IsolatedStorageFilePermission Class
Assembly: mscorlib (in mscorlib.dll)
'Declaration <SerializableAttribute> _ <ComVisibleAttribute(True)> _ Public NotInheritable Class IsolatedStorageFilePermission Inherits IsolatedStoragePermission 'Usage Dim instance As IsolatedStorageFilePermission
/** @attribute SerializableAttribute() */ /** @attribute ComVisibleAttribute(true) */ public final class IsolatedStorageFilePermission extends IsolatedStoragePermission
SerializableAttribute ComVisibleAttribute(true) public final class IsolatedStorageFilePermission extends IsolatedStoragePermission
The common language runtime (CLR) uses this class to control access to isolated storage.
Isolated storage creates a unique storage area for use by an application or component. It provides true isolation in that the identity of an application uniquely determines the root of a virtual file system, which only that application can access. Thus, each application has its own file area automatically assigned to it. This file area is fully isolated from other applications, making it private to that application.
Note |
|---|
| There is no effect if you use Assert, PermitOnly, or Deny to add stack modifiers for usage or quota. Usage and quota are determined from evidence and a stack walk is not performed for demands, making the above operations ineffective. |
The following example shows the use of members of the IsolatedStorageFilePermission class.
Imports System Imports System.Security Imports System.IO Imports System.IO.IsolatedStorage Imports System.Security.Permissions Imports System.Diagnostics Public Class Demo ' Main method. Public Sub Run() Try Copy_EqualsDemo() To_FromXmlDemo() GetTypeDemo() IntersectDemo() UnionDemo() ToStringDemo() Demand_DenyDemo() PermitOnlyDemo() UserQuota_UsageDemo() IsSubsetOfDemo() IsUnrestrictedDemo() Catch e As Exception Console.WriteLine((ControlChars.Cr + ControlChars.Lf + ControlChars.Lf + "The demo failed due to an unexpected exception" + ControlChars.Cr + ControlChars.Lf + e.ToString())) End Try End Sub 'Run ' IsUnrestrictedDemo demonstrates the IsolatedStorageFilePermission.IsUnrestricted method. ' IsUnrestrictedDemo displays a comment indicating whether the current permission is unrestricted. Private Sub IsUnrestrictedDemo() Console.WriteLine("IsUnrestricted demo.") Try Dim isfp As New IsolatedStorageFilePermission(PermissionState.Unrestricted) isfp.Demand() ' The permission should be unrestricted. Console.WriteLine("Created and demanded the IsolatedStorageFilePermission(PermissionState.Unrestricted)permission.") If True <> isfp.IsUnrestricted() Then Console.WriteLine("IsUnrestricted demo failed. The IsUnrestricted property value should be 'true'") End If isfp = New IsolatedStorageFilePermission(PermissionState.None) isfp.Demand() ' The permission should not be unrestricted. Console.WriteLine("Created and demanded the IsolatedStorageFilePermission(PermissionState.None)permission.") If False <> isfp.IsUnrestricted() Then Console.WriteLine("IsUnrestricted demo failed. The IsUnrestricted property value should be 'false'") End If Catch e As Exception Console.WriteLine(("Unexpected exception: " + e.Message)) End Try End Sub 'IsUnrestrictedDemo ' Copy_EqualsDemo demonstrates the Copy and Equals methods. ' Copy creates and returns an identical copy of the current permission. ' Equals compares two permissions and determines whether they are equal. Private Sub Copy_EqualsDemo() Console.WriteLine(ControlChars.Lf + "Copy_Equals demo.") Console.WriteLine("Creating the first IsolatedStorageFilePermission(PermissionState.Unrestricted) permission.") Dim first As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Console.WriteLine(("Hashcode for the first permission : " + first.GetHashCode().ToString())) Console.WriteLine("Copying the first permission.") Dim copyOfFirst As IsolatedStorageFilePermission = CType(first.Copy(), IsolatedStorageFilePermission) Console.WriteLine(("Hashcode for copy of the first permission: " + copyOfFirst.GetHashCode().ToString())) If False = copyOfFirst.Equals(first) Then ' This should be false, because the object references are different. Console.WriteLine(("The copy and the first permission should not be equal because they have " + ControlChars.Lf + ControlChars.Tab + "different object references.")) Else Console.WriteLine(("Error: the copy and the first permission should not be equal because they have " + ControlChars.Lf + ControlChars.Tab + "different object references.")) End If Console.WriteLine(("Does a comparison of copy of first permission to itself test equal??: " + IIf(copyOfFirst.Equals(copyOfFirst), "true", "false"))) If False = copyOfFirst.Equals(copyOfFirst) Then Console.WriteLine("Copy_Equals demo failed because Equals returns false on two object.Equals(itself).") End If Console.WriteLine(("Does a comparison of first permission to itself test equal?: " + IIf(first.Equals(first), "true", "false"))) If False = first.Equals(first) Then Console.WriteLine("Copy_Equals demo failed, because Equals returns false on two object.Equals(itself).") End If Console.WriteLine("Creating a second permission with PermissionState.None.") Dim second As New IsolatedStorageFilePermission(PermissionState.None) Console.WriteLine(("Does the first permission equal the second permission?: " + IIf(first.Equals(second), "true", "false"))) If True = first.Equals(second) Then Console.WriteLine("Copy_Equals demo failed because Equals returns false on two object.Equals(itself).") End If End Sub 'Copy_EqualsDemo ' To_FromXmlDemo demonstrates ToXml and FromXml. ' ToXml creates an XML encoding of the permission and its current