EventWaitHandleSecurity.RemoveAccessRule(EventWaitHandleAccessRule) 方法

定義

命名空間:

System.Security.AccessControl

組件:

System.Threading.AccessControl.dll

搜尋具有與指定之存取規則相同的使用者和 AccessControlType (允許或拒絕) 以及具有相容的繼承和傳用旗標的存取控制規則。如果找到這樣的規則，則會移除指定之存取規則中所包含的權限。

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

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

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

Public Function RemoveAccessRule (rule As EventWaitHandleAccessRule) As Boolean

參數

rule

EventWaitHandleAccessRule

EventWaitHandleAccessRule，其會指定要搜尋的使用者和 AccessControlType，以及必須與相符的規則 (如果找到的話) 相容的繼承和傳用旗標集合。 如果找到的話，指定從相容的規則中移除此權限。

傳回

Boolean

如果找到相容的規則，則為 true，否則為 false。

例外狀況

ArgumentNullException

rule 為 null。

範例

下列程式代碼範例示範如何使用 RemoveAccessRule 方法，從 Allow 物件中的 EventWaitHandleSecurity 規則移除許可權。 它也會顯示 中 rule 其他許可權會被忽略。

此範例會 EventWaitHandleSecurity 建立 物件，並新增規則，以允許和拒絕目前使用者的各種許可權。 允許的權限包括 Modify、 ReadPermissions與 Synchronize。 此範例接著會為目前使用者建立新的規則，包括 ReadPermissions 和許可權，並使用該規則搭配 RemoveAccessRule 方法從 Allow 物件中的EventWaitHandleSecurity規則中移除ReadPermissionsTakeOwnership。 TakeOwnership中的rule右邊會被忽略。

注意

這個範例不會將安全性物件附加至 EventWaitHandle 物件。 您可以在和 EventWaitHandle.SetAccessControl中找到EventWaitHandle.GetAccessControl附加安全性物件的範例。

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 and read the
        // permissions on the event.
        EventWaitHandleAccessRule rule = new EventWaitHandleAccessRule(user, 
            EventWaitHandleRights.Synchronize | EventWaitHandleRights.Modify
                | EventWaitHandleRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.AddAccessRule(rule);

        // Add a rule that denies the current user the 
        // right to change permissions on the event.
        rule = new EventWaitHandleAccessRule(user, 
            EventWaitHandleRights.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 event, and
        // take ownership of the event. 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 EventWaitHandleAccessRule(user, 
            EventWaitHandleRights.TakeOwnership | 
                EventWaitHandleRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.RemoveAccessRule(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, 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 EventWaitHandleSecurity()

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

        ' Add a rule that denies the current user the 
        ' right to change permissions on the event.
        rule = New EventWaitHandleAccessRule(user, _
            EventWaitHandleRights.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 event, and
        ' take ownership of the event. 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 EventWaitHandleAccessRule(user, _
            EventWaitHandleRights.TakeOwnership _
            Or EventWaitHandleRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.RemoveAccessRule(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, ReadPermissions, Synchronize
'
'
'Current access rules:
'
'        User: TestDomain\TestUser
'        Type: Deny
'      Rights: ChangePermissions
'
'        User: TestDomain\TestUser
'        Type: Allow
'      Rights: Modify, Synchronize

備註

目前 EventWaitHandleSecurity 會搜尋具有相同使用者和相同 AccessControlType 值 rule的規則。 如果找不到這類規則，則不會採取任何動作，而且方法會傳 false回 。 如果找到相符的規則，則會檢查其繼承和相容性旗標是否與 中指定的 rule旗標相容。 如果找不到相容的規則，則不會採取任何動作，而且方法會傳 false回 。 如果找到具有相容旗標的規則，則會從相容的規則中移除中指定的 rule 許可權，而 方法會傳 true回 。 如果 rule 指定不相容規則中未包含的許可權，則不會針對這些許可權採取任何動作。 如果從相容規則中移除所有許可權，則會從目前的 EventWaitHandleSecurity 物件中移除整個規則。

重要

雖然您可以使用 方法來建立事件存取規則，以指定事件存取規則的 AccessRuleFactory 繼承和傳播旗標，但不建議這麼做。 繼承和傳播對具名事件沒有任何意義，而且它們會使存取規則的維護變得更複雜。