Intersect Method
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SocketPermission.Intersect Method (IPermission)

 

Returns the logical intersection between two SocketPermission instances.

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

public override IPermission Intersect(
	IPermission target
)

Parameters

target
Type: System.Security.IPermission

The SocketPermission instance to intersect with the current instance.

Return Value

Type: System.Security.IPermission

The SocketPermission instance that represents the intersection of two SocketPermission instances. If the intersection is empty, the method returns null. If the target parameter is a null reference, the method returns null.

Exception Condition
ArgumentException

The target parameter is not a SocketPermission.

SecurityException

DnsPermission is not granted to the method caller.

The intersection of two permissions is a permission that helps to protect the resources and operations protected by both permissions. Specifically, it represents the minimum permission such that any demand that passes both permissions also passes their intersection. This method overrides Intersect and is implemented to support the IPermission interface.

The following example uses the Intersect method to obtain a logical intersection between two SocketPermission instances.

SocketPermission socketPermission1 = new SocketPermission(PermissionState.Unrestricted);

// Create a 'SocketPermission' object for two ip addresses.
SocketPermission socketPermission2 = new SocketPermission(PermissionState.None);
SecurityElement securityElement1 = socketPermission2.ToXml();
// 'SocketPermission' object for 'Connect' permission
SecurityElement securityElement2 = new SecurityElement("ConnectAccess");
// Format to specify ip address are <ip-address>#<port>#<transport-type>
// First 'SocketPermission' ip-address is '192.168.144.238' for 'All' transport types and 
    // for 'All'ports for the ip-address.
SecurityElement securityElement3 = new SecurityElement("URI", "192.168.144.238#-1#3");
// Second 'SocketPermission' ip-address is '192.168.144.240' for 'All' transport types and 
    // for 'All' ports for the ip-address.
SecurityElement securityElement4 = new SecurityElement("URI", "192.168.144.240#-1#3");
securityElement2.AddChild(securityElement3);
securityElement2.AddChild(securityElement4);
securityElement1.AddChild(securityElement2);

  // Obtain a 'SocketPermission' object using 'FromXml' method.
socketPermission2.FromXml(securityElement1);

Console.WriteLine("\nDisplays the result of FromXml method : \n");
Console.WriteLine(socketPermission2.ToString());

// Create another 'SocketPermission' object with two ip addresses.
// First 'SocketPermission' ip-address is '192.168.144.238' for 'All' transport types and for 'All' ports for the ip-address.
SocketPermission socketPermission3 = 
				new SocketPermission(NetworkAccess.Connect,
									 TransportType.All,
									 "192.168.144.238",
									 SocketPermission.AllPorts);

  // Second 'SocketPermission' ip-address is '192.168.144.239' for 'All' transport types and for 'All' ports for the ip-address.
socketPermission3.AddPermission(NetworkAccess.Connect,
							   TransportType.All,
							   "192.168.144.239",
							   SocketPermission.AllPorts);

Console.WriteLine("Displays the result of AddPermission method : \n");
Console.WriteLine(socketPermission3.ToString());

  // Find the intersection between two 'SocketPermission' objects.
socketPermission1 = (SocketPermission)socketPermission2.Intersect(socketPermission3);

Console.WriteLine("Displays the result of Intersect method :\n ");
Console.WriteLine(socketPermission1.ToString());

// Demand that the calling method have the requsite socket permission.
socketPermission1.Demand();

.NET Framework
Available since 1.1
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