C++读取二进制文件方法详解

std::ifstream file("data.bin", std::ios::binary);
if (!file) {
    std::cerr << "无法打开文件！" << std::endl;
    return -1;
}

int value;
file.read(reinterpret_cast<char*>(&value), sizeof(value));
if (file.gcount() != sizeof(value)) {
    std::cerr << "读取数据不完整！" << std::endl;
}

char buffer[1024];
file.read(buffer, sizeof(buffer));
size_t bytesRead = file.gcount(); // 获取实际读取字节数

struct Person {
    char name[32];
    int age;
};

Person p;
file.read(reinterpret_cast<char*>(&p), sizeof(p));

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

std::ifstream file("example.bin", std::ios::binary);
if (!file) {
    std::cerr << "打开失败" << std::endl;
    return -1;
}

// 获取文件大小
file.seekg(0, std::ios::end);
std::streamsize size = file.tellg();
file.seekg(0, std::ios::beg);

std::vector<char> buffer(size);
file.read(buffer.data(), size);

if (file) {
    std::cout << "成功读取 " << size << " 字节" << std::endl;
} else {
    std::cerr << "读取不完整" << std::endl;
}