File.SetAccessControl Method (String, FileSecurity)


Applies access control list (ACL) entries described by a FileSecurity object to the specified file.

Namespace:   System.IO
Assembly:  mscorlib (in mscorlib.dll)

static member SetAccessControl : 
        path:string *
        fileSecurity:FileSecurity -> unit


Type: System.String

A file to add or remove access control list (ACL) entries from.

Type: System.Security.AccessControl.FileSecurity

A FileSecurity object that describes an ACL entry to apply to the file described by the path parameter.

Exception Condition

An I/O error occurred while opening the file.


The path parameter is null.


The file could not be found.


The path parameter specified a file that is read-only.


This operation is not supported on the current platform.


The path parameter specified a directory.


The caller does not have the required permission.


The fileSecurity parameter is null.

The SetAccessControl method applies access control list (ACL) entries to a file that represents the noninherited ACL list.


The ACL specified for the fileSecurity parameter replaces the existing ACL for the file. To add permissions for a new user, use the GetAccessControl method to obtain the existing ACL, modify it, and then use SetAccessControl to apply it back to the file.

An ACL describes individuals and/or groups who have, or do not have, rights to specific actions on the given file. For more information, see How to: Add or Remove Access Control List Entries.

The SetAccessControl method persists only FileSecurity objects that have been modified after object creation.  If a FileSecurity object has not been modified, it will not be persisted to a file.  Therefore, it is not possible to retrieve a FileSecurity object from one file and reapply the same object to another file.

To copy ACL information from one file to another:

  1. Use the GetAccessControl method to retrieve the FileSecurity object from the source file.

  2. Create a new FileSecurity object for the destination file.

  3. Use the GetSecurityDescriptorBinaryForm or GetSecurityDescriptorSddlForm method of the source FileSecurity object to retrieve the ACL information.

  4. Use the SetSecurityDescriptorBinaryForm or SetSecurityDescriptorSddlForm method to copy the information retrieved in step 3 to the destination FileSecurity object.

  5. Set the destination FileSecurity object to the destination file using the SetAccessControl method.

In NTFS environments, ReadAttributes and ReadExtendedAttributes are granted to the user if the user has ListDirectory rights on the parent folder. To deny ReadAttributes and ReadExtendedAttributes, deny ListDirectory on the parent directory.

The following code example uses the GetAccessControl and SetAccessControl methods to add and then remove an access control list (ACL) entry from a file. You must supply a valid user or group account to run this example.

No code example is currently available or this language may not be supported.


for permission to access the file. Security action: Demand. Associated enumerations: FileIOPermissionAccess.NoAccess, AccessControlActions.Change

.NET Framework
Available since 2.0
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