EventWaitHandleSecurity.RemoveAccessRuleSpecific Metoda

Definice

Obor názvů:

System.Security.AccessControl

Sestavení:

System.Threading.AccessControl.dll

Balíček:

System.Threading.AccessControl v9.0.0-rc.2.24473.5

Zdroj:

EventWaitHandleSecurity.cs

Vyhledá pravidlo řízení přístupu, které přesně odpovídá zadanému pravidlu, a pokud ho najde, odebere ho.

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

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

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

Public Sub RemoveAccessRuleSpecific (rule As EventWaitHandleAccessRule)

Parametry

rule

EventWaitHandleAccessRule

Chcete-li EventWaitHandleAccessRule odebrat.

Výjimky

ArgumentNullException

rule je null.

Příklady

Následující příklad kódu ukazuje, že RemoveAccessRuleSpecific metoda vyžaduje přesnou shodu, aby bylo možné pravidlo odebrat, a že pravidla pro povolení a odepření práv jsou na sobě nezávislá.

Příklad vytvoří EventWaitHandleSecurity objekt, přidá pravidla, která povolují a zamítnou různá práva pro aktuálního uživatele, a pak sloučí další práva do Allow pravidla přístupu. Příklad pak předá původní Allow pravidlo RemoveAccessRuleSpecific metodě a zobrazí výsledky, které ukazují, že nic není odstraněno. Příklad pak vytvoří pravidlo, které odpovídá pravidlu Allow v objektu EventWaitHandleSecurity , a úspěšně použije metodu RemoveAccessRuleSpecific k odebrání pravidla.

Poznámka

Tento příklad nepřipoutuje objekt zabezpečení k objektu EventWaitHandle . Příklady, které připojují objekty zabezpečení, najdete v EventWaitHandle.GetAccessControl a EventWaitHandle.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.
        EventWaitHandleSecurity mSec = new EventWaitHandleSecurity();

        // Add a rule that grants the current user the 
        // right to wait on or signal the event.
        EventWaitHandleAccessRule ruleA = new EventWaitHandleAccessRule(user, 
            EventWaitHandleRights.Synchronize | EventWaitHandleRights.Modify, 
            AccessControlType.Allow);
        mSec.AddAccessRule(ruleA);

        // Add a rule that denies the current user the 
        // right to change permissions on the event.
        EventWaitHandleAccessRule rule = new EventWaitHandleAccessRule(user, 
            EventWaitHandleRights.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 event. This rule
        // is merged with the existing Allow rule.
        rule = new EventWaitHandleAccessRule(user, 
            EventWaitHandleRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.AddAccessRule(rule);

        ShowSecurity(mSec);

        // Attempt to remove the original rule (granting
        // the right to wait on or signal the event) with 
        // RemoveAccessRuleSpecific. The removal fails,
        // because the right to read the permissions on the 
        // event 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 wait on or signal the event, 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 EventWaitHandleAccessRule(user, 
            EventWaitHandleRights.Synchronize | EventWaitHandleRights.Modify | 
                EventWaitHandleRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.RemoveAccessRuleSpecific(rule);

        ShowSecurity(mSec);
    }

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

        foreach(EventWaitHandleAccessRule 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.EventWaitHandleRights);
            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 EventWaitHandleSecurity()

        ' Add a rule that grants the current user the 
        ' right to wait on or signal the event.
        Dim ruleA As New EventWaitHandleAccessRule(user, _
            EventWaitHandleRights.Synchronize _
            Or EventWaitHandleRights.Modify, _
            AccessControlType.Allow)
        mSec.AddAccessRule(ruleA)

        ' Add a rule that denies the current user the 
        ' right to change permissions on the event.
        Dim rule As New EventWaitHandleAccessRule(user, _
            EventWaitHandleRights.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 event. This rule
        ' is merged with the existing Allow rule.
        rule = New EventWaitHandleAccessRule(user, _
            EventWaitHandleRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.AddAccessRule(rule)

        ShowSecurity(mSec)

        ' Attempt to remove the original rule (granting
        ' the right to wait on or signal the event) with 
        ' RemoveAccessRuleSpecific. The removal fails,
        ' because the right to read the permissions on the 
        ' event 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 wait on or signal the event, 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 EventWaitHandleAccessRule(user, _
            EventWaitHandleRights.Synchronize _
            Or EventWaitHandleRights.Modify _
            Or EventWaitHandleRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.RemoveAccessRuleSpecific(rule)

        ShowSecurity(mSec)
        
    End Sub 

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

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

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

Poznámky

Pravidlo se odebere jenom v případě, že přesně odpovídá rule všem podrobnostem, včetně příznaků. Další pravidla se stejným uživatelem a AccessControlType nejsou ovlivněna.

Důležité

Pravidlo představuje jednu nebo více podkladových položek řízení přístupu (ACE) a tyto položky se rozdělí nebo zkombinují podle potřeby, když upravíte pravidla zabezpečení přístupu pro uživatele. To znamená, že pravidlo už nemusí existovat v konkrétní formě, kterou mělo při přidání, a v takovém případě ho RemoveAccessRuleSpecific metoda nemůže odebrat.