在C#中使用LockFileEX

using System;
using System.IO;
using System.Runtime.InteropServices;

class FileLockExample
{
    [DllImport("kernel32.dll", SetLastError = true)]
    static extern bool LockFileEx(IntPtr hFile, uint dwFlags, uint dwReserved, uint nNumberOfBytesToLockLow, uint nNumberOfBytesToLockHigh, ref System.Threading.NativeOverlapped lpOverlapped);

    [DllImport("kernel32.dll", SetLastError = true)]
    static extern bool UnlockFileEx(IntPtr hFile, uint dwReserved, uint nNumberOfBytesToUnlockLow, uint nNumberOfBytesToUnlockHigh, ref System.Threading.NativeOverlapped lpOverlapped);

    const uint LOCKFILE_EXCLUSIVE_LOCK = 2;
    const uint LOCKFILE_FAIL_IMMEDIATELY = 1;

    static void Main()
    {
        string fileName = "example.txt";
        FileStream fileStream = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);

        // Lock the first 10 bytes of the file
        uint numBytesToLock = 10;
        System.Threading.NativeOverlapped overlapped = new System.Threading.NativeOverlapped();
        overlapped.OffsetLow = 0;
        overlapped.OffsetHigh = 0;
        overlapped.EventHandle = IntPtr.Zero;

        bool result = LockFileEx(fileStream.SafeFileHandle.DangerousGetHandle(), LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY, 0, numBytesToLock, 0, ref overlapped);

        if (result)
        {
            Console.WriteLine("File locked successfully.");

            // Perform file operations here

            // Unlock the file
            result = UnlockFileEx(fileStream.SafeFileHandle.DangerousGetHandle(), 0, numBytesToLock, 0, ref overlapped);

            if (result)
            {
                Console.WriteLine("File unlocked successfully.");
            }
            else
            {
                Console.WriteLine("Error unlocking file: {0}", Marshal.GetLastWin32Error());
            }
        }
        else
        {
            Console.WriteLine("Error locking file: {0}", Marshal.GetLastWin32Error());
        }

        fileStream.Close();
    }
}