IPermission.Intersect Method

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)

IPermission Intersect (
	IPermission target
)
IPermission Intersect (
	IPermission target
)
function Intersect (
	target : IPermission
) : IPermission
Not applicable.

Parameters

target

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

Return Value

A new permission that represents the intersection of the current permission and the specified permission. This new permission is a null reference (Nothing in Visual Basic) if the intersection is empty.

Exception typeCondition

ArgumentException

The target parameter is not a null reference (Nothing in Visual Basic) 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.

The following statements are required to be true for all implementations of the Intersect method. X and Y represent IPermission object references that are not a null reference (Nothing in Visual Basic).

  • X.Intersect(X) returns a value equal to X.

  • X.Intersect(Y) returns the same value as Y.Intersect(X).

  • X.Intersect(a null reference (Nothing in Visual Basic)) returns a null reference (Nothing in Visual Basic).

The following code example demonstrates implementing the Intersect method. This code example is part of a larger example provided for the IPermission class.

// Return a new object that contains the intersection of 'this' and 'target'.
public override IPermission Intersect(IPermission target) 
{
    // If 'target' is null, return null.
    if (target == null) return null;

    // Both objects must be the same type.
    SoundPermission soundPerm = VerifyTypeMatch(target);

    // If 'this' and 'target' are unrestricted, return a new unrestricted permission.
    if (m_specifiedAsUnrestricted && soundPerm.m_specifiedAsUnrestricted)
        return Clone(true, SoundPermissionState.PlayAnySound);

    // Calculate the intersected permissions. If there are none, return null.
    SoundPermissionState val = (SoundPermissionState)
        Math.Min((Int32) m_flags, (Int32) soundPerm.m_flags);
    if (val == 0) return null;

    // Return a new object with the intersected permission value.
    return Clone(false, val);
}

Windows 98, Windows Server 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 Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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