IsolatedStorageFilePermissionAttribute Class
Allows security actions for IsolatedStorageFilePermission to be applied to code using declarative security. This class cannot be inherited.
Assembly: mscorlib (in mscorlib.dll)
'Declaration <SerializableAttribute> _ <ComVisibleAttribute(True)> _ <AttributeUsageAttribute(AttributeTargets.Assembly Or AttributeTargets.Class Or AttributeTargets.Struct Or AttributeTargets.Constructor Or AttributeTargets.Method, AllowMultiple := True, _ Inherited := False)> _ Public NotInheritable Class IsolatedStorageFilePermissionAttribute _ Inherits IsolatedStoragePermissionAttribute 'Usage Dim instance As IsolatedStorageFilePermissionAttribute
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.
The following example of a declarative attribute shows the correct way to request IsolatedStorageFilePermission, states that you must have at least this permission to run your code, and requests a maximum user quota of 5 MB.
The following example shows how to demand that the calling code has unrestricted IsolatedStorageFilePermission at link time. Demands are typically made in managed libraries (DLLs) to help protect methods or classes from potentially harmful code.
This example shows how to tell the CLR that code in this assembly requires the IsolatedStoragePermission and also demonstrates how to write and read from isolated storage.
Option Strict On Imports System Imports System.Security.Permissions Imports System.IO.IsolatedStorage Imports System.IO ' Notify the CLR to only grant IsolatedStorageFilePermission to called methods. ' This restricts the called methods to working only with storage files that are isolated ' by user and assembly. <IsolatedStorageFilePermission(SecurityAction.PermitOnly, UsageAllowed:=IsolatedStorageContainment.AssemblyIsolationByUser)> _ Public NotInheritable Class App Shared Sub Main() WriteIsolatedStorage() End Sub 'Main Shared Sub WriteIsolatedStorage() ' Attempt to create a storage file that is isolated by user and assembly. ' IsolatedStorageFilePermission granted to the attribute at the top of this file ' allows CLR to load this assembly and execution of this statement. Dim s As New IsolatedStorageFileStream("AssemblyData", FileMode.Create, IsolatedStorageFile.GetUserStoreForAssembly()) Try ' Write some data out to the isolated file. Dim sw As New StreamWriter(s) Try sw.Write("This is some test data.") Finally sw.Dispose() End Try Finally s.Dispose() End Try ' Attempt to open the file that was previously created. Dim t As New IsolatedStorageFileStream("AssemblyData", FileMode.Open, IsolatedStorageFile.GetUserStoreForAssembly()) Try ' Read the data from the file and display it. Dim sr As New StreamReader(t) Try Console.WriteLine(sr.ReadLine()) Finally sr.Dispose() End Try Finally t.Dispose() End Try End Sub End Class 'App ' This code produces the following output. ' ' Some test data.
System.Attribute
System.Security.Permissions.SecurityAttribute
System.Security.Permissions.CodeAccessSecurityAttribute
System.Security.Permissions.IsolatedStoragePermissionAttribute
System.Security.Permissions.IsolatedStorageFilePermissionAttribute
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.