state. ' FromXml reconstructs a permission with a specified state from an XML encoding. Private Sub To_FromXmlDemo() Console.WriteLine(ControlChars.Lf + "To_FromXML demo.") Dim firstPermission As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Console.WriteLine(("First permission: " + firstPermission.ToString())) Dim se As SecurityElement = firstPermission.ToXml() Dim secondPermission As New IsolatedStorageFilePermission(PermissionState.None) Console.WriteLine(("Second permission: " + secondPermission.ToString())) secondPermission.FromXml(se) Dim thirdPermission As IsolatedStorageFilePermission = CType(secondPermission.Intersect(firstPermission), IsolatedStorageFilePermission) Console.WriteLine(("Intersection of first permission and second permission: " + thirdPermission.ToString())) Try If False = thirdPermission.IsUnrestricted() Then Console.WriteLine("To_FromXml demo failed: The ToXml, FromXml roundtrip did not succeed.") End If Catch e As Exception Console.WriteLine("To_FromXml demo failed: An exception was thrown when checking the intersection") Console.WriteLine("of the permissions after the XML roundtrip.") Console.WriteLine(e.ToString()) Console.WriteLine(e.ToString()) End Try End Sub 'To_FromXmlDemo ' GetType demonstrates the GetType method. ' This method returns the type of the current instance. Private Sub GetTypeDemo() Console.WriteLine(ControlChars.Lf + "GetType demo.") Dim isfp As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Dim isfp1 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) If 0 <> isfp.GetType().ToString().CompareTo("System.Security.Permissions.IsolatedStorageFilePermission") Then Console.WriteLine(("GetType returned the wrong value: " + isfp.GetType().ToString())) Else Console.WriteLine(("GetType returned: " + isfp.GetType().ToString())) End If End Sub 'GetTypeDemo ' IntersectDemo demonstrates the Intersect method. ' CIntersect creates and returns a permission that is the intersection of the current permission ' and the specified permission. ' Note The intersection of two PermissionState.None permissions *IS* null. Private Sub IntersectDemo() Console.WriteLine(ControlChars.Lf + "Intersect demo.") Dim isfp0 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Dim isfp1 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Dim isfp2 As New IsolatedStorageFilePermission(PermissionState.None) Dim isfp3 As New IsolatedStorageFilePermission(PermissionState.None) Dim t As IsolatedStorageFilePermission = CType(isfp0.Intersect(isfp1), IsolatedStorageFilePermission) If True = t.IsUnrestricted() Then Console.WriteLine("The intersection of two PermissionState.Unrestricted permissions is unrestricted.") Else Console.WriteLine(("Intersect demo failed because the intersection of two unrestricted permissions " + ControlChars.Lf + ControlChars.Tab + "should be unrestricted.")) End If t = CType(isfp0.Intersect(isfp2), IsolatedStorageFilePermission) If False = t.IsUnrestricted() Then Console.WriteLine(("The intersection of a PermissionState.Unrestricted and " + ControlChars.Lf + ControlChars.Tab + "PermissionState.None permission is not unrestricted.")) Else Console.WriteLine(("Intersect demo failed because the intersection of a unrestricted and " + ControlChars.Lf + ControlChars.Tab + "none permission should be none.")) End If ' The permission set that comes back from this intersection is null. t = CType(isfp2.Intersect(isfp3), IsolatedStorageFilePermission) If Nothing Is t Then Console.WriteLine("The intersection of two PermissionState.None permissions is null.") Else Console.WriteLine(("Intersect failed because the intersection of two PermissionState.None permissions " + ControlChars.Lf + ControlChars.Tab + "should be null.")) End If End Sub 'IntersectDemo ' UnionDemo demonstrates the Union method. ' Union creates a permission that is the union of the current permission and the specified permission. ' Note: The union of two PermissionState.None permissions is *NOT* null. Private Sub UnionDemo() Console.WriteLine(ControlChars.Lf + "Union demo.") Dim isfp0 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Dim isfp1 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Dim isfp2 As New IsolatedStorageFilePermission(PermissionState.None) Dim isfp3 As New IsolatedStorageFilePermission(PermissionState.None) Dim t As IsolatedStorageFilePermission = CType(isfp0.Union(isfp1), IsolatedStorageFilePermission) If True = t.IsUnrestricted() Then Console.WriteLine("The union of two PermissionState.Unrestricted permissions is unrestricted.") Else Console.WriteLine(("Union demo failed because the union of two PermissionState.Unrestricted permissions " + ControlChars.Lf + ControlChars.Tab + "should be unrestricted")) End If t = CType(isfp0.Union(isfp2), IsolatedStorageFilePermission) If True = t.IsUnrestricted() Then Console.WriteLine(("The union of a PermissionState.Unrestricted and a PermissionState.None " + ControlChars.Lf + ControlChars.Tab + "permission is unrestricted.")) Else Console.WriteLine(("Union demo failed because the union of a PermissionState.Unrestricted and a " + ControlChars.Lf + ControlChars.Tab + "PermissionState.None permission should be unrestricted.")) End If t = CType(isfp2.Union(isfp3), IsolatedStorageFilePermission) If Nothing Is t Then Console.WriteLine("Union failed because the union of two PermissionState.None permissions should not be null.") Console.WriteLine(t.ToString()) Else Console.WriteLine("The union of two PermissionState.None permissions is none.") End If End Sub 'UnionDemo ' ToStringDemo demonstrates the ToString method. ' ToString creates and returns a string representation of the current