MutexSecurity.RemoveAccessRuleSpecific(MutexAccessRule) Método

public:
 void RemoveAccessRuleSpecific(System::Security::AccessControl::MutexAccessRule ^ rule);

public void RemoveAccessRuleSpecific(System.Security.AccessControl.MutexAccessRule rule);

override this.RemoveAccessRuleSpecific : System.Security.AccessControl.MutexAccessRule -> unit

Public Sub RemoveAccessRuleSpecific (rule As MutexAccessRule)

Parâmetros

Exceções

Exemplos

O seguinte exemplo de código mostra que o RemoveAccessRuleSpecific método requer uma correspondência exata para remover uma regra, e que as regras para permitir e negar direitos são independentes uma da outra.

O exemplo cria um MutexSecurity objeto, adiciona regras que permitem e negam vários direitos ao utilizador atual, e depois funde direitos adicionais na Allow regra de acesso. O exemplo passa então a regra original Allow ao RemoveAccessRuleSpecific método e mostra os resultados, mostrando que nada é eliminado. O exemplo constrói então uma regra que corresponde à Allow regra no MutexSecurity objeto e utiliza com sucesso o RemoveAccessRuleSpecific método para remover a regra.

using System;
using System.Threading;
using System.Security.AccessControl;
using System.Security.Principal;

public class Example
{
    public static void Main()
    {
        // Create a string representing the current user.
        string user = Environment.UserDomainName + "\\" + 
            Environment.UserName;

        // Create a security object that grants no access.
        MutexSecurity mSec = new MutexSecurity();

        // Add a rule that grants the current user the 
        // right to enter or release the mutex.
        MutexAccessRule ruleA = new MutexAccessRule(user, 
            MutexRights.Synchronize | MutexRights.Modify, 
            AccessControlType.Allow);
        mSec.AddAccessRule(ruleA);

        // Add a rule that denies the current user the 
        // right to change permissions on the mutex.
        MutexAccessRule rule = new MutexAccessRule(user, 
            MutexRights.ChangePermissions, 
            AccessControlType.Deny);
        mSec.AddAccessRule(rule);

        // Display the rules in the security object.
        ShowSecurity(mSec);

        // Add a rule that allows the current user the 
        // right to read permissions on the mutex. This rule
        // is merged with the existing Allow rule.
        rule = new MutexAccessRule(user, 
            MutexRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.AddAccessRule(rule);

        ShowSecurity(mSec);

        // Attempt to remove the original rule (granting
        // the right to enter or release the mutex) with 
        // RemoveAccessRuleSpecific. The removal fails,
        // because the right to read the permissions on the 
        // mutex has been added to the rule, so that it no 
        // longer matches the original rule.
        Console.WriteLine("Attempt to use RemoveAccessRuleSpecific on the original rule.");
        mSec.RemoveAccessRuleSpecific(ruleA);

        ShowSecurity(mSec);

        // Create a rule that grants the current user 
        // the right to enter or release the mutex, and
        // to read permissions. Use this rule to remove
        // the Allow rule for the current user.
        Console.WriteLine("Use RemoveAccessRuleSpecific with the correct rights.");
        rule = new MutexAccessRule(user, 
            MutexRights.Synchronize | MutexRights.Modify | 
                MutexRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.RemoveAccessRuleSpecific(rule);

        ShowSecurity(mSec);
    }

    private static void ShowSecurity(MutexSecurity security)
    {
        Console.WriteLine("\r\nCurrent access rules:\r\n");

        foreach(MutexAccessRule ar in 
            security.GetAccessRules(true, true, typeof(NTAccount)))
        {
            Console.WriteLine("        User: {0}", ar.IdentityReference);
            Console.WriteLine("        Type: {0}", ar.AccessControlType);
            Console.WriteLine("      Rights: {0}", ar.MutexRights);
            Console.WriteLine();
        }
    }
}

/*This code example produces output similar to following:

Current access rules:

        User: TestDomain\TestUser
        Type: Deny
      Rights: ChangePermissions

        User: TestDomain\TestUser
        Type: Allow
      Rights: Modify, Synchronize


Current access rules:

        User: TestDomain\TestUser
        Type: Deny
      Rights: ChangePermissions

        User: TestDomain\TestUser
        Type: Allow
      Rights: Modify, ReadPermissions, Synchronize

Attempt to use RemoveAccessRuleSpecific on the original rule.

