UIPermission.IsSubsetOf(IPermission) Method

Definition

Namespace:

System.Security.Permissions

Assembly:

System.Security.Permissions.dll

Determines whether the current permission is a subset of the specified permission.

public:
 override bool IsSubsetOf(System::Security::IPermission ^ target);

public override bool IsSubsetOf (System.Security.IPermission target);

override this.IsSubsetOf : System.Security.IPermission -> bool

Public Overrides Function IsSubsetOf (target As IPermission) As Boolean

Parameters

target

IPermission

A permission to test for the subset relationship. This permission must be the same type as the current permission.

Returns

Boolean

true if the current permission is a subset of the specified permission; otherwise, false.

Exceptions

ArgumentException

The target parameter is not null and is not of the same type as the current permission.

Examples

The following code example shows the behavior of the IsSubsetOf method. This example is part of a larger example provided for the UIPermission class.

Note

The code example is intended to show the behavior of the method, not to demonstrate its use. In general, the methods of permission classes are used by the security infrastructure; they are not typically used in applications.

// IsSubsetOf determines whether the current permission is a subset of the specified permission.

void IsSubsetOfDemo()
{
    Console::WriteLine("\n**********************  IsSubsetOf() Demo **********************\n");
    UIPermission ^ uiPerm1 = gcnew UIPermission(UIPermissionWindow::SafeTopLevelWindows);
    UIPermission ^ uiPerm2 = gcnew UIPermission(UIPermissionWindow::SafeSubWindows);

    Console::WriteLine("   {0} is {1}a subset of {2} ", uiPerm1->Window,
                            uiPerm1->IsSubsetOf(uiPerm2)?"":"not ", uiPerm2->Window);

    Console::WriteLine("   {0} is {1}a subset of {2} ", uiPerm2->Window,
                            uiPerm2->IsSubsetOf(uiPerm1)?"":"not ", uiPerm1->Window);

    uiPerm1 = gcnew UIPermission(UIPermissionClipboard::AllClipboard);
    uiPerm2 = gcnew UIPermission(UIPermissionClipboard::OwnClipboard);

    Console::WriteLine("   {0} is {1}a subset of {2} ", uiPerm1->Clipboard,
                            uiPerm1->IsSubsetOf(uiPerm2)?"":"not ", uiPerm2->Clipboard);

    Console::WriteLine("   {0} is {1}a subset of {2} ", uiPerm2->Clipboard,
                            uiPerm2->IsSubsetOf(uiPerm1)?"":"not ", uiPerm1->Clipboard);
}

// IsSubsetOf determines whether the current permission is a subset of the specified permission.
private static void IsSubsetOfDemo()
{
    UIPermission uiPerm1 = new UIPermission(UIPermissionWindow.SafeTopLevelWindows);
    UIPermission uiPerm2 = new UIPermission(UIPermissionWindow.SafeSubWindows);
    CheckIsSubsetOfWindow(uiPerm1, uiPerm2);
    uiPerm1 = new UIPermission(UIPermissionClipboard.AllClipboard);
    uiPerm2 = new UIPermission(UIPermissionClipboard.OwnClipboard);
    CheckIsSubsetOfClipBoard(uiPerm1, uiPerm2);
}
private static void CheckIsSubsetOfWindow(UIPermission uiPerm1, UIPermission uiPerm2)
{
    if (uiPerm1.IsSubsetOf(uiPerm2))
    {
        Console.WriteLine(uiPerm1.Window.ToString() + " is a subset of " +
            uiPerm2.Window.ToString());
    }
    else
    {
        Console.WriteLine(uiPerm1.Window.ToString() + " is not a subset of " +
            uiPerm2.Window.ToString());
    }
    if (uiPerm2.IsSubsetOf(uiPerm1))
    {
        Console.WriteLine(uiPerm2.Window.ToString() + " is a subset of " +
            uiPerm1.Window.ToString());
    }
    else
    {
        Console.WriteLine(uiPerm2.Window.ToString() + " is not a subset of " +
            uiPerm1.Window.ToString());
    }
}
private static void CheckIsSubsetOfClipBoard(UIPermission uiPerm1, UIPermission uiPerm2)
{
    if (uiPerm1.IsSubsetOf(uiPerm2))
    {
        Console.WriteLine(uiPerm1.Clipboard.ToString() + " is a subset of " +
            uiPerm2.Clipboard.ToString());
    }
    else
    {
        Console.WriteLine(uiPerm1.Clipboard.ToString() + " is not a subset of " +
            uiPerm2.Clipboard.ToString());
    }
    if (uiPerm2.IsSubsetOf(uiPerm1))
    {
        Console.WriteLine(uiPerm2.Clipboard.ToString() + " is a subset of " +
            uiPerm1.Clipboard.ToString());
    }
    else
    {
        Console.WriteLine(uiPerm2.Clipboard.ToString() + " is not a subset of " +
            uiPerm1.Clipboard.ToString());
    }
}

' IsSubsetOf determines whether the current permission is a subset of the specified permission.
Private Shared Sub IsSubsetOfDemo()
    Dim uiPerm1 As New UIPermission(UIPermissionWindow.SafeTopLevelWindows)
    Dim uiPerm2 As New UIPermission(UIPermissionWindow.SafeSubWindows)
    CheckIsSubsetOfWindow(uiPerm1, uiPerm2)
    uiPerm1 = New UIPermission(UIPermissionClipboard.AllClipboard)
    uiPerm2 = New UIPermission(UIPermissionClipboard.OwnClipboard)
    CheckIsSubsetOfClipBoard(uiPerm1, uiPerm2)

End Sub

Private Shared Sub CheckIsSubsetOfWindow(ByVal uiPerm1 As UIPermission, ByVal uiPerm2 As UIPermission)
    If uiPerm1.IsSubsetOf(uiPerm2) Then
        Console.WriteLine(uiPerm1.Window.ToString() + " is a subset of " + uiPerm2.Window.ToString())
    Else
        Console.WriteLine(uiPerm1.Window.ToString() + " is not a subset of " + uiPerm2.Window.ToString())
    End If

    If uiPerm2.IsSubsetOf(uiPerm1) Then
        Console.WriteLine(uiPerm2.Window.ToString() + " is a subset of " + uiPerm1.Window.ToString())
    Else
        Console.WriteLine(uiPerm2.Window.ToString() + " is not a subset of " + uiPerm1.Window.ToString())
    End If

End Sub

Private Shared Sub CheckIsSubsetOfClipBoard(ByVal uiPerm1 As UIPermission, ByVal uiPerm2 As UIPermission)
    If uiPerm1.IsSubsetOf(uiPerm2) Then
        Console.WriteLine(uiPerm1.Clipboard.ToString() + " is a subset of " + uiPerm2.Clipboard.ToString())
    Else
        Console.WriteLine(uiPerm1.Clipboard.ToString() + " is not a subset of " + uiPerm2.Clipboard.ToString())
    End If

    If uiPerm2.IsSubsetOf(uiPerm1) Then
        Console.WriteLine(uiPerm2.Clipboard.ToString() + " is a subset of " + uiPerm1.Clipboard.ToString())
    Else
        Console.WriteLine(uiPerm2.Clipboard.ToString() + " is not a subset of " + uiPerm1.Clipboard.ToString())
    End If

End Sub

Remarks

The current permission is a subset of the specified permission if all demands that succeed for the current permission also succeed for the specified permission. That is, the specified permission contains at least the permissions contained in the subset. For IsSubsetOf to return true, both the UIPermissionWindow and UIPermissionClipboard values of the current permission must be equal to or less permissive than the values of the specified permission.