permission object. Private Sub ToStringDemo() Console.WriteLine(ControlChars.Lf + "ToString demo.") Dim isfp0 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Dim PermString As [String] = isfp0.ToString() Dim PermStringParts As [String]() = {"class=", "mscorlib", "Version=", "Culture=", "PublicKeyToken=", "version=", "Unrestricted="} Dim part As [String] For Each part In PermStringParts If PermString.IndexOf(part) >= 0 Then Console.WriteLine((part + " found in the string.")) Else Console.WriteLine("ToString demo failed because [{0}] was not found.", part) End If Next part End Sub 'ToStringDemo ' Demand_Deny demonstrates Demand and Deny. ' Demand forces a SecurityException at run time if all callers higher in the call stack ' have not been granted the permission specified by the current instance. ' Deny prevents callers higher in the call stack from using the code that calls this method to ' access the resource specified by the current instance. Private Sub Demand_DenyDemo() Console.WriteLine(ControlChars.Lf + "Demand_Deny demo.") Console.WriteLine("Denying a permission with PermissionState.Unrestricted.") Dim isfp0 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) isfp0.Deny() Try Console.WriteLine("Denying permission a second time.") isfp0.Deny() Catch e As SecurityException Console.WriteLine("SecurityException was thrown as expected.") Catch e As Exception Console.WriteLine(("Demand_Deny demo failed because an unexpected exception was thrown" + ControlChars.Lf + ControlChars.Tab + "when making a second call to Deny()" + ControlChars.Cr + ControlChars.Lf + e.ToString())) End Try Console.WriteLine("Reverting the deny.") IsolatedStorageFilePermission.RevertDeny() If 0 <> DoDemand() Then Console.WriteLine("Demand_Deny demo failed because an unexpected exception was thrown during a demand.") End If isfp0.Deny() If 1 <> DoDemand() Then Console.WriteLine("Demand_Deny demo failed because the expected SecurityException was not thrown during a demand.") End If IsolatedStorageFilePermission.RevertDeny() If 0 <> DoDemand() Then Console.WriteLine("Demand_Deny demo failed because an unexpected exception was thrown during a demand.") End If End Sub 'Demand_DenyDemo ' PermitOnly demonstrates the PermitOnly method. ' PermitOnly prevents callers higher in the call stack from using the code that calls this method to ' access all resources except for the resource specified by the current instance. Private Sub PermitOnlyDemo() Console.WriteLine(ControlChars.Lf + "PermitOnly demo.") Dim isfp0 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) isfp0.Demand() isfp0.PermitOnly() Try isfp0.PermitOnly() Catch e As SecurityException Console.WriteLine("The second call to PermitOnly caused an exception as expected.") Catch e As Exception Console.WriteLine(("PermitOnly demo failed because an unexpected exception was thrown" + ControlChars.Lf + ControlChars.Tab + "when making a second call to PermitOnly()" + ControlChars.Cr + ControlChars.Lf + e.ToString())) End Try IsolatedStorageFilePermission.RevertPermitOnly() If 0 <> DemandUI() Then Console.WriteLine("PermitOnly demo failed because an exception was thrown during a demand for UI permissions.") Console.WriteLine("We weren't expecting this.") End If isfp0.PermitOnly() If 1 <> DemandUI() Then Console.WriteLine(("PermitOnly demo failed because a SecurityException was not thrown, " + ControlChars.Lf + ControlChars.Tab + "during a demand for UI permissions. A SecurityException was expected.")) End If IsolatedStorageFilePermission.RevertPermitOnly() If 0 <> DoDemand() Then Console.WriteLine("PermitOnly failed because an exception was thrown during a demand for UI permissions.") Console.WriteLine("We weren't expecting this.") End If End Sub 'PermitOnlyDemo ' UserQuota_UsageDemo demonstrates UserQuota and UsageAllowed properties. ' UserQuota gets or sets the quota on the overall size of each user's total store. ' This property is inherited from IsolatedStoragePermission.UserQuota. ' UsageAllowed gets or sets the type of isolated storage containment allowed. ' This property is inherited from IsolatedStoragePermission.UsageAllowed. ' Note You can set UsageAllowed to None, but you cannot set UserQuota to 0. ' Also note that trying to set UsageAllowed or UserQuota to values that are currently set ' will throw an exception. <IsolatedStorageFilePermissionAttribute(SecurityAction.Deny, _ UsageAllowed:=IsolatedStorageContainment.DomainIsolationByRoamingUser, UserQuota:=100)> _ Private Sub UserQuota_UsageDemo() Console.WriteLine(ControlChars.Lf + "UserQuota_Usage demo.") Dim returnValue As Boolean = False Dim isfp0 As New IsolatedStorageFilePermission(PermissionState.None) Console.WriteLine("Checking UsageAllowed for IsolatedStorageContainment.None") returnValue = UsageAllowed(isfp0, IsolatedStorageContainment.None, False) If Not returnValue Then Console.WriteLine("IsolatedStorageContainment.None demo failed") End If Console.WriteLine("Checking UsageAllowed for IsolatedStorageContainment.DomainIsolationByRoamingUser.") returnValue = UsageAllowed(isfp0, IsolatedStorageContainment.DomainIsolationByRoamingUser, True) If Not returnValue Then Console.WriteLine("IsolatedStorageContainment.DomainIsolationByRoamingUser failed") End If Console.WriteLine("Checking UsageAllowed for IsolatedStorageContainment.AssemblyIsolationByUser.") returnValue = UsageAllowed(isfp0, IsolatedStorageContainment.AssemblyIsolationByUser, True) If Not returnValue Then Console.WriteLine("IsolatedStorageContainment.AssemblyIsolationByUse failed") End If Console.WriteLine("Requesting UserQuota of 0.") returnValue = UserQuota(isfp0, 0, True) If Not