Current access rules:

        User: TestDomain\TestUser
        Type: Deny
      Rights: ChangePermissions

        User: TestDomain\TestUser
        Type: Allow
      Rights: Modify, ReadPermissions, Synchronize

Use RemoveAccessRuleSpecific with the correct rights.

Current access rules:

        User: TestDomain\TestUser
        Type: Deny
      Rights: ChangePermissions
 */

Imports System.Threading
Imports System.Security.AccessControl
Imports System.Security.Principal

Public Class Example

    Public Shared Sub Main()

        ' Create a string representing the current user.
        Dim user As String = Environment.UserDomainName _ 
            & "\" & Environment.UserName

        ' Create a security object that grants no access.
        Dim mSec As New MutexSecurity()

        ' Add a rule that grants the current user the 
        ' right to enter or release the mutex.
        Dim ruleA As New MutexAccessRule(user, _
            MutexRights.Synchronize _
            Or MutexRights.Modify, _
            AccessControlType.Allow)
        mSec.AddAccessRule(ruleA)

        ' Add a rule that denies the current user the 
        ' right to change permissions on the mutex.
        Dim rule As New MutexAccessRule(user, _
            MutexRights.ChangePermissions, _
            AccessControlType.Deny)
        mSec.AddAccessRule(rule)

        ' Display the rules in the security object.
        ShowSecurity(mSec)

        ' Add a rule that allows the current user the 
        ' right to read permissions on the mutex. This rule
        ' is merged with the existing Allow rule.
        rule = New MutexAccessRule(user, _
            MutexRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.AddAccessRule(rule)

        ShowSecurity(mSec)

        ' Attempt to remove the original rule (granting
        ' the right to enter or release the mutex) with 
        ' RemoveAccessRuleSpecific. The removal fails,
        ' because the right to read the permissions on the 
        ' mutex has been added to the rule, so that it no 
        ' longer matches the original rule.
        Console.WriteLine("Attempt to use RemoveAccessRuleSpecific on the original rule.")
        mSec.RemoveAccessRuleSpecific(ruleA)

        ShowSecurity(mSec)

        ' Create a rule that grants the current user 
        ' the right to enter or release the mutex, and
        ' to read permissions. Use this rule to remove
        ' the Allow rule for the current user.
        Console.WriteLine("Use RemoveAccessRuleSpecific with the correct rights.")
        rule = New MutexAccessRule(user, _
            MutexRights.Synchronize _
            Or MutexRights.Modify _
            Or MutexRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.RemoveAccessRuleSpecific(rule)

        ShowSecurity(mSec)
        
    End Sub 

    Private Shared Sub ShowSecurity(ByVal security As MutexSecurity)
        Console.WriteLine(vbCrLf & "Current access rules:" & vbCrLf)

        For Each ar As MutexAccessRule In _
            security.GetAccessRules(True, True, GetType(NTAccount))

            Console.WriteLine("        User: {0}", ar.IdentityReference)
            Console.WriteLine("        Type: {0}", ar.AccessControlType)
            Console.WriteLine("      Rights: {0}", ar.MutexRights)
            Console.WriteLine()
        Next

    End Sub
End Class 

'This code example produces output similar to following:
'
'Current access rules:
'
'        User: TestDomain\TestUser
'        Type: Deny
'      Rights: ChangePermissions
'
'        User: TestDomain\TestUser
'        Type: Allow
'      Rights: Modify, Synchronize
'
'
'Current access rules:
'
'        User: TestDomain\TestUser
'        Type: Deny
'      Rights: ChangePermissions
'
'        User: TestDomain\TestUser
'        Type: Allow
'      Rights: Modify, ReadPermissions, Synchronize
'
'Attempt to use RemoveAccessRuleSpecific on the original rule.
'
'Current access rules:
'
'        User: TestDomain\TestUser
'        Type: Deny
'      Rights: ChangePermissions
'
'        User: TestDomain\TestUser
'        Type: Allow
'      Rights: Modify, ReadPermissions, Synchronize
'
'Use RemoveAccessRuleSpecific with the correct rights.
'
'Current access rules:
'
'        User: TestDomain\TestUser
'        Type: Deny
'      Rights: ChangePermissions

Observações

A regra só é removida se corresponder rule exatamente a todos os detalhes, incluindo as bandeiras. Outras regras com o mesmo utilizador não AccessControlType são afetadas.