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DnsPermission.Union Method

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

Namespace: System.Net
Assembly: System (in system.dll)

public override IPermission Union (
	IPermission target
)
public IPermission Union (
	IPermission target
)
public override function Union (
	target : IPermission
) : IPermission

Parameters

target

The DnsPermission instance to combine with the current instance.

Return Value

A DnsPermission instance that represents the union of the current DnsPermission instance with the specified DnsPermission instance. If target is a null reference (Nothing in Visual Basic), this method returns a copy of the current instance. If the current instance or target is unrestricted, this method returns a DnsPermission instance that is unrestricted; otherwise, it returns a DnsPermission instance that is restricted.
Exception typeCondition

ArgumentException

target is neither a DnsPermission nor a null reference (Nothing in Visual Basic).

The Union method returns a DnsPermission instance that allows the access defined by either the current DnsPermission instance or the specified DnsPermission instance. Any demand that passes either permission passes their union.

The following example creates a permission instance that is the union of the current permission instance and the specified permission instance.

private void MyUnion()
{
   // Create a DnsPermission instance that is the union of the current DnsPermission
   // instance and the specified DnsPermission instance.     
   DnsPermission permission = (DnsPermission)dnsPermission1.Union(dnsPermission2);
   // Print the attributes and the values of the union instance of DnsPermission.
   PrintKeysAndValues(permission.ToXml().Attributes);
}
public void useDns() {
   // Create a DnsPermission instance.
   dnsPermission1 = new DnsPermission(PermissionState.Unrestricted);
   dnsPermission2 = new DnsPermission(PermissionState.None);
   // Check for permission.
   dnsPermission1.Demand();
   dnsPermission2.Demand();
   Console.WriteLine("Attributes and Values of first DnsPermission instance :");
   PrintKeysAndValues(dnsPermission1.ToXml().Attributes);
   Console.WriteLine("Attributes and Values of second DnsPermission instance :");
   PrintKeysAndValues(dnsPermission2.ToXml().Attributes);
   Console.WriteLine("Union of both instances : ");
   MyUnion();
   Console.WriteLine("Intersection of both instances : ");
   MyIntersection();
}

private void PrintKeysAndValues(Hashtable myList) {
   // Get the enumerator that can iterate through the hash tabble.
   IDictionaryEnumerator myEnumerator = myList.GetEnumerator();
   Console.WriteLine("\t-KEY-\t-VALUE-");
   while (myEnumerator.MoveNext())
      Console.WriteLine("\t{0}:\t{1}", myEnumerator.Key, myEnumerator.Value);
   Console.WriteLine();
}

private void MyUnion()
{
    // Create a DnsPermission instance that is the union of the 
    // current DnsPermission
    // instance and the specified DnsPermission instance.     
    DnsPermission permission = (DnsPermission)dnsPermission1.
        Union(dnsPermission2);

    // Print the attributes and the values of the union 
    // instance of DnsPermission.
    PrintKeysAndValues(permission.ToXml().get_Attributes());
} //MyUnion

public void UseDns()
{
    // Create a DnsPermission instance.
    dnsPermission1 = new DnsPermission(PermissionState.Unrestricted);
    dnsPermission2 = new DnsPermission(PermissionState.None);

    // Check for permission.
    dnsPermission1.Demand();
    dnsPermission2.Demand();
    Console.WriteLine("Attributes and Values of first DnsPermission "
        + "instance :");
    PrintKeysAndValues(dnsPermission1.ToXml().get_Attributes());
    Console.WriteLine("Attributes and Values of second DnsPermission "
        + "instance :");
    PrintKeysAndValues(dnsPermission2.ToXml().get_Attributes());
    Console.WriteLine("Union of both instances : ");
    MyUnion();
    Console.WriteLine("Intersection of both instances : ");
    MyIntersection();
} //UseDns

private void PrintKeysAndValues(Hashtable myList)
{
    // Get the enumerator that can iterate through the hash tabble.
    IDictionaryEnumerator myEnumerator = myList.GetEnumerator();
    Console.WriteLine("\t-KEY-\t-VALUE-");
    while (myEnumerator.MoveNext()) {
        Console.WriteLine("\t{0}:\t{1}", myEnumerator.get_Key(),
            myEnumerator.get_Value());
    }
    Console.WriteLine();
} //PrintKeysAndValues

Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0
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