returnValue Then Console.WriteLine("UserQuota 0 failed") End If Console.WriteLine("Requesting UserQuota of 100.") returnValue = UserQuota(isfp0, 100, True) If Not returnValue Then Console.WriteLine("UserQuota 100 failed") End If Console.WriteLine("Requesting UserQuota of -2147483648.") returnValue = UserQuota(isfp0, -2147483648, True) If Not returnValue Then Console.WriteLine("UserQuota -214748364 failed") End If End Sub 'UserQuota_UsageDemo ' IsSubsetOfDemo demonstrates the IsSubsetOf method. ' IsSubsetOf determines whether the current permission is a subset of the specified permission. Private Sub IsSubsetOfDemo() Console.WriteLine(ControlChars.Lf + "IsSubsetOf demo.") Dim isfp0 As New IsolatedStorageFilePermission(PermissionState.None) Dim isfp1 As New IsolatedStorageFilePermission(PermissionState.None) Dim isfp2 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Dim isfp3 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) If isfp0.IsSubsetOf(isfp1) Then Console.WriteLine("PermissionState.None is a subset of PermissionState.None.") Else Console.WriteLine("IsSubsetOfDemo failed: PermissionState.None should be a subset of PermissionState.None") End If If isfp0.IsSubsetOf(isfp2) Then Console.WriteLine("PermissionState.None is a subset of PermissionState.Unrestricted.") Else Console.WriteLine("IsSubsetOfDemo failed: PermissionState.None should be a subset of PermissionState.Unrestricted") End If If Not isfp2.IsSubsetOf(isfp0) Then Console.WriteLine("PermissionState.Unrestricted is not a subset of PermissionState.None.") Else Console.WriteLine(("IsSubsetOfDemo failed: PermissionState.Unrestricted should not be a subset " + ControlChars.Lf + ControlChars.Tab + "of PermissionState.None")) End If If isfp2.IsSubsetOf(isfp3) Then Console.WriteLine("PermissionState.Unrestricted is a subset of PermissionState.Unrestricted.") Else Console.WriteLine(("IsSubsetOfDemo failed: Permissionstate.Unrestricted should be a subset of " + ControlChars.Lf + ControlChars.Tab + "PermissionState.Unrestricted")) End If End Sub 'IsSubsetOfDemo ' ********************************************************************** ' The following methods are simple helper functions. ' ********************************************************************** ' ********************************************************************** ' UserQuota ' Sets UserQuota to the value that was passed in. ' Private Function UserQuota(ByVal isfp As IsolatedStorageFilePermission, ByVal user_quota As Integer, ByVal exception_expected As Boolean) As Boolean Dim ExceptionCaught As Boolean = False isfp.UserQuota = user_quota Try isfp.Demand() Catch e As Exception ExceptionCaught = True If Not exception_expected Then Console.WriteLine("An unexpected exception was thrown when setting UserQuota value [{0}]", user_quota.ToString()) Console.WriteLine(("Exception: " + ControlChars.Cr + ControlChars.Lf + e.ToString())) End If End Try If Not ExceptionCaught AndAlso exception_expected Then Console.WriteLine("An expected exception not thrown when setting UserQuota value [{0}]", user_quota.ToString()) End If Return True End Function 'UserQuota ' ********************************************************************** ' UsageAllowed ' This method sets UsageAllowed to the value that was passed in. ' Private Function UsageAllowed(ByVal isfp As IsolatedStorageFilePermission, ByVal isc As IsolatedStorageContainment, ByVal exception_expected As Boolean) As Boolean Dim ExceptionCaught As Boolean = False isfp.UsageAllowed = isc Try isfp.Demand() Catch e As Exception ExceptionCaught = True If Not exception_expected Then Console.WriteLine("An unexpected exception was thrown when setting IsolatedStorageContainment value [{0}]", isc.ToString()) Console.WriteLine(("Exception: " + ControlChars.Cr + ControlChars.Lf + e.ToString())) End If End Try If Not ExceptionCaught AndAlso exception_expected Then Console.WriteLine("An expected exception was not thrown when setting IsolatedStorageContainment value [{0}]", isc.ToString()) End If Return True End Function 'UsageAllowed ' ********************************************************************** ' DoDemand() ' This method demands an IsolatedStorageFilePermission. Private Function DoDemand() As Integer Dim ReturnValue As Integer = 0 Dim isfp0 As New IsolatedStorageFilePermission(PermissionState.Unrestricted) Try isfp0.Demand() Catch e As SecurityException ReturnValue = 1 Catch e As Exception Console.WriteLine(("An unexpected exception was thrown in DoDemand" + ControlChars.Cr + ControlChars.Lf + e.ToString())) ReturnValue = -1 End Try Return ReturnValue End Function 'DoDemand ' ********************************************************************** ' DemandUI() ' This method demands a UIPermission ' Returns: ' 0 if the demand was successful. ' 1 if a SecurityException was thrown. ' -1 if an unexpected exception was thrown. ' Private Function DemandUI() As Integer Dim ReturnValue As Integer = 0 Dim MyPermission As New UIPermission(PermissionState.Unrestricted) Try MyPermission.Demand() Catch e As SecurityException ReturnValue = 1 Catch e As Exception Console.WriteLine(("An unexpected exception was thrown in DemandUI" + ControlChars.Cr + ControlChars.Lf + e.ToString())) End Try Return ReturnValue End Function 'DemandUI Public Overloads Shared Function Main(ByVal args() As [String]) As Integer Dim MyDemo As New Demo MyDemo.Run() Return 0 End Function 'Main End Class 'Demo
import System .* ;
import System.Security .* ;
import System.IO .* ;
import System.IO.IsolatedStorage .* ;
import System.Security.Permissions .* ;
import System.Diagnostics .* ;
public class Demo
{
// Main method.
