MutexSecurity.RemoveAccessRule(MutexAccessRule) Método

public:
 bool RemoveAccessRule(System::Security::AccessControl::MutexAccessRule ^ rule);

public bool RemoveAccessRule(System.Security.AccessControl.MutexAccessRule rule);

override this.RemoveAccessRule : System.Security.AccessControl.MutexAccessRule -> bool

Public Function RemoveAccessRule (rule As MutexAccessRule) As Boolean

Parâmetros

Devoluções

true se for encontrada uma regra compatível; caso contrário false.

Exceções

Exemplos

O exemplo de código seguinte demonstra a utilização do RemoveAccessRule método para remover direitos de uma Allow regra num MutexSecurity objeto. Também mostra que outros direitos rule são ignorados.

O exemplo cria um MutexSecurity objeto e adiciona regras que permitem e negam vários direitos ao utilizador atual. Os direitos permitidos incluem Modify, ReadPermissions, e Synchronize. O exemplo cria então uma nova regra para o utilizador atual, incluindo ReadPermissions os direitos and TakeOwnership , e usa essa regra com o RemoveAccessRule método para remover ReadPermissions da Allow regra no MutexSecurity objeto. A direita supérflua TakeOwnershiprule é ignorada.

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 and read the
        // permissions on the mutex.
        MutexAccessRule rule = new MutexAccessRule(user, 
            MutexRights.Synchronize | MutexRights.Modify
                | MutexRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.AddAccessRule(rule);

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

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

        // Create a rule that grants the current user 
        // the right to read permissions on the mutex, and
        // take ownership of the mutex. Use this rule to 
        // remove the right to read permissions from the 
        // Allow rule for the current user. The inclusion 
        // of the right to take ownership has no effect.
        rule = new MutexAccessRule(user, 
            MutexRights.TakeOwnership | 
                MutexRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.RemoveAccessRule(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, ReadPermissions, Synchronize


Current access rules:

        User: TestDomain\TestUser
        Type: Deny
      Rights: ChangePermissions

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

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, and to 
        ' read its permissions.
        Dim rule As New MutexAccessRule(user, _
            MutexRights.Synchronize _
            Or MutexRights.Modify _
            Or MutexRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.AddAccessRule(rule)

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

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

        ' Create a rule that grants the current user 
        ' the right to read permissions on the mutex, and
        ' take ownership of the mutex. Use this rule to 
        ' remove the right to read permissions from the 
        ' Allow rule for the current user. The inclusion 
        ' of the right to take ownership has no effect.
        rule = New MutexAccessRule(user, _
            MutexRights.TakeOwnership _
            Or MutexRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.RemoveAccessRule(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, ReadPermissions, Synchronize
'
'
'Current access rules:
'
'        User: TestDomain\TestUser
'        Type: Deny
'      Rights: ChangePermissions
'
'        User: TestDomain\TestUser
'        Type: Allow
'      Rights: Modify, Synchronize

Observações

A corrente MutexSecurity é pesquisada por uma regra que tenha o mesmo utilizador e o mesmo AccessControlType valor que rule. Se tal regra não for encontrada, nenhuma ação é tomada, e o método devolve false. Se forem encontradas regras correspondentes, as suas flags de herança e compatibilidade são verificadas quanto à compatibilidade com as flags especificadas em rule. Se não for encontrada regra compatível, não é tomada qualquer ação e o método devolve false. Se for encontrada uma regra com flags compatíveis, os direitos especificados em rule são removidos da regra compatível, e o método devolve true. Se rule especificar direitos não contidos na regra compatível, não é tomada qualquer ação relativamente a esses direitos. Se todos os direitos forem removidos da regra compatível, toda a regra é removida do objeto atual MutexSecurity .