a.exe通过preocess调用b.exe , b.exe运行结束如何返回一个string类型的结果

在b.exe运行结束时，可以通过将结果写入共享内存或文件的方式来实现返回string类型的结果。具体步骤如下：

1. 在a.exe中创建一个共享内存或文件，用于存储b.exe返回的结果。

2. 在a.exe中启动b.exe进程，并将共享内存地址或文件路径作为参数传递给b.exe。

3. 在b.exe中将结果写入共享内存或文件中。

4. 在a.exe中读取共享内存中的结果或读取文件中的结果，并将其转换为string类型。

下面是一个示例代码：

在a.exe中：

#include <windows.h>
#include <iostream>

int main()
{
    HANDLE hMapFile = CreateFileMapping(
        INVALID_HANDLE_VALUE,    // use paging file
        NULL,                    // default security
        PAGE_READWRITE,          // read/write access
        0,                       // maximum object size (high-order DWORD)
        sizeof(char[256]),       // maximum object size (low-order DWORD)
        "Local\\MyFileMappingObject"); // name of the mapping object

    if (hMapFile == NULL)
    {
        std::cout << "Could not create file mapping object: " << GetLastError() << std::endl;
        return 1;
    }

    char* pBuffer = (char*)MapViewOfFile(
        hMapFile,          // handle to mapping object
        FILE_MAP_ALL_ACCESS, // read/write permission
        0,  // high-order DWORD of offset
        0,  // low-order DWORD of offset
        256); // number of bytes to map

    if (pBuffer == NULL)
    {
        std::cout << "Could not map view of file: " << GetLastError() << std::endl;
        CloseHandle(hMapFile);
        return 1;
    }

    STARTUPINFO si = { 0 };
    si.cb = sizeof(si);
    PROCESS_INFORMATION pi = { 0 };

    TCHAR szPath[MAX_PATH];
    GetModuleFileName(NULL, szPath, MAX_PATH);

    if (!CreateProcess(szPath, (LPSTR)"b.exe Local\\MyFileMappingObject", NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi))
    {
        std::cout << "CreateProcess failed: " << GetLastError() << std::endl;
        UnmapViewOfFile(pBuffer);
        CloseHandle(hMapFile);
        return 1;
    }

    WaitForSingleObject(pi.hProcess, INFINITE);

    std::cout << "Result from b.exe: " << pBuffer << std::endl;

    UnmapViewOfFile(pBuffer);
    CloseHandle(hMapFile);

    return 0;
}

在b.exe中：

#include <windows.h>
#include <iostream>

int main(int argc, char* argv[])
{
    HANDLE hMapFile = OpenFileMapping(
        FILE_MAP_ALL_ACCESS,   // read/write access
        FALSE,                 // do not inherit the name
        argv[1]);              // name of the mapping object

    if (hMapFile == NULL)
    {
        std::cout << "Could not open file mapping object: " << GetLastError() << std::endl;
        return 1;
    }

    char* pBuffer = (char*)MapViewOfFile(
        hMapFile,           // handle to mapping object
        FILE_MAP_WRITE,     // write permission
        0,                  // high-order DWORD of offset
        0,                  // low-order DWORD of offset
        256);               // number of bytes to map

    if (pBuffer == NULL)
    {
        std::cout << "Could not map view of file: " << GetLastError() << std::endl;
        CloseHandle(hMapFile);
        return 1;
    }

    strcpy_s(pBuffer, 256, "Hello, World!");

    UnmapViewOfFile(pBuffer);
    CloseHandle(hMapFile);

    return 0;
}