c++ - 使用来自 CreateFile 的有效句柄来自 ReadFileEx 的无效句柄错误

Question

我遇到的问题:CreateFile 返回 0x194 的句柄。 ReadFileEx 表示此句柄无效。 (错误 6。)有什么想法吗？传入的参数是“C:\testfile.txt”，这是我用记事本制作的有效文本文件。尽管在过去的 12 年里我一直是一名 C++ 程序员，但这是我第一次使用“windows.h”或线程编写任何东西。

#include "stdafx.h"
#include "stdio.h"
#include "windows.h"

using namespace System;

int main(int argc, char **argv)
{
    if (argc != 2)
    {
        printf("To display a file, you must enter the filename as the only command argument.");
        scanf("\n");
        return 0;
    }
    HANDLE file;
    int nameLen = (strlen(argv[1]) + 1);
    wchar_t *filename = new wchar_t[nameLen];
    if (filename == 0)
    {
        printf("To display a file, you must enter the filename as the only command argument.");
        scanf("\n");
        return 0;
    }
    memset(filename, 0, nameLen);
    ::MultiByteToWideChar(CP_ACP, NULL, argv[1], -1, filename, nameLen);
    file = CreateFile(filename, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (file == NULL)
    {
        printf("A valid filename is required.");
        scanf("\n");
        return 0;
    }
    char *buffer;
    buffer = new char[1024];
    OVERLAPPED overlapped;
    overlapped.Offset = overlapped.OffsetHigh = 0;
    ReadFileEx(file, &buffer, 1024, &overlapped, NULL);
    WaitForSingleObject(&file, 0);
    if (GetLastError() != ERROR_SUCCESS)
    {
        printf("A valid file is required., Error: %d", GetLastError());
        scanf("\n");
        return 0;
    }
    printf("%s", buffer);
    scanf("\n");
    delete buffer;
    return 0;
}

Answer 1

我的猜测是改变
ReadFileEx(&file, &buffer, 1024, &overlapped, NULL);
到
ReadFileEx(file, &buffer, 1024, &overlapped, NULL);