MutexSecurity.SetAccessRule(MutexAccessRule) Método

Definição

Namespace:

System.Security.AccessControl

Assembly:

System.Threading.AccessControl.dll

Remove todas as regras de controle de acesso com o mesmo usuário e AccessControlType (permitir ou negar) que a regra especificada e, em seguida, adiciona a regra especificada.

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

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

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

Public Sub SetAccessRule (rule As MutexAccessRule)

Parâmetros

rule

MutexAccessRule

O MutexAccessRule a ser adicionado. O usuário e o AccessControlType dessa regra determinam as regras a serem removidas antes dessa regra ser adicionada.

Exceções

ArgumentNullException

rule é null.

Exemplos

O exemplo de código a seguir mostra como o SetAccessRule método remove todas as regras que correspondem ao usuário e ao AccessControlType de rule, substituindo-as por rule.

O exemplo cria um MutexSecurity objeto e adiciona regras que permitem e negam vários direitos para o usuário atual. Em seguida, o exemplo cria uma nova regra que permite o controle total do usuário atual e usa o SetAccessRule método para substituir a regra Allow existente pela nova regra. A regra que nega o acesso não é afetada.

Observação

Este exemplo não anexa o objeto de segurança a um Mutex objeto . Exemplos que anexam objetos de segurança podem ser encontrados em Mutex.GetAccessControl e Mutex.SetAccessControl.

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 full control over the mutex. Use the
        // SetAccessRule method to replace the 
        // existing Allow rule with the new rule. 
        rule = new MutexAccessRule(user,
            MutexRights.FullControl,
            AccessControlType.Allow);
        mSec.SetAccessRule(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: FullControl
 */

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 full control over the mutex. Use the
        ' SetAccessRule method to replace the 
        ' the existing Allow rule with the new rule. 
        rule = New MutexAccessRule(user, _
            MutexRights.FullControl, _
            AccessControlType.Allow)
        mSec.SetAccessRule(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: FullControl

Comentários

Se a regra especificada tiver Allow, o efeito desse método será remover todas as Allow regras para o usuário especificado, substituindo-as pela regra especificada. Se a regra especificada tiver Deny, todas as Deny regras para o usuário especificado serão substituídas pela regra especificada.

Se não houver regras cujo usuário e AccessControlType correspondam à regra especificada, rule será adicionado.