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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


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.


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.

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 null.

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

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

  • X.Intersect(null) returns null.

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 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0