SemaphoreSecurity.RemoveAccessRuleSpecific(SemaphoreAccessRule) Methode

Definition

Sucht nach einer Zugriffssteuerungsregel, die exakt der angegebenen Regel entspricht, und entfernt sie, falls gefunden,.

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

Die zu entfernende Option SemaphoreAccessRule .

Ausnahmen

rule ist null.

Beispiele

Das folgende Codebeispiel zeigt, dass für die RemoveAccessRuleSpecific Methode eine genaue Übereinstimmung erforderlich ist, um eine Regel zu entfernen, und dass regeln, um Rechte zuzulassen und zu verweigern, voneinander unabhängig sind.

Das Beispiel erstellt ein SemaphoreSecurity Objekt, fügt Regeln hinzu, die verschiedene Rechte für den aktuellen Benutzer zulassen und verweigern, und führt dann zusätzliche Rechte in die Allow Zugriffsregel ein. Anschließend übergibt das Beispiel die ursprüngliche Allow Regel an die RemoveAccessRuleSpecific Methode und zeigt die Ergebnisse an, die zeigen, dass nichts gelöscht wird. Anschließend erstellt das Beispiel eine Regel, die der Allow Regel im SemaphoreSecurity Objekt entspricht, und verwendet die RemoveAccessRuleSpecific Methode erfolgreich, um die Regel zu entfernen.

Note

In diesem Beispiel wird das Sicherheitsobjekt nicht an ein Semaphore Objekt angefügt. Beispiele zum 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.

Important

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

Gilt für: