Csharp/C Sharp by API/System.Security.AccessControl/FileSecurity

FileSecurity.AddAccessRule

  
using System;
using System.IO;
using System.Security.AccessControl;
class MainClass {
    static void Main(string[] args) {
        FileStream stream;
        string fileName;
        fileName = Path.GetRandomFileName();
        using (stream = new FileStream(fileName, FileMode.Create)) {
            // Do something.
        }
        SetRule(fileName, "Everyone", FileSystemRights.Read, AccessControlType.Deny);
        try {
            stream = new FileStream(fileName, FileMode.Create);
        } catch (Exception ex) {
            Console.WriteLine(ex.ToString());
        } finally {
            stream.Close();
            stream.Dispose();
        }
    }
    static void AddRule(string filePath, string account, FileSystemRights rights, AccessControlType controlType) {
        FileSecurity fSecurity = File.GetAccessControl(filePath);
        fSecurity.AddAccessRule(new FileSystemAccessRule(account, rights, controlType));
        File.SetAccessControl(filePath, fSecurity);
    }
    static void SetRule(string filePath, string account, FileSystemRights rights, AccessControlType controlType) {
        FileSecurity fSecurity = File.GetAccessControl(filePath);
        fSecurity.ResetAccessRule(new FileSystemAccessRule(account, rights, controlType));
        File.SetAccessControl(filePath, fSecurity);
    }
}

FileSecurity.ResetAccessRule

  
using System;
using System.IO;
using System.Security.AccessControl;
static class MainClass
{
    static void Main(string[] args)
    {
        FileStream stream = null;
        string fileName = "c:\\test.txt";
        // Deny "Everyone" access to the file
        FileSecurity fSecurity = File.GetAccessControl(fileName);
        fSecurity.ResetAccessRule(new FileSystemAccessRule("Everyone",FileSystemRights.Read, AccessControlType.Deny));
        File.SetAccessControl(fileName, fSecurity);
        // Attempt to access file.
        try
        {
            stream = new FileStream(fileName, FileMode.Create);
        }
        catch (Exception ex)
        {
            Console.WriteLine("Exception thrown: ");
            Console.WriteLine(ex.ToString());
        }
        finally
        {
            stream.Close();
            stream.Dispose();
        }
    }
}