public void Run()
{
try {
Copy_EqualsDemo();
To_FromXmlDemo();
GetTypeDemo();
IntersectDemo();
UnionDemo();
ToStringDemo();
Demand_DenyDemo();
PermitOnlyDemo();
UserQuota_UsageDemo();
IsSubsetOfDemo();
IsUnrestrictedDemo();
}
catch (System.Exception e) {
Console.WriteLine(("\r\n\nThe demo failed due to an "
+ "unexpected exception\r\n" + e.ToString()));
}
} //Run
// IsUnrestrictedDemo demonstrates the
// IsolatedStorageFilePermission.IsUnrestricted method.
// IsUnrestrictedDemo displays a comment indicating whether
// the current permission is unrestricted.
private void IsUnrestrictedDemo()
{
Console.WriteLine("IsUnrestricted demo.");
try {
IsolatedStorageFilePermission isfp =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
isfp.Demand(); // The permission should be unrestricted.
Console.WriteLine("Created and demanded the "
+ "IsolatedStorageFilePermission(PermissionState."
+ "Unrestricted)permission.");
if (true != isfp.IsUnrestricted()) {
Console.WriteLine("IsUnrestricted demo failed. "
+ "The IsUnrestricted property value should be 'true'");
}
isfp = new IsolatedStorageFilePermission(PermissionState.None);
isfp.Demand(); // The permission should not be unrestricted.
Console.WriteLine("Created and demanded the "
+ "IsolatedStorageFilePermission(PermissionState.None)"
+ "permission.");
if (false != isfp.IsUnrestricted()) {
Console.WriteLine("IsUnrestricted demo failed. The "
+ "IsUnrestricted property value should be 'false'");
}
}
catch (System.Exception e) {
Console.WriteLine(("Unexpected exception: " + e.get_Message()));
}
} //IsUnrestrictedDemo
// Copy_EqualsDemo demonstrates the Copy and Equals methods.
// Copy creates and returns an identical copy of the current permission.
// Equals compares two permissions and determines whether they are equal.
private void Copy_EqualsDemo()
{
Console.WriteLine("\nCopy_Equals demo.");
Console.WriteLine("Creating the first "
+ "IsolatedStorageFilePermission(PermissionState."
+ "Unrestricted) permission.");
IsolatedStorageFilePermission first =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
Console.WriteLine(("Hashcode for the first permission : "
+ System.Convert.ToString(first.GetHashCode())));
Console.WriteLine("Copying the first permission.");
IsolatedStorageFilePermission copyOfFirst =
((IsolatedStorageFilePermission)(first.Copy()));
Console.WriteLine(("Hashcode for copy of the first permission: "
+ System.Convert.ToString(copyOfFirst.GetHashCode())));
if (false == copyOfFirst.Equals(first)) {
// This should be false, because the object references are
// different.
Console.WriteLine(("The copy and the first permission "
+ "should not be equal because they have "
+ "\n\tdifferent object references."));
}
else {
Console.WriteLine(("Error: the copy and the first "
+ "permission should not be equal because they have "
+ "\n\tdifferent object references."));
}
Console.WriteLine("Does a comparison of copy of first "
+ "permission to itself test equal??: "
+ ((copyOfFirst.Equals(copyOfFirst)) ? "true" : "false"));
if (false == copyOfFirst.Equals(copyOfFirst)) {
Console.WriteLine("Copy_Equals demo failed because Equals "
+ "returns false on two object.Equals(itself).");
}
Console.WriteLine(("Does a comparison of first permission to "
+ "itself test equal?: "
+ ((first.Equals(first)) ? "true" : "false")));
if (false == first.Equals(first)) {
Console.WriteLine("Copy_Equals demo failed, because Equals "
+ "returns false on two object.Equals(itself).");
}
Console.WriteLine("Creating a second permission with "
+ "PermissionState.None.");
IsolatedStorageFilePermission second =
new IsolatedStorageFilePermission(PermissionState.None);
Console.WriteLine(("Does the first permission equal the "
+ "second permission?: "
+ ((first.Equals(second)) ? "true" : "false")));
if (true == first.Equals(second)) {
Console.WriteLine("Copy_Equals demo failed because Equals "
+ "returns false on two object.Equals(itself).");
}
} //Copy_EqualsDemo
// To_FromXmlDemo demonstrates ToXml and FromXml.
// ToXml creates an XML encoding of the permission and its current state.
// FromXml reconstructs a permission with a specified state from
// an XML encoding.
private void To_FromXmlDemo()
{
Console.WriteLine("\nTo_FromXML demo.");
IsolatedStorageFilePermission firstPermission =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
Console.WriteLine(("First permission: " + firstPermission.ToString()));
SecurityElement se = firstPermission.ToXml();
IsolatedStorageFilePermission secondPermission =
new IsolatedStorageFilePermission(PermissionState.None);
Console.WriteLine(("Second permission: "
+ secondPermission.ToString()));
secondPermission.FromXml(se);
IsolatedStorageFilePermission thirdPermission =
((IsolatedStorageFilePermission)
(secondPermission.Intersect(firstPermission)));
Console.WriteLine(("Intersection of first permission and "
+ "second permission: " + thirdPermission.ToString()));
try {
if (false == thirdPermission.IsUnrestricted()) {
Console.WriteLine("To_FromXml demo failed: The ToXml, "
+ "FromXml roundtrip did not succeed.");
}
}
catch (System.Exception e) {
Console.WriteLine("To_FromXml demo failed: An exception "
+ "was thrown when checking the intersection");
Console.WriteLine("of the permissions after the XML roundtrip.");
Console.WriteLine(e.ToString());
Console.WriteLine(e.ToString());
}
} //To_FromXmlDemo
// GetType demonstrates the GetType method.
