MutexSecurity.RemoveAccessRule(MutexAccessRule) 方法

定義

命名空間:

System.Security.AccessControl

組件:

System.Threading.AccessControl.dll

套件:

System.Threading.AccessControl v8.0.0

來源:

MutexSecurity.cs

搜尋具有與指定之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::MutexAccessRule ^ rule);

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

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

Public Function RemoveAccessRule (rule As MutexAccessRule) As Boolean

參數

rule

MutexAccessRule

MutexAccessRule，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

下列程式碼範例示範如何使用 RemoveAccessRule 方法，從 Allow 物件中的 MutexSecurity 規則中移除許可權。 它也會顯示 中其他許可權 rule 會被忽略。

此範例會 MutexSecurity 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。 允許的許可權包括 Modify 、 ReadPermissions 和 Synchronize 。 然後，此範例會為目前使用者建立新的規則，包括 ReadPermissions 和 許可權，並將該規則與 方法搭配 RemoveAccessRule 使用，以從 Allow 物件中的 MutexSecurity 規則中移除 ReadPermissionsTakeOwnership 。 會忽略 中的 rule 不適當 TakeOwnership 許可權。

注意

這個範例不會將安全性物件附加至 Mutex 物件。 您可以在 和 Mutex.SetAccessControl 中找到 Mutex.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.
        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 right to read permissions on the mutex, and
        // take ownership of the mutex. 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 MutexAccessRule(user, 
            MutexRights.TakeOwnership | 
                MutexRights.ReadPermissions, 
            AccessControlType.Allow);
        mSec.RemoveAccessRule(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: 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 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 right to read permissions on the mutex, and
        ' take ownership of the mutex. 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 MutexAccessRule(user, _
            MutexRights.TakeOwnership _
            Or MutexRights.ReadPermissions, _
            AccessControlType.Allow)
        mSec.RemoveAccessRule(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: Modify, Synchronize

備註

目前 MutexSecurity 會搜尋具有相同使用者的規則，以及與 rule 相同的 AccessControlType 值。 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擁有權限，則會從目前的 MutexSecurity 物件中移除整個規則。

重要

雖然您可以指定 mutex 存取規則的繼承和傳播旗標，但建議使用 方法建立它們 AccessRuleFactory 。 繼承和傳播對具名 Mutex 沒有任何意義，而且它們會使存取規則的維護更為複雜。