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SocketPermission.Intersect Method

Returns the logical intersection between two SocketPermission instances.

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

'Declaration
Public Overrides Function Intersect ( _
	target As IPermission _
) As IPermission
'Usage
Dim instance As SocketPermission
Dim target As IPermission
Dim returnValue As IPermission

returnValue = instance.Intersect(target)
public IPermission Intersect (
	IPermission target
)
public override function Intersect (
	target : IPermission
) : IPermission
Not applicable.

Parameters

target

The SocketPermission instance to intersect with the current instance.

Return Value

The SocketPermission instance that represents the intersection of two SocketPermission instances. If the intersection is empty, the method returns a null reference (Nothing in Visual Basic). If the target parameter is a null reference, the method returns a null reference (Nothing in Visual Basic).

Exception typeCondition

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.


Dim socketPermission1 As New SocketPermission(PermissionState.Unrestricted)

'Create a 'SocketPermission' object for two ip addresses.
Dim socketPermission2 As New SocketPermission(PermissionState.None)
Dim securityElement1 As SecurityElement = socketPermission2.ToXml()
''SocketPermission' object for 'Connect' permission
Dim securityElement2 As 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.
Dim securityElement3 As 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.
Dim securityElement4 As 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(ControlChars.Cr + "Displays the result of FromXml method : " + ControlChars.Cr)
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.
Dim socketPermission3 As 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 : " + ControlChars.Cr)
Console.WriteLine(socketPermission3.ToString())

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

Console.WriteLine("Displays the result of Intersect method :" + ControlChars.Cr + " ")
Console.WriteLine(socketPermission1.ToString())
'Demand that the calling method have the requsite socket permission.
socketPermission1.Demand()

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();

Windows 98, Windows Server 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 Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0
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