VS2019下C++代码的pch.h错误及三类警告修复求助

一、#include "pch.h" 错误修复 #

针对这个错误，按以下两种场景处理：

• 若项目不需要预编译头：右键项目→属性→配置属性→C/C++→预编译头，将“预编译头”选项改为“不使用预编译头”，然后删除代码中的#include "pch.h"。
• 若项目需要预编译头：确保项目根目录存在pch.h和pch.cpp文件，且#include "pch.h"是代码中第一个被包含的头文件。

二、三个警告的修复 #

1. 使用未初始化内存警告（涉及processesSnapshot） #

问题核心：原GetPID函数中，找到目标进程后提前关闭了句柄，但后续while(Process32Next(...))仍在使用已失效的句柄；同时逻辑错误，找到匹配进程后未立即返回，导致最终返回的PID可能不是目标进程的ID。

修复后的GetPID函数：

DWORD GetPID(const char* ProcessName) {
    PROCESSENTRY32 processInfo;
    processInfo.dwSize = sizeof(processInfo);

    HANDLE processesSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
    if (processesSnapshot == INVALID_HANDLE_VALUE)
        return 0;

    DWORD targetPID = 0;
    // 先检查第一个进程
    if (Process32First(processesSnapshot, &processInfo)) {
        if (!strcmp(processInfo.szExeFile, ProcessName)) {
            targetPID = processInfo.th32ProcessID;
        } else {
            // 遍历剩余进程，找到后立即退出循环
            while (Process32Next(processesSnapshot, &processInfo)) {
                if (!strcmp(processInfo.szExeFile, ProcessName)) {
                    targetPID = processInfo.th32ProcessID;
                    break;
                }
            }
        }
    }
    CloseHandle(processesSnapshot); // 统一在最后关闭句柄，避免无效句柄被复用
    return targetPID;
}

2. unsigned __int64转unsigned long/DWORD的参数转换警告 #

问题核心：main函数中pid被定义为unsigned long long，但GetModule的第二个参数是unsigned long，OpenProcess的第三个参数是DWORD（等价于unsigned long），64位类型转32位类型会触发数据丢失警告。

修复方式：将pid的类型改为Windows API标准的进程ID类型DWORD，同时同步修改GetModule的参数类型：

// 修改GetModule的参数类型为DWORD
MODULEENTRY32 GetModule(const char* moduleName, DWORD ProcessID)
{
    MODULEENTRY32 modEntry = { 0 };

    HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE | TH32CS_SNAPMODULE32, ProcessID);

    if (hSnapshot != INVALID_HANDLE_VALUE) {
        MODULEENTRY32 curr = { 0 };
        curr.dwSize = sizeof(MODULEENTRY32);
        if (Module32First(hSnapshot, &curr)) {
            do {
                if (!strcmp(curr.szModule, moduleName)) {
                    modEntry = curr;
                    break;
                }
            } while (Module32Next(hSnapshot, &curr));
        }
        CloseHandle(hSnapshot);
    }
    return modEntry;
}

// main函数中pid改为DWORD类型
int main()
{
    std::cout << "Hello World!\n";
    DWORD pid = GetPID("ac_client.exe");
    MODULEENTRY32 module = GetModule("ac_client.exe", pid);
    HANDLE phandle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid);

    // 内存地址相关的unsigned long long保留以适配64位进程
    unsigned long long result;
    int ammodesiredvalue = 999999;
    ReadProcessMemory(phandle, (void*)((unsigned long long)module.modBaseAddr + 0x0010B1E0), &result, sizeof(result), 0);
    ReadProcessMemory(phandle, (void*)((unsigned long long)result + 0x54), &result, sizeof(result), 0);
    ReadProcessMemory(phandle, (void*)((unsigned long long)result + 0x14), &result, sizeof(result), 0);
    WriteProcessMemory(phandle, (void*)((unsigned long long)result + 0x14), &ammodesiredvalue, sizeof(ammodesiredvalue), 0);
    std::cout << "Your ammo value is " << result << std::endl;

    system("pause");
}

修复后的完整代码 #

#include "pch.h" // 不需要预编译头可删除
#include <iostream>
#include <Windows.h>
#include <TlHelp32.h>
#include <cstring>