// This method returns the type of the current instance.
private void GetTypeDemo()
{
Console.WriteLine("\nGetType demo.");
IsolatedStorageFilePermission isfp =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
IsolatedStorageFilePermission isfp1 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
if (0 != isfp.GetType().toString().CompareTo(
"System.Security.Permissions.IsolatedStorageFilePermission")) {
Console.WriteLine(("GetType returned the wrong value: "
+ isfp.GetType().toString()));
}
else {
Console.WriteLine(("GetType returned: "
+ isfp.GetType().toString()));
}
} //GetTypeDemo
// IntersectDemo demonstrates the Intersect method.
// CIntersect creates and returns a permission that is the intersection
// of the current permission and the specified permission.
// Note The intersection of two PermissionState.None permissions *IS* null.
private void IntersectDemo()
{
Console.WriteLine("\nIntersect demo.");
IsolatedStorageFilePermission isfp0 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
IsolatedStorageFilePermission isfp1 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
IsolatedStorageFilePermission isfp2 =
new IsolatedStorageFilePermission(PermissionState.None);
IsolatedStorageFilePermission isfp3 =
new IsolatedStorageFilePermission(PermissionState.None);
IsolatedStorageFilePermission t =
((IsolatedStorageFilePermission)(isfp0.Intersect(isfp1)));
if (true == t.IsUnrestricted()) {
Console.WriteLine("The intersection of two "
+ "PermissionState.Unrestricted permissions is unrestricted.");
}
else {
Console.WriteLine(("Intersect demo failed because the "
+ "intersection of two unrestricted permissions "
+ "\n\tshould be unrestricted."));
}
t = ((IsolatedStorageFilePermission)(isfp0.Intersect(isfp2)));
if (false == t.IsUnrestricted()) {
Console.WriteLine(("The intersection of a "
+ "PermissionState.Unrestricted and "
+ "\n\tPermissionState.None permission is not unrestricted."));
}
else {
Console.WriteLine(("Intersect demo failed because the "
+ "intersection of a unrestricted and "
+ "\n\tnone permission should be none."));
}
// The permission set that comes back from this intersection is null.
t = ((IsolatedStorageFilePermission)(isfp2.Intersect(isfp3)));
if (null == t) {
Console.WriteLine("The intersection of two "
+ "PermissionState.None permissions is null.");
}
else {
Console.WriteLine(("Intersect failed because the "
+ "intersection of two PermissionState.None permissions "
+ "\n\tshould be null."));
}
} //IntersectDemo
// UnionDemo demonstrates the Union method.
// Union creates a permission that is the union of the current
// permission and the specified permission.
// Note: The union of two PermissionState.None permissions is *NOT* null.
private void UnionDemo()
{
Console.WriteLine("\nUnion demo.");
IsolatedStorageFilePermission isfp0 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
IsolatedStorageFilePermission isfp1 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
IsolatedStorageFilePermission isfp2 =
new IsolatedStorageFilePermission(PermissionState.None);
IsolatedStorageFilePermission isfp3 =
new IsolatedStorageFilePermission(PermissionState.None);
IsolatedStorageFilePermission t =
((IsolatedStorageFilePermission)(isfp0.Union(isfp1)));
if (true == t.IsUnrestricted()) {
Console.WriteLine("The union of two "
+ "PermissionState.Unrestricted permissions is unrestricted.");
}
else {
Console.WriteLine(("Union demo failed because the union "
+ "of two PermissionState.Unrestricted permissions "
+ "\n\tshould be unrestricted"));
}
t = ((IsolatedStorageFilePermission)(isfp0.Union(isfp2)));
if (true == t.IsUnrestricted()) {
Console.WriteLine(("The union of a PermissionState.Unrestricted "
+ "and a PermissionState.None "
+ "\n\tpermission is unrestricted."));
}
else {
Console.WriteLine(("Union demo failed because the union of a "
+ "PermissionState.Unrestricted and a "
+ "\n\tPermissionState.None permission should be "
+ "unrestricted."));
}
t = ((IsolatedStorageFilePermission)(isfp2.Union(isfp3)));
if (null != t) {
Console.WriteLine("The union of two PermissionState.None "
+ "permissions is none.");
}
else {
Console.WriteLine("Union failed because the union of two "
+ "PermissionState.None permissions should not be null.");
Console.WriteLine(t.ToString());
}
} //UnionDemo
// ToStringDemo demonstrates the ToString method.
// ToString creates and returns a string representation of the current
// permission object.
private void ToStringDemo()
{
Console.WriteLine("\nToString demo.");
IsolatedStorageFilePermission isfp0 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
String permString = isfp0.ToString();
String permStringParts[] = {"class=", "mscorlib", "Version=",
"Culture=", "PublicKeyToken=", "version=", "Unrestricted="};
for (int iCtr = 0; iCtr < permStringParts.length; iCtr++) {
String part = permStringParts[iCtr];
if (permString.IndexOf(part) >= 0) {
Console.WriteLine((part + " found in the string."));
}
else {
Console.WriteLine("ToString demo failed because [{0}] "
+ "was not found.", part);
}
}
} //ToStringDemo
// Demand_Deny demonstrates Demand and Deny.
