virtual void LockRange( DWORD dwPos, DWORD dwCount );
throw( CFileException );
Parameters
dwPos
The byte offset of the start of the byte range to lock.
dwCount
The number of bytes in the range to lock.
Remarks
Locks a range of bytes in an open file, throwing an exception if the file is already locked. Locking bytes in a file prevents access to those bytes by other processes. You can lock more than one region of a file, but no overlapping regions are allowed.
When you unlock the region, using the UnlockRange member function, the byte range must correspond exactly to the region that was previously locked. The LockRange function does not merge adjacent regions; if two locked regions are adjacent, you must unlock each region separately.
Note This function is not available for the CMemFile-derived class.
Example
//example for CFile::LockRange
extern DWORD dwPos;
extern DWORD dwCount;
extern CFile cfile;
cfile.LockRange( dwPos, dwCount );
CFile Overview | Class Members | Hierarchy Chart
See Also CFile::UnlockRange