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CodeAccessPermission.Union Method

When overridden in a derived class, creates a permission that is the union of the current permission and the specified permission.

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

public virtual IPermission Union(
	IPermission other


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.




The other parameter is not null. This method is only supported at this level when passed null.

The result of a call to Union is a permission that represents all the operations represented by both the current permission and the specified permission. Any demand that passes either permission passes their union.

Notes to Inheritors

You must override this method in a derived class. You should return a copy of the permission if the value of the other parameter is null.

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

        public override IPermission Union(IPermission target)
            Console.WriteLine ("************* Entering Union *********************");
            if (target == null)
                return this;
            Console.WriteLine ("This is = " + (( NameIdPermission)this).Name);
            Console.WriteLine ("Target is " + (( NameIdPermission)target).m_Name);
            if (!VerifyType(target))
                throw new ArgumentException (String.Format ("Argument_WrongType", this.GetType ().FullName));

             NameIdPermission operand = ( NameIdPermission)target;

            if (operand.IsSubsetOf (this)) return this.Copy ();
            else if (this.IsSubsetOf (operand)) return operand.Copy ();
                return null;

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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