锁定文件块

Question

I have a file that is 192k in size, I want to lock the middle of the file.

Ex) I would like to lock 64k-128k of the file with c#. Any idea how I would lock that part of the file?

Answer 1

You'll need to use LockFileEx

Locks the specified file for exclusive access by the calling process. This function can operate either synchronously or asynchronously and can request either an exclusive or a shared lock.

You're looking for a shared lock.

[DllImport("kernel32.dll")]
static extern bool LockFileEx(IntPtr hFile, uint dwFlags, uint dwReserved,
   uint nNumberOfBytesToLockLow, uint nNumberOfBytesToLockHigh,
   [In] ref System.Threading.NativeOverlapped lpOverlapped);

Answer 2

You might want to look into the LockFile function in the Windows API. The same page also mentions a LockFileEx function. Yay! Have tons of fun mucking around ;)

The pinvoke site has a page on it: http://www.pinvoke.net/default.aspx/kernel32.lockfile

Answer 3

You cant lock parts of a file using System.IO . If you have a open handle on the file, the complete file is locked.

You can do this using WinAPI.

Check out Using LockFileEX in C#