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im trying to make an application that monitors the speed of the character in GTAV, iv found the address of the variable with cheat engine: http://i.stack.imgur.com/klyYV.png

and i made a function to open a handle to the game process:

/*returns INVALID_HANDLE_VALUE on failure*/ 
HANDLE openProcessByName(const char* name, DWORD access){
    PROCESSENTRY32 process;
    process.dwSize = sizeof(PROCESSENTRY32);

    HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);

    if(Process32First(snapshot, &process) == FALSE){//failure
        CloseHandle(snapshot);
        return INVALID_HANDLE_VALUE;
    }

    while(Process32Next(snapshot, &process) == TRUE){//skips first but thats system anyway
        if(_stricmp(process.szExeFile, name) == 0){//found it
            HANDLE processHandle = OpenProcess(access, FALSE, process.th32ProcessID);
            CloseHandle(snapshot);
            return processHandle;
        }
    }

    CloseHandle(snapshot);
    return INVALID_HANDLE_VALUE;//reached if the process is not found and its handle not returned above
}

in main i get the handle and try to read the memory location like so:

#include <tlhelp32.h>
#include <iostream>

HANDLE openProcessByName(const char* name, DWORD access);

int main(){
    HANDLE processHandle = openProcessByName("GTA5.exe", PROCESS_VM_READ);
    if (processHandle == INVALID_HANDLE_VALUE){
        std::cout << "invalid handle value" << std::endl;
        return 0;
    }

    float speed = 0.00;
    if (ReadProcessMemory(processHandle, (LPCVOID)0x7FF65EEA3940, &speed, (DWORD)sizeof(speed), NULL) == 0){
        std::cout << "failed to read value" << std::endl;
        std::cout << GetLastError() << std::endl;//return 299
    }else{
        std::cout << speed << std::endl;
    }

    CloseHandle(processHandle);
    return 0;
}

but it fails and prints "failed to read value". im assuming this has something to do with an address offset, iv been looking it up but i don't really get what people are talking about. btw the memory location is not static and changes when the game is restarted but i wanted to at least get it working with the actual memory address before i tried to find a way to get it dynamically.

so how do i find the actual memory address to use with the ReadProcessMemory function based on the address displayed in cheat engine.

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1 回答 1

1

这就是我最终这样做的方式（代码已被简化且未经测试）。该地址需要偏移游戏进程主模块的基地址。

void read() {
    MODULEENTRY32 mainModule = {0};
    HANDLE process = openProcessByName(PROCESS_NAME, PROCESS_VM_READ, &mainModule);

    float rawSpeed = 0.00f;
    ReadProcessMemory(process, (LPCVOID)(mainModule.modBaseAddr + MEMORY_ADDRESS), &rawSpeed, sizeof(rawSpeed), NULL);
}

//returns INVALID_HANDLE_VALUE on failure
HANDLE openProcessByName(const char* name, DWORD access, MODULEENTRY32* mainModule) {
    PROCESSENTRY32 process;
    process.dwSize = sizeof(PROCESSENTRY32);

    HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);

    if (Process32First(snapshot, &process) == FALSE) {//failure
        CloseHandle(snapshot);
        return INVALID_HANDLE_VALUE;
    }

    while (Process32Next(snapshot, &process) == TRUE) {//skips first but thats system anyway
        if (_stricmp(process.szExeFile, name) == 0) {//found it

            HANDLE modSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, process.th32ProcessID);
            mainModule->dwSize = sizeof(MODULEENTRY32);
            Module32First(modSnapshot, mainModule);

            HANDLE processHandle = OpenProcess(access, FALSE, process.th32ProcessID);

            CloseHandle(modSnapshot);
            CloseHandle(snapshot);
            return processHandle;
        }
    }

    CloseHandle(snapshot);
    return INVALID_HANDLE_VALUE;//reached if the process is not found and its handle not returned above
}
于 2016-04-29T18:47:36.963 回答