SemaphoreSecurity.RemoveAccessRuleSpecific(SemaphoreAccessRule) Methode

Definition

Namespace:

System.Security.AccessControl

Assembly:

System.Threading.AccessControl.dll

Assembly:

System.dll

Sucht nach einer Zugriffssteuerungsregel, die genau mit der angegebenen Regel übereinstimmt, und entfernt diese (falls vorhanden).

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

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

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

Public Sub RemoveAccessRuleSpecific (rule As SemaphoreAccessRule)

Parameter

rule

SemaphoreAccessRule

Das zu entfernende SemaphoreAccessRule-Element.

Ausnahmen

ArgumentNullException

rule ist null.

Beispiele

Im folgenden Codebeispiel wird gezeigt, dass die RemoveAccessRuleSpecific Methode eine genaue Übereinstimmung erfordert, um eine Regel zu entfernen, und diese Regeln zum Zulassen und Ablehnen von Rechten sind unabhängig voneinander.

Im Beispiel wird ein SemaphoreSecurity Objekt erstellt, Regeln hinzugefügt, die verschiedene Rechte für den aktuellen Benutzer zulassen und ablehnen und dann zusätzliche Rechte in die Allow Zugriffsregel zusammenführen. Im Beispiel wird dann die ursprüngliche Allow Regel an die RemoveAccessRuleSpecific Methode übergeben und die Ergebnisse angezeigt, die zeigen, dass nichts gelöscht wird. Im Beispiel wird dann eine Regel erstellt, die Allow der Regel im SemaphoreSecurity Objekt entspricht und die Methode erfolgreich verwendet, um die RemoveAccessRuleSpecific Regel zu entfernen.

Hinweis

In diesem Beispiel wird das Sicherheitsobjekt nicht an ein Semaphore Objekt angefügt. Beispiele für die Anfügen von Sicherheitsobjekten finden Sie in Semaphore.GetAccessControl und Semaphore.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.
        SemaphoreSecurity mSec = new SemaphoreSecurity();

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

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

        ShowSecurity(mSec);

        // Attempt to remove the original rule (granting
        // the right to enter or release the semaphore) with 
        // RemoveAccessRuleSpecific. The removal fails,
        // because the right to read the permissions on the 
        // semaphore 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 semaphore, 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 SemaphoreAccessRule(user, 
            SemaphoreRights.Synchronize | SemaphoreRights.Modify | 
                SemaphoreRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.RemoveAccessRuleSpecific(rule);

        ShowSecurity(mSec);
    }

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

        foreach(SemaphoreAccessRule 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.SemaphoreRights);
            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 SemaphoreSecurity()

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

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

        ShowSecurity(mSec)

        ' Attempt to remove the original rule (granting
        ' the right to enter or release the semaphore) with 
        ' RemoveAccessRuleSpecific. The removal fails,
        ' because the right to read the permissions on the 
        ' semaphore 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 semaphore, 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 SemaphoreAccessRule(user, _
            SemaphoreRights.Synchronize _
            Or SemaphoreRights.Modify _
            Or SemaphoreRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.RemoveAccessRuleSpecific(rule)

        ShowSecurity(mSec)
        
    End Sub 

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

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

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

Hinweise

Die Regel wird nur entfernt, wenn sie genau mit allen Details übereinstimmt rule , einschließlich Flags. Andere Regeln mit demselben Benutzer und AccessControlType sind nicht betroffen.

Wichtig

Eine Regel stellt eine oder mehrere zugrunde liegende Zugriffssteuerungseinträge (ACE) dar, und diese Einträge werden nach Bedarf geteilt oder kombiniert, wenn Sie die Zugriffssicherheitsregeln für einen Benutzer ändern. Daher kann eine Regel möglicherweise nicht mehr in der spezifischen Form vorhanden sein, die sie beim Hinzufügen hatte, und in diesem Fall kann die RemoveAccessRuleSpecific Methode sie nicht entfernen.