FileIOPermissionAttribute Class
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FileIOPermissionAttribute Class


Allows security actions for FileIOPermission to be applied to code using declarative security. This class cannot be inherited.

Namespace:   System.Security.Permissions
Assembly:  mscorlib (in mscorlib.dll)


[AttributeUsageAttribute(AttributeTargets.Assembly | AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Constructor | AttributeTargets.Method, 
	AllowMultiple = true, Inherited = false)]
public sealed class FileIOPermissionAttribute : CodeAccessSecurityAttribute


Initializes a new instance of the FileIOPermissionAttribute class with the specified SecurityAction.


Gets or sets a security action.(Inherited from SecurityAttribute.)


Obsolete.Gets or sets full access for the file or directory that is specified by the string value.


Gets or sets the permitted access to all files.


Gets or sets the permitted access to all local files.


Gets or sets append access for the file or directory that is specified by the string value.


Gets or sets the file or directory in which access control information can be changed.


Gets or sets the file or directory to which to grant path discovery.


Gets or sets read access for the file or directory specified by the string value.


When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)


Gets or sets a value indicating whether full (unrestricted) permission to the resource protected by the attribute is declared.(Inherited from SecurityAttribute.)


Gets or sets the file or directory in which access control information can be viewed.


Gets or sets the file or directory in which file data can be viewed and modified.


Gets or sets write access for the file or directory specified by the string value.


Creates and returns a new FileIOPermission.(Overrides SecurityAttribute.CreatePermission().)


This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)


Returns the hash code for this instance.(Inherited from Attribute.)


Gets the Type of the current instance.(Inherited from Object.)


When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)


When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)


Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)


Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

Files and directories are specified using absolute paths. When accessing files, a security check is performed when the file is created or opened. The security check is not done again unless the file is closed and reopened. Checking permissions when the file is first accessed minimizes the impact of the security check on application performance because opening a file happens only once, while reading and writing can happen multiple times.

The scope of the declaration that is allowed depends on the SecurityAction that is used.

The security information declared by a security attribute is stored in the metadata of the attribute target and is accessed by the system at run time. Security attributes are used only for declarative security. For imperative security, use the corresponding permission class.


UnrestrictedFileIOPermission grants permission for all paths within a file system, including multiple pathnames that can be used to access a single given file. To Deny access to a file, you must Deny all possible paths to the file. For example, if \\server\share is mapped to the network drive X, to Deny access to \\server\share\file, you must Deny \\server\share\file, X:\file and any other path that you can use to access the file.

The following code example demonstrates how to request FileIOPermission by using the FileIOPermissionAttribute class, indicating the only permission that is to be granted to the code.

[FileIOPermissionAttribute(SecurityAction.PermitOnly, ViewAndModify = "C:\\example\\sample.txt")]

The following example shows how to demand that the calling code has unrestricted FileIOPermission. You typically make demands in managed libraries (DLLs) to help protect methods or classes from potentially harmful code.

[FileIOPermissionAttribute(SecurityAction.Demand, Unrestricted=true)]

.NET Framework
Available since 1.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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