windows内核驱动读写文件

VOID FileOption()
{
    HANDLE SourceFileHandle = NULL;      //源文件句柄
    HANDLE TargetFileHandle = NULL;      //目标文件句柄
    NTSTATUS Status = STATUS_SUCCESS;    //返回状态
    OBJECT_ATTRIBUTES ObjectAttributes;  //OBJECT_ATTRIBUTES结构
    UNICODE_STRING SourceFilePath = RTL_CONSTANT_STRING(L"\\??\\c:\\source.txt"); //源文件
    UNICODE_STRING TargetFilePath = RTL_CONSTANT_STRING(L"\\??\\c:\\target.txt"); //目标文件
    UNICODE_STRING String = {0};           //指向Buffer
    IO_STATUS_BLOCK IoStatusBlock;         //返回结果状态结构体
    PVOID Buffer = NULL;                   //buffer指针
    USHORT Length = 0;                     //要读写的长度
    LARGE_INTEGER Offset = {0};            //要读写的偏移

    //初始化OBJECT_ATTRIBUTES结构体
    InitializeObjectAttributes(
        &ObjectAttributes,
        &SourceFilePath,
        OBJ_CASE_INSENSITIVE|OBJ_KERNEL_HANDLE,
        NULL,
        NULL);

    //以FILE_OVERWRITE_IF方式打开
    Status = ZwCreateFile(
        &SourceFileHandle,
        GENERIC_READ|GENERIC_WRITE|SYNCHRONIZE,
        &ObjectAttributes,
        &IoStatusBlock,
        NULL,
        FILE_ATTRIBUTE_NORMAL,

        FILE_SHARE_READ,
        FILE_OVERWRITE_IF,
        FILE_NON_DIRECTORY_FILE|
        FILE_RANDOM_ACCESS|
        FILE_SYNCHRONOUS_IO_NONALERT,
        NULL,
        0);
    if (!NT_SUCCESS(Status))
    {
        DbgPrint("Open source file fault !! - %#x\n", Status);
        return Status;
    }

    //字符串操作
    //动态申请内存
    Buffer = (PWCHAR)ExAllocatePoolWithTag(NonPagedPool, 1024, 'Tag1');
    if (NULL == Buffer)
    {
        DbgPrint("申请Buffer失败!!\n");
        ZwClose(SourceFileHandle);
        Status = STATUS_INSUFFICIENT_RESOURCES;
        return Status;
    }
    //初始化字符串指针
    RtlInitEmptyUnicodeString(&String, Buffer, 512*sizeof(WCHAR));
    //拷贝字符串
    RtlCopyUnicodeString(&String, &SourceFilePath);
    //追加Unicode变量
    RtlAppendUnicodeStringToString(&String, &TargetFilePath);
    //追加字符串