关于MapViewOfFile函数的错误

Question

HANDLE hFile = CreateFile(filename,
GENERIC_READ,
FILE_SHARE_READ,
NULL,
OPEN_EXISTING,
FILE_FLAG_SEQUENTIAL_SCAN,
NULL);
HANDLE hFileMapping = CreateFileMapping(hFile,
NULL, 
PAGE_READONLY,
0,
0,
NULL);
__int64 qwFileOffset=0,qwNumOf0s=0,qwFileSize=m_FileSize,qwTempFileOffset=0;
__int64 sectionsize=0;
CloseHandle(hFile);
int count=m_ShowList1.GetItemCount();
for(int i=0;i<count;i++)
{
CString tempFile=m_ShowList1.GetItemText(i,0);//第一个文件名
CString tempBytestr=m_ShowList1.GetItemText(i,1);
int index=tempBytestr.Find('B');
if(index==-1)//错误处理
{
}
tempBytestr=tempBytestr.Left(index);
sectionsize=_atoi64(tempBytestr);
if(sectionsize<=0)//错误处理
{
}
     HANDLE TemphFile =CreateFile(tempFile, 
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_WRITE,
NULL,
            CREATE_NEW,
    FILE_ATTRIBUTE_NORMAL, 
NULL);
    HANDLE TemphFileMapping = CreateFileMapping(TemphFile, 
NULL, 
    PAGE_READWRITE,
(DWORD)(sectionsize>>32),
(DWORD)(sectionsize&0xFFFFFFFF),
NULL);
DWORD error=GetLastError();
CloseHandle(TemphFile);
__int64 Tempsectionsize=sectionsize;
while (Tempsectionsize > 0) 
{
DWORD dwBytesInBlock=m_sinfo.dwAllocationGranularity;

if(sectionsize<m_sinfo.dwAllocationGranularity)
dwBytesInBlock =(DWORD) sectionsize;

PBYTE pbFile=(PBYTE)MapViewOfFile(hFileMapping,
FILE_MAP_READ,
(DWORD)((qwFileOffset+qwTempFileOffset)>>32),          
(DWORD)((qwFileOffset+qwTempFileOffset)&0xFFFFFFFF), 
dwBytesInBlock);
PBYTE TemppbFile=(PBYTE)MapViewOfFile(TemphFileMapping,
FILE_MAP_WRITE,
     (DWORD)((qwTempFileOffset)>>32),
 (DWORD)((qwTempFileOffset)&0xFFFFFFFF),
 dwBytesInBlock);        
error=GetLastError();
//BYTE c,cc;
for(DWORD dwByte = 0; dwByte < dwBytesInBlock; dwByte++)
{
TemppbFile[dwByte] = pbFile[dwByte];
//qwNumOf0s++;
}

UnmapViewOfFile(TemppbFile);
UnmapViewOfFile(pbFile);

qwTempFileOffset += dwBytesInBlock;
Tempsectionsize -= dwBytesInBlock;
//TemppbFile++;
//pbFile++;
}
qwFileSize-=sectionsize;
qwFileOffset += sectionsize;
CloseHandle(TemphFileMapping);
}
CloseHandle(hFileMapping);上面标有红色的这句error=GetLastError();返回错误码为5，不知是哪里的错了

Answer 1

HANDLE hFile = CreateFile(filename,
        GENERIC_READ,
        FILE_SHARE_READ,
        NULL,
        OPEN_EXISTING,
        FILE_FLAG_SEQUENTIAL_SCAN,
        NULL);
    HANDLE hFileMapping = CreateFileMapping(hFile,
        NULL, 
        PAGE_READONLY,
        0,
        0,
        NULL);
    __int64 qwFileOffset=0,qwNumOf0s=0,qwFileSize=m_FileSize,qwTempFileOffset=0;
    __int64 sectionsize=0;
    CloseHandle(hFile);
    int count=m_ShowList1.GetItemCount();
    for(int i=0;i<count;i++)
    {
        CString tempFile=m_ShowList1.GetItemText(i,0);//第一个文件名
        CString tempBytestr=m_ShowList1.GetItemText(i,1);
        int index=tempBytestr.Find('B');
        if(index==-1)//错误处理
        {
        }
        tempBytestr=tempBytestr.Left(index);
        sectionsize=_atoi64(tempBytestr);
        if(sectionsize<=0)//错误处理
        {
        }
        HANDLE TemphFile =CreateFile(tempFile, 
            GENERIC_READ | GENERIC_WRITE,
            FILE_SHARE_WRITE,
            NULL,
            CREATE_NEW,
            FILE_ATTRIBUTE_NORMAL, 
            NULL);
        HANDLE TemphFileMapping = CreateFileMapping(TemphFile, 
            NULL, 
            PAGE_READWRITE,
            (DWORD)(sectionsize>>32),
            (DWORD)(sectionsize&0xFFFFFFFF),
            NULL);
        DWORD error=GetLastError();
        CloseHandle(TemphFile);
        __int64 Tempsectionsize=sectionsize;
        while (Tempsectionsize > 0) 
        {
            DWORD dwBytesInBlock=m_sinfo.dwAllocationGranularity;
            
            if(sectionsize<m_sinfo.dwAllocationGranularity)
                dwBytesInBlock =(DWORD) sectionsize;
            
            PBYTE pbFile=(PBYTE)MapViewOfFile(hFileMapping,
                FILE_MAP_READ,
                (DWORD)((qwFileOffset+qwTempFileOffset)>>32),          
                (DWORD)((qwFileOffset+qwTempFileOffset)&0xFFFFFFFF), 
                dwBytesInBlock);
            PBYTE TemppbFile=(PBYTE)MapViewOfFile(TemphFileMapping,
                FILE_MAP_WRITE,
                 (DWORD)((qwTempFileOffset)>>32),
                 (DWORD)((qwTempFileOffset)&0xFFFFFFFF),
                 dwBytesInBlock);        
               error=GetLastError();//就这句反回值为5，上面的MapViewOfFile函数反回NULL指针，不知是怎么错了？
                //BYTE c,cc;
                for(DWORD dwByte = 0; dwByte < dwBytesInBlock; dwByte++)
                {
                TemppbFile[dwByte] = pbFile[dwByte];
                //qwNumOf0s++;
                }
            
            UnmapViewOfFile(TemppbFile);
            UnmapViewOfFile(pbFile);
            
            qwTempFileOffset += dwBytesInBlock;
            Tempsectionsize -= dwBytesInBlock;
            //TemppbFile++;
            //pbFile++;
        }
        qwFileSize-=sectionsize;
        qwFileOffset += sectionsize;
        CloseHandle(TemphFileMapping);
    }
    CloseHandle(hFileMapping);

Answer 2

5 --- Access Deny,你的数据以及共享内存访问权限是否设置正确

Answer 3

可是for语句第一次循环时并没有错误的