为什么只有当可执行文件在 Visual Studio 下运行时 CreateFileA 才会失败？

我写了一个简单的check_file_ref函数使用 WinAPI 检查两个路径是否引用同一个文件。代码没问题。它是用 C 语言的 Visual Studio 2017 编译的（标志/TC).

奇怪的是CreateFileA当可执行文件在 Visual Studio 下运行（即执行而不调试）时，(winapi) 总是失败，返回无效的文件句柄。否则，当可执行文件在 Visual Studio 外部运行时，它会按预期工作。

任何情况下工作目录都是相同的。

main.c:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>

/**
 * Check whether two paths reference the same file.
 * @param p1 File path 1.
 * @param p2 File path 2.
 * @return 0 same file, 1 different files, < 0 on failure.
 */
int
check_file_ref(char const * p1, char const * p2)
{
    if ( !p1 || !p2 )
        return -1;
    if ( p1 == p2 )
        return 0;
    if ( strcmp(p1, p2) == 0 )
        return 0;

    int ret;
    DWORD share, flags;
    HANDLE f1, f2;
    BY_HANDLE_FILE_INFORMATION s1, s2;

    ret = -1;
    share = FILE_SHARE_READ | FILE_SHARE_WRITE;
    flags = FILE_ATTRIBUTE_NORMAL;

    f1 = CreateFileA(p1, GENERIC_READ, share, NULL, OPEN_EXISTING, flags, NULL);
    f2 = CreateFileA(p2, GENERIC_READ, share, NULL, OPEN_EXISTING, flags, NULL);

    if ( f1 == INVALID_HANDLE_VALUE ) {
        fprintf(stderr, "Could not open %s file, error %d\n", p1, GetLastError());
        goto cleanup;
    }
    if ( f2 == INVALID_HANDLE_VALUE ) {
        fprintf(stderr, "Could not open %s file, error %d\n", p2, GetLastError());
        goto cleanup;
    }
    if ( GetFileInformationByHandle(f1, &s1) == 0 ) {
        fprintf(stderr, "Could not get %s file information, error %d\n", p1, GetLastError());
        goto cleanup;
    }
    if ( GetFileInformationByHandle(f2, &s2) == 0 ) {
        fprintf(stderr, "Could not get %s file information, error %d\n", p2, GetLastError());
        goto cleanup;
    }

/*
    The identifier (low and high parts) and the volume serial number uniquely
    identify a file on a single computer. To determine whether two open handles
    represent the same file, combine the identifier and the volume serial number
    for each file and compare them.

    See
    https://learn.microsoft.com/fr-fr/windows/desktop/api/fileapi/nf-fileapi-getfileinformationbyhandle
    https://learn.microsoft.com/fr-fr/windows/desktop/api/fileapi/ns-fileapi-_by_handle_file_information
*/
    ret = !(s1.dwVolumeSerialNumber == s2.dwVolumeSerialNumber
        &&  s1.nFileIndexLow == s2.nFileIndexLow
        && s1.nFileIndexHigh == s2.nFileIndexHigh);

cleanup:
    CloseHandle(f2);
    CloseHandle(f1);
    return ret;
}


int main()
{
    int ret;
    char workingDir[256];

    /* Both paths reference the same file.
       One is relative, the other absolute. */
    char * p1 = "hello.txt";
    char * p2 = "C:/Users/bro/source/repos/tests/x64/Debug/hello.txt";

    ret = GetModuleFileNameA(NULL, workingDir, sizeof(workingDir));
    printf("working dir: %s\n", (ret == 0 ? "err" : workingDir));

    /* Should return 0. */
    ret = check_file_ref(p1, p2);
    printf("p1: %s\n", p1);
    printf("p2: %s\n", p2);
    printf("check_file_ret ret %d ", ret);

    if      ( ret == 0 ) printf("(same file)\n");
    else if ( ret == 1 ) printf("(different files)\n");
    else                 printf("(error)\n");

    return 0;
}

可视化下运行可执行文件：

创建文件A失败 https://i.stack.imgur.com/uCk1A.png

可执行文件直接从命令行运行：

CreateFileA 有效 https://i.stack.imgur.com/9q3cg.png

Why is CreateFileA仅当可执行文件在 Visual Studio 下运行时才失败？

当您从 VisualStudio 运行应用程序时，默认工作目录是项目位置，由 VS 宏定义$(ProjectDir)。您可以通过打开项目属性来更改它：右键单击中的项目解决方案浏览器并选择特性从上下文菜单中。那里选择调试并改变工作主任y 财产。例如，在您的情况下，解决方案可能是$(OutDir)或所需位置的绝对路径。