DWORD GetPID(const char* ProcessName) {
    PROCESSENTRY32 processInfo;
    processInfo.dwSize = sizeof(processInfo);

    HANDLE processesSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
    if (processesSnapshot == INVALID_HANDLE_VALUE)
        return 0;

    DWORD targetPID = 0;
    if (Process32First(processesSnapshot, &processInfo)) {
        if (!strcmp(processInfo.szExeFile, ProcessName)) {
            targetPID = processInfo.th32ProcessID;
        } else {
            while (Process32Next(processesSnapshot, &processInfo)) {
                if (!strcmp(processInfo.szExeFile, ProcessName)) {
                    targetPID = processInfo.th32ProcessID;
                    break;
                }
            }
        }
    }
    CloseHandle(processesSnapshot);
    return targetPID;
}

MODULEENTRY32 GetModule(const char* moduleName, DWORD ProcessID)
{
    MODULEENTRY32 modEntry = { 0 };

    HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE | TH32CS_SNAPMODULE32, ProcessID);

    if (hSnapshot != INVALID_HANDLE_VALUE) {
        MODULEENTRY32 curr = { 0 };
        curr.dwSize = sizeof(MODULEENTRY32);
        if (Module32First(hSnapshot, &curr)) {
            do {
                if (!strcmp(curr.szModule, moduleName)) {
                    modEntry = curr;
                    break;
                }
            } while (Module32Next(hSnapshot, &curr));
        }
        CloseHandle(hSnapshot);
    }
    return modEntry;
}

int main()
{
    std::cout << "Hello World!\n";
    DWORD pid = GetPID("ac_client.exe");
    if (pid == 0) {
        std::cout << "未找到ac_client.exe进程\n";
        system("pause");
        return 1;
    }
    MODULEENTRY32 module = GetModule("ac_client.exe", pid);
    if (module.modBaseAddr == 0) {
        std::cout << "未找到ac_client.exe模块\n";
        system("pause");
        return 1;
    }
    HANDLE phandle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid);
    if (phandle == NULL) {
        std::cout << "打开进程失败，错误码：" << GetLastError() << "\n";
        system("pause");
        return 1;
    }

    unsigned long long result;
    int ammodesiredvalue = 999999;
    if (!ReadProcessMemory(phandle, (void*)((unsigned long long)module.modBaseAddr + 0x0010B1E0), &result, sizeof(result), nullptr)) {
        std::cout << "读取内存失败，错误码：" << GetLastError() << "\n";
        CloseHandle(phandle);
        system("pause");
        return 1;
    }
    if (!ReadProcessMemory(phandle, (void*)((unsigned long long)result + 0x54), &result, sizeof(result), nullptr)) {
        std::cout << "读取内存失败，错误码：" << GetLastError() << "\n";
        CloseHandle(phandle);
        system("pause");
        return 1;
    }
    if (!ReadProcessMemory(phandle, (void*)((unsigned long long)result + 0x14), &result, sizeof(result), nullptr)) {
        std::cout << "读取内存失败，错误码：" << GetLastError() << "\n";
        CloseHandle(phandle);
        system("pause");
        return 1;
    }
    if (!WriteProcessMemory(phandle, (void*)((unsigned long long)result + 0x14), &ammodesiredvalue, sizeof(ammodesiredvalue), nullptr)) {
        std::cout << "写入内存失败，错误码：" << GetLastError() << "\n";
        CloseHandle(phandle);
        system("pause");
        return 1;
    }
    std::cout << "当前弹药值为：" << result << std::endl;

    CloseHandle(phandle);
    system("pause");
    return 0;
}

内容的提问来源于stack exchange，提问作者Muhammed Mostaafa