// Demand forces a SecurityException at run time if all callers higher
// in the call stack have not been granted the permission specified
// by the current instance.
// Deny prevents callers higher in the call stack from using the code
// that calls this method to
// access the resource specified by the current instance.
private void Demand_DenyDemo()
{
Console.WriteLine("\nDemand_Deny demo.");
Console.WriteLine("Denying a permission with "
+ "PermissionState.Unrestricted.");
IsolatedStorageFilePermission isfp0 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
isfp0.Deny();
try {
Console.WriteLine("Denying permission a second time.");
isfp0.Deny();
}
catch (SecurityException exp) {
Console.WriteLine("SecurityException was thrown as expected.");
}
catch (System.Exception e) {
Console.WriteLine(("Demand_Deny demo failed because an "
+ "unexpected exception was thrown"
+ "\n\twhen making a second call to Deny()\r\n"
+ e.ToString()));
}
Console.WriteLine("Reverting the deny.");
IsolatedStorageFilePermission.RevertDeny();
if (0 != DoDemand()) {
Console.WriteLine("Demand_Deny demo failed because an "
+ "unexpected exception was thrown during a demand.");
}
isfp0.Deny();
if (1 != DoDemand()) {
Console.WriteLine("Demand_Deny demo failed because the "
+ "expected SecurityException was not thrown during a demand.");
}
IsolatedStorageFilePermission.RevertDeny();
if (0 != DoDemand()) {
Console.WriteLine("Demand_Deny demo failed because an "
+ "unexpected exception was thrown during a demand.");
}
} //Demand_DenyDemo
// PermitOnly demonstrates the PermitOnly method.
// PermitOnly prevents callers higher in the call stack from using the
// code that calls this method to access all resources except for the
// resource specified by the current instance.
private void PermitOnlyDemo()
{
Console.WriteLine("\nPermitOnly demo.");
IsolatedStorageFilePermission isfp0 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
isfp0.Demand();
isfp0.PermitOnly();
try {
isfp0.PermitOnly();
}
catch (SecurityException exp) {
Console.WriteLine("The second call to PermitOnly caused an "
+ "exception as expected.");
}
catch (System.Exception e) {
Console.WriteLine(("PermitOnly demo failed because an "
+ "unexpected exception was thrown"
+ "\n\twhen making a second call to PermitOnly()\r\n"
+ e.ToString()));
}
IsolatedStorageFilePermission.RevertPermitOnly();
if (0 != DemandUI()) {
Console.WriteLine("PermitOnly demo failed because an "
+ "exception was thrown during a demand for UI permissions.");
Console.WriteLine("We weren't expecting this.");
}
isfp0.PermitOnly();
if (1 != DemandUI()) {
Console.WriteLine(("PermitOnly demo failed because a "
+ "SecurityException was not thrown, "
+ "\n\tduring a demand for UI permissions. "
+ "A SecurityException was expected."));
}
IsolatedStorageFilePermission.RevertPermitOnly();
if (0 != DoDemand()) {
Console.WriteLine("PermitOnly failed because an exception "
+ "was thrown during a demand for UI permissions.");
Console.WriteLine("We weren't expecting this.");
}
} //PermitOnlyDemo
// UserQuota_UsageDemo demonstrates UserQuota and UsageAllowed properties.
// UserQuota gets or sets the quota on the overall size of each user's
// total store. This property is inherited from
// IsolatedStoragePermission.UserQuota. UsageAllowed gets or sets the
// type of isolated storage containment allowed. This property is inherited
// from IsolatedStoragePermission.UsageAllowed. Note You can set
// UsageAllowed to None, but you cannot set UserQuota to 0. Also note that
// trying to set UsageAllowed or UserQuota to values that are currently set
// will throw an exception.
/** @attribute.method IsolatedStorageFilePermissionAttribute(
SecurityAction.Deny,
UsageAllowed = IsolatedStorageContainment.DomainIsolationByRoamingUser,
UserQuota = 100)
*/
private void UserQuota_UsageDemo()
{
Console.WriteLine("\nUserQuota_Usage demo.");
boolean returnValue = false;
IsolatedStorageFilePermission isfp0 =
new IsolatedStorageFilePermission(PermissionState.None);
Console.WriteLine(
"Checking UsageAllowed for IsolatedStorageContainment.None");
returnValue = UsageAllowed(isfp0, IsolatedStorageContainment.None,
false);
if (!(returnValue)) {
Console.WriteLine("IsolatedStorageContainment.None demo failed");
}
Console.WriteLine("Checking UsageAllowed for "
+ "IsolatedStorageContainment.DomainIsolationByRoamingUser.");
returnValue = UsageAllowed(isfp0,
IsolatedStorageContainment.DomainIsolationByRoamingUser, true);
if (!(returnValue)) {
Console.WriteLine("IsolatedStorageContainment."
+ "DomainIsolationByRoamingUser failed");
}
Console.WriteLine("Checking UsageAllowed for "
+ "IsolatedStorageContainment.AssemblyIsolationByUser.");
returnValue = UsageAllowed(isfp0,
IsolatedStorageContainment.AssemblyIsolationByUser, true);
if (!(returnValue)) {
Console.WriteLine(
"IsolatedStorageContainment.AssemblyIsolationByUse failed");
}
Console.WriteLine("Requesting UserQuota of 0.");
returnValue = UserQuota(isfp0, 0, true);
if (!(returnValue)) {
Console.WriteLine("UserQuota 0 failed");
}
Console.WriteLine("Requesting UserQuota of 100.");
returnValue = UserQuota(isfp0, 100, true);
if (!(returnValue)) {
Console.WriteLine("UserQuota 100 failed");
}
Console.WriteLine("Requesting UserQuota of -2147483648.");
returnValue = UserQuota(isfp0, -2147483648, true);
if (!(returnValue)) {
Console.WriteLine("UserQuota -214748364 failed");
}
} //UserQuota_UsageDemo
// IsSubsetOfDemo demonstrates the IsSubsetOf method.
