SocketPermission.Union(IPermission) Method

Definition

Namespace:

System.Net

Assembly:

System.Security.Permissions.dll

Source:

SocketPermission.cs

Returns the logical union between two SocketPermission instances.

C#

public override System.Security.IPermission Union(System.Security.IPermission target);

Parameters

target

IPermission

The SocketPermission instance to combine with the current instance.

Returns

IPermission

The SocketPermission instance that represents the union of two SocketPermission instances. If target parameter is null, it returns a copy of the current instance.

Exceptions

ArgumentException

target is not a SocketPermission.

Examples

The following example uses the Union method to return the logical union of two existing SocketPermission instances.

C#

// Creates a SocketPermission restricting access to and from all URIs.
SocketPermission mySocketPermission1 = new SocketPermission(PermissionState.None);

// The socket to which this permission will apply will allow connections from www.contoso.com.
mySocketPermission1.AddPermission(NetworkAccess.Accept, TransportType.Tcp, "www.contoso.com", 11000);

// Creates a SocketPermission which will allow the target Socket to connect with www.southridgevideo.com.
SocketPermission mySocketPermission2 =
                           new SocketPermission(NetworkAccess.Connect, TransportType.Tcp, "www.southridgevideo.com", 11002);

// Creates a SocketPermission from the union of two SocketPermissions.
SocketPermission mySocketPermissionUnion =
                           (SocketPermission)mySocketPermission1.Union(mySocketPermission2);

// Checks to see if the union was successfully created by using the IsSubsetOf method.
if (mySocketPermission1.IsSubsetOf(mySocketPermissionUnion) &&
      mySocketPermission2.IsSubsetOf(mySocketPermissionUnion)){
     Console.WriteLine("This union contains permissions from both mySocketPermission1 and mySocketPermission2");

     // Prints the allowable accept URIs to the console.
     Console.WriteLine("This union accepts connections on :");

     IEnumerator myEnumerator = mySocketPermissionUnion.AcceptList;
  while (myEnumerator.MoveNext()) {
          Console.WriteLine(((EndpointPermission)myEnumerator.Current).ToString());
       }

        // Prints the allowable connect URIs to the console.
     Console.WriteLine("This union permits connections to :");

     myEnumerator = mySocketPermissionUnion.ConnectList;
  while (myEnumerator.MoveNext()) {
          Console.WriteLine(((EndpointPermission)myEnumerator.Current).ToString());
       }
      }

Remarks

The result of a call to Union is a permission that represents all of the access to Socket connections represented by the current instance as well as the access represented by target. Any demand that passes either the current instance or target passes their union. This method overrides Union and is implemented to support the IPermission interface.

Applies to