IPermission.Intersect(IPermission) Method

Definition

Namespace:

System.Security

Assemblies:

netstandard.dll, System.Runtime.dll

Creates and returns a permission that is the intersection of the current permission and the specified permission.

C#

public System.Security.IPermission? Intersect(System.Security.IPermission? target);

Parameters

target

IPermission

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

Returns

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.

Exceptions

ArgumentException

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

Examples

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

C#

// 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);
}

Remarks

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.

Applies to