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UrlIdentityPermission.Union Method

Creates a permission that is the union of the current permission and the specified permission.

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

public override IPermission Union(
	IPermission target
)

Parameters

target
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
ArgumentException

The target parameter is not null and is not of the same type as the current permission.

-or-

The Url property is not a valid URL.

-or-

The two permissions are not equal and one is not a subset of the other.

The result of a call to the Union method is a permission that represents access to the URL as represented by the current permission, as well as access to the URL as represented by the specified permission.

The UrlIdentityPermission class supports set operations IsSubsetOf, Intersect, and Union) only when the current permission is equal to the specified permission, or when one of the permissions uses the wildcard operator ("*") and one is a subset of the other.

The following code example shows the behavior of the Union method. This example is part of a larger example provided for UrlIdentityPermission class.

NoteNote:

The code example is intended to show the behavior of the method, not to demonstrate its use. In general, the methods of permission classes are used by the security infrastructure; they are not typically used in applications.

// Union creates a new permission that is the union of the current permission 
// and the specified permission. 
private static void UnionDemo()
{
    UrlIdentityPermission permIdPerm1 = new UrlIdentityPermission("http://www.fourthcoffee.com/process/");
    UrlIdentityPermission permIdPerm2 = new UrlIdentityPermission("http://www.fourthcoffee.com/*");
    UrlIdentityPermission p3 = (UrlIdentityPermission)permIdPerm1.Union(permIdPerm2);
    try
    {
        if (p3 != null)
        {
            Console.WriteLine("The union of " + permIdPerm1.Url +
                " and \n\t" + permIdPerm2.Url + " is \n\t"
                + p3.Url + "\n");

        }
        else
        {
            Console.WriteLine("The union of " + permIdPerm1.Url +
                " and \n\t" + permIdPerm2.Url + " is null.\n");
        }
    }
    catch (SystemException e)
    {
        Console.WriteLine("The union of " + permIdPerm1.Url +
                " and \n\t" + permIdPerm2.Url + " failed.");

        Console.WriteLine(e.Message);
    }

}

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

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