// IsSubsetOf determines whether the current permission is a subset
// of the specified permission.
private void IsSubsetOfDemo()
{
Console.WriteLine("\nIsSubsetOf demo.");
IsolatedStorageFilePermission isfp0 =
new IsolatedStorageFilePermission(PermissionState.None);
IsolatedStorageFilePermission isfp1 =
new IsolatedStorageFilePermission(PermissionState.None);
IsolatedStorageFilePermission isfp2 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
IsolatedStorageFilePermission isfp3 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
if (isfp0.IsSubsetOf(isfp1)) {
Console.WriteLine("PermissionState.None is a subset of "
+ "PermissionState.None.");
}
else {
Console.WriteLine("IsSubsetOfDemo failed: PermissionState.None "
+ "should be a subset of PermissionState.None");
}
if (isfp0.IsSubsetOf(isfp2)) {
Console.WriteLine("PermissionState.None is a subset of "
+ "PermissionState.Unrestricted.");
}
else {
Console.WriteLine("IsSubsetOfDemo failed: PermissionState.None "
+ "should be a subset of PermissionState.Unrestricted");
}
if (!(isfp2.IsSubsetOf(isfp0))) {
Console.WriteLine("PermissionState.Unrestricted is not "
+ "a subset of PermissionState.None.");
}
else {
Console.WriteLine(("IsSubsetOfDemo failed: PermissionState."
+ "Unrestricted should not be a subset "
+ "\n\tof PermissionState.None"));
}
if (isfp2.IsSubsetOf(isfp3)) {
Console.WriteLine("PermissionState.Unrestricted is a "
+ "subset of PermissionState.Unrestricted.");
}
else {
Console.WriteLine(("IsSubsetOfDemo failed: "
+ "Permissionstate.Unrestricted should be a subset of "
+ "\n\tPermissionState.Unrestricted"));
}
} //IsSubsetOfDemo
// **********************************************************************
// The following methods are simple helper functions.
// **********************************************************************
// **********************************************************************
// UserQuota
// Sets UserQuota to the value that was passed in.
//
private boolean UserQuota(IsolatedStorageFilePermission isfp,
int userQuota, boolean exceptionExpected)
{
boolean exceptionCaught = false;
isfp.set_UserQuota(userQuota);
try {
isfp.Demand();
}
catch (System.Exception e) {
exceptionCaught = true;
if (!(exceptionExpected)) {
Console.WriteLine("An unexpected exception was thrown "
+ "when setting UserQuota value [{0}]",
System.Convert.ToString(userQuota));
Console.WriteLine(("Exception: \r\n" + e.ToString()));
}
}
if ((!(exceptionCaught)) && exceptionExpected) {
Console.WriteLine("An expected exception not thrown "
+ "when setting UserQuota value [{0}]",
System.Convert.ToString(userQuota));
}
return true;
} //UserQuota
// **********************************************************************
// UsageAllowed
// This method sets UsageAllowed to the value that was passed in.
//
private boolean UsageAllowed(IsolatedStorageFilePermission isfp,
IsolatedStorageContainment isc, boolean exceptionExpected)
{
boolean exceptionCaught = false;
isfp.set_UsageAllowed(isc);
try {
isfp.Demand();
}
catch (System.Exception e) {
exceptionCaught = true;
if (!(exceptionExpected)) {
Console.WriteLine("An unexpected exception was thrown "
+ "when setting IsolatedStorageContainment value [{0}]",
isc.ToString());
Console.WriteLine(("Exception: \r\n" + e.ToString()));
}
}
if (!(exceptionCaught) && exceptionExpected) {
Console.WriteLine("An expected exception was not thrown "
+ "when setting IsolatedStorageContainment value [{0}]",
isc.ToString());
}
return true;
} //UsageAllowed
// **********************************************************************
// DoDemand()
// This method demands an IsolatedStorageFilePermission.
private int DoDemand()
{
int returnValue = 0;
IsolatedStorageFilePermission isfp0 =
new IsolatedStorageFilePermission(PermissionState.Unrestricted);
try {
isfp0.Demand();
}
catch (SecurityException exp) {
returnValue = 1;
}
catch (System.Exception e) {
Console.WriteLine(("An unexpected exception was "
+ "thrown in DoDemand\r\n" + e.ToString()));
returnValue = -1;
}
return returnValue;
} //DoDemand
// **********************************************************************
// DemandUI()
// This method demands a UIPermission
// Returns:
// 0 if the demand was successful.
// 1 if a SecurityException was thrown.
// -1 if an unexpected exception was thrown.
//
private int DemandUI()
{
int returnValue = 0;
UIPermission MyPermission =
new UIPermission(PermissionState.Unrestricted);
try {
MyPermission.Demand();
}
catch (SecurityException exp) {
returnValue = 1;
}
catch (System.Exception e) {
Console.WriteLine(("An unexpected exception was thrown "
+ "in DemandUI\r\n" + e.ToString()));
}
return returnValue;
} //DemandUI
public static void main(String[] args)
{
Demo myDemo = new Demo();
myDemo.Run();
return;
} //main
} //Demo
System.Security.CodeAccessPermission
System.Security.Permissions.IsolatedStoragePermission
System.Security.Permissions.IsolatedStorageFilePermission
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
Note