Intersect Method

CodeAccessPermission.Intersect Method (IPermission)

 

When implemented by a derived class, creates and returns a permission that is the intersection of the current permission and the specified permission.

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

Public MustOverride Function Intersect (
	target As IPermission
) As IPermission

Parameters

target
Type: System.Security.IPermission

A permission to intersect 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 intersection of the current permission and the specified permission. This new permission is null if the intersection is empty.

Exception Condition
ArgumentException

The target parameter is not null and is not an instance of the same class as the current permission.

The intersection of two permissions is a permission that describes the set of operations they both describe in common. Only a demand that passes both original permissions will pass the intersection.

Notes to Inheritors:

You must override this method in a derived class.

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

        Public Overrides Function Intersect(ByVal target As IPermission) As IPermission
            Console.WriteLine("************* Entering Intersect *********************")
            If target Is Nothing Then
                Return Nothing
            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 is wrong type.", Me.GetType().FullName))
            End If

            Dim operand As NameIdPermission = CType(target, NameIdPermission)

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

.NET Framework
Available since 1.1
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