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Invalid handle error from ReadFileEx using valid handle from CreateFile

开发者 https://www.devze.com 2023-04-11 18:15 出处:网络
The problem I\'m having: CreateFile returns a handle of 0x194.ReadFileEx is saying that this handle is invalid.(Error 6.)Any ideas?The argument passed in is \"C:\\testfile.txt\", which is a valid text

The problem I'm having: CreateFile returns a handle of 0x194. ReadFileEx is saying that this handle is invalid. (Error 6.) Any ideas? The argument passed in is "C:\testfile.txt", which is a valid text file I made in Notepad. Despite being a C++ programmer for the last 12 years, this is my first time writing anything with "windows.h" or threads.

#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_SUCCE开发者_如何学JAVASS)
    {
        printf("A valid file is required., Error: %d", GetLastError());
        scanf("\n");
        return 0;
    }
    printf("%s", buffer);
    scanf("\n");
    delete buffer;
    return 0;
}


My guess is to change
ReadFileEx(&file, &buffer, 1024, &overlapped, NULL);
to
ReadFileEx(file, &buffer, 1024, &overlapped, NULL);

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