inFile.close();

    for (int i = 0; i < persons.size(); i++) {
        cout << "Person " << i+1 << ": " << endl;
        cout << "Name: " << persons[i].name << endl;
        cout << "Age: " << persons[i].age << endl;
        cout << "Gender: " << persons[i].gender << endl;
    }
}

int main() {
    string fileName = "person.txt";
    int n;

    cout << "Enter the number of persons: ";
    cin >> n;

    createFile(fileName, n);
    cout << "File created successfully!" << endl;

    cout << "Press any key to read file..." << endl;
    getchar();
    readFile(fileName);

    return 0;
}

在运行程序时，会提示用户输入n个Person对象的信息，然后将这些信息写入文件中。再通过readFile函数读取文件内容并显示在屏幕上。