Export (0) Print
Expand All

CodeAccessPermission.Union Method

When overridden in a derived class, creates a permission that is the union of the current permission and the specified permission.

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

'Declaration
Public Overridable Function Union ( _
	other As IPermission _
) As IPermission

Parameters

other
Type: System.Security.IPermission

A permission to combine with the current permission. It must be of the same type as the current permission.

Return Value

Type: System.Security.IPermission
A new permission that represents the union of the current permission and the specified permission.

Implements

IPermission.Union(IPermission)

ExceptionCondition
NotSupportedException

The other parameter is not Nothing. This method is only supported at this level when passed Nothing.

The result of a call to Union is a permission that represents all the operations represented by both the current permission and the specified permission. Any demand that passes either permission passes their union.

Notes to Inheritors

You must override this method in a derived class. You should return a copy of the permission if the value of the other parameter is Nothing.

The following code example shows an override of the Union method. This code example is part of a larger example provided for the CodeAccessPermission class.

Public Overrides Function Union(ByVal target As IPermission) As IPermission
#If (Debug) Then

            Console.WriteLine("************* Entering Union *********************")
#End If 
            If target Is Nothing Then 
                Return Me 
            End If
#If (Debug) Then
            Console.WriteLine(("This is = " + CType(Me, NameIdPermission).Name))
            Console.WriteLine(("Target is " + CType(target, NameIdPermission).m_name))
#End If 
            If Not VerifyType(target) Then 
                Throw New ArgumentException(String.Format("Argument_WrongType", Me.GetType().FullName))
            End If 

            Dim operand As NameIdPermission = CType(target, NameIdPermission)

            If operand.IsSubsetOf(Me) Then 
                Return Me.Copy()
            ElseIf Me.IsSubsetOf(operand) Then 
                Return operand.Copy()
            Else 
                Return Nothing 
            End If 
        End Function 'Union

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Show:
© 2014 Microsoft