C# SocketPermission类代码示例

// 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());
            }      
           }


     // Creates a SocketPermission from the intersect of two SocketPermissions.
     SocketPermission mySocketPermissionIntersect = 
                               (SocketPermission)mySocketPermission1.Intersect(mySocketPermissionUnion);

     // mySocketPermissionIntersect should now contain the permissions of mySocketPermission1.
     if (mySocketPermission1.IsSubsetOf(mySocketPermissionIntersect)){
          Console.WriteLine("This is expected");
     }
    // mySocketPermissionIntersect should not contain the permissios of mySocketPermission2.
     if (mySocketPermission2.IsSubsetOf(mySocketPermissionIntersect)){
          Console.WriteLine("This should not print");
     }


// Creates a copy of the intersect SocketPermission.
     SocketPermission mySocketPermissionIntersectCopy = 
                               (SocketPermission)mySocketPermissionIntersect.Copy();

     if (mySocketPermissionIntersectCopy.Equals(mySocketPermissionIntersect)){
     Console.WriteLine("Copy successfull");
     }


     // Converts a SocketPermission to XML format and then immediately converts it back to a SocketPermission.
     mySocketPermission1.FromXml(mySocketPermission1.ToXml());

     // Checks to see if permission for this socket resource is unrestricted.  If it is, then there is no need to
     // demand that permissions be enforced.
     if (mySocketPermissionUnion.IsUnrestricted()){
        
          //Do nothing.  There are no restrictions.
     }
     else{
         // Enforces the permissions found in mySocketPermissionUnion on any Socket Resources used below this statement. 
         mySocketPermissionUnion.Demand();
     }

    IPHostEntry myIpHostEntry = Dns.Resolve("www.contoso.com");
    IPEndPoint myLocalEndPoint = new IPEndPoint(myIpHostEntry.AddressList[0], 11000);

       Socket s = new Socket(myLocalEndPoint.Address.AddressFamily,
                                   SocketType.Stream,
                                         ProtocolType.Tcp);
       try{
            s.Connect(myLocalEndPoint);
       }
       catch (Exception e){
            Console.WriteLine("Exception Thrown: " + e.ToString());
       } 

      // Perform all socket operations in here.
      
      s.Close();