MutexSecurity.SetAccessRule(MutexAccessRule) Method
Definition
Important
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Removes all access control rules with the same user and AccessControlType (allow or deny) as the specified rule, and then adds the specified rule.
public:
void SetAccessRule(System::Security::AccessControl::MutexAccessRule ^ rule);public void SetAccessRule (System.Security.AccessControl.MutexAccessRule rule);override this.SetAccessRule : System.Security.AccessControl.MutexAccessRule -> unitPublic Sub SetAccessRule (rule As MutexAccessRule)Parameters
- rule
- MutexAccessRule
The MutexAccessRule to add. The user and AccessControlType of this rule determine the rules to remove before this rule is added.
Exceptions
rule is null.
Examples
The following code example shows how the SetAccessRule method removes all rules that match both the user and the AccessControlType of rule, replacing them with rule.
The example creates a MutexSecurity object and adds rules that allow and deny various rights for the current user. The example then creates a new rule that allows the current user full control, and uses the SetAccessRule method to replace the existing Allow rule with the new rule. The rule that denies access is not affected.
Note
This example does not attach the security object to a Mutex object. Examples that attach security objects can be found in Mutex.GetAccessControl and Mutex.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.
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 full control over the mutex. Use the
// SetAccessRule method to replace the
// existing Allow rule with the new rule.
rule = new MutexAccessRule(user,
MutexRights.FullControl,
AccessControlType.Allow);
mSec.SetAccessRule(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: FullControl
*/
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 full control over the mutex. Use the
' SetAccessRule method to replace the
' the existing Allow rule with the new rule.
rule = New MutexAccessRule(user, _
MutexRights.FullControl, _
AccessControlType.Allow)
mSec.SetAccessRule(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: FullControl
Remarks
If the specified rule has Allow, the effect of this method is to remove all Allow rules for the specified user, replacing them with the specified rule. If the specified rule has Deny, all Deny rules for the specified user are replaced with the specified rule.
If there are no rules whose user and AccessControlType match the specified rule, rule is added.
