< Chap 15 TOC: Some advancement in the .NET framework Networking | Main | VB .NET & C++/CLI Network Data Collection Examples >
Chapter 15 Part 1:
Advancements in .NET Framework Networking
What do we have in this chapter 15 Part 1?
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The FTP Protocol and Message Queuing (MSMQ)
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Protocol Independence
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Network Awareness
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Collecting and Displaying the Network Info C# Program Example
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Adding References
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Build and Run the C# Project
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This chapter will talk about the current and possible emerging trends in the world of distributed application development and related enhancements in the Microsoft .NET Framework. Reviewing these trends will illuminate steps that you can take today as you architect solutions to ensure they will be poised to take advantage of the new technology. In most cases, the .NET Framework already provides significant support for each of these trends. However, it is useful to recognize where the key focal points will be in the future.
The FTP Protocol and Message Queuing (MSMQ)
Customers of the .NET Framework versions 1 and 1.1 said they wanted the framework to support the File Transfer Protocol (FTP). In response to this feedback, FTP support was already available from the framework’s newer release which can be found in the following links:
Third party options are already available before this as an example can be found at the following sites:
Another way to add asynchronous processing to your Microsoft .NET application is using (Microsoft) Message Queuing (MSMQ) which is a typical implementation for Microsoft email and messaging systems. You can use the System.Messaging classes provided by the .NET Framework to work with MSMQ and at the same time can add asynchronous workflow to your application. Have a peek at the MSMQ simple example using VB on how to access Message Queues.
Protocol Independence
As discussed in Chapter 11, a specific protocol such as HTTP is not the optimal tool for every situation faced by today’s distributed applications. Maintaining protocol independence while still achieving interoperability is an increasingly important and achievable aspect to distributed application development. |
Each protocol in use on the network today comes with its own set of strengths and weaknesses. Applications with the agility to switch from one transport to another will be in demand as user needs evolve. To take advantage of this trend, the core functionality of your applications should be independent of the underlying transport protocol. The .NET Framework helps developers design applications with greater protocol independence by providing common I/O models, such as the System.IO.Stream type. Going forward, you can expect to see further enhancements in the System.Net namespace and in other areas of the .NET Framework, such as Web services that support this trend.
Network Awareness
Although applications have had to interact with the network for many years, few have done a good job of staying aware of the network and dynamically changing their behavior to best suit current conditions. For example, today’s smart client applications are considered advanced if they simply support an online/offline mode. While being aware of online/offline status is an important part of unity with the network, applications can do much more. For example, an application that is aware of network characteristics, such as connection speed and throughput between local and remote endpoints, can provide a much richer experience than an application that simply goes “offline” when the network is slow. Imagine an application that is written in such a way that it works with minimal reliance on the network in low bandwidth conditions, but automatically senses increases in speed and throughput and reacts accordingly to improve the user experience. What’s more, this application could use network “fingerprinting” techniques to recognize different network configurations and remember which services were available the last time it ran on them or even associate a geographical location with that network.
Developers building .NET applications should be aware of the potential for network awareness and plan for it in an application. For example, you should consider factoring protocol logic and business logic into the application in such a way that the network intensive protocols can be used in high bandwidth cases, but the application can have a fallback in lower bandwidth scenarios. If your application is rich in information that comes across a network, consider factoring the way your application uses the network into different profiles or buckets and providing scaled-down experiences for your users. A scaled-down experience is preferable to having a user wrestle with an application that was designed for a LAN from a dial-up connection. Today, the .NET Framework enables applications to address network elements such as connection speed and network connectivity through the System.Management classes. The following code sample demonstrates how to determine whether a machine has one or more valid IP addresses assigned, which can indicate the machine’s network connectivity:
C#
using System;
using System.Management;
/// <summary>
/// This sample demonstrates the use of System.Management
/// to detect whether one or more valid network
/// connections are associated with the machine.
/// </summary>
class NetworkInformation
{
[STAThread]
static void Main(string[ ] args)
{
// Check to see whether one or more connections
// are assigned to this machine (based on IP address)
int numConnections = GetNumAvailableConnections();
if(numConnections > 0)
{
if(numConnections == 1)
{
Console.WriteLine("1 connection on this machine with ");
Console.WriteLine("at least 1 valid IP address assigned");
}
else
{
Console.WriteLine(numConnections + " connections on this ");
Console.WriteLine("machine with at least 1 valid IP address");
}
}
else
{
Console.WriteLine("No cards found with a valid IP address");
}
}
public static int GetNumAvailableConnections()
{
// Query for the list of network adapters on the machine
// For more detail on this type you can search
// http://msdn.microsoft.com for "Win32_NetworkAdapterConfiguration"
SelectQuery NAQuery = new SelectQuery("select * from " +
"Win32_NetworkAdapterConfiguration");
ManagementObjectSearcher NASearcher = new ManagementObjectSearcher(NAQuery);
int availableConnections = 0;
try
{
// Loop through each adapter returned from the query
foreach (ManagementObject enumerate in NASearcher.Get())
{
// Find out whether IP is enabled on this adapter
bool IPEnabled = (bool)enumerate["IPEnabled"];
// Get the adapter description
Console.WriteLine((string)enumerate["Caption"]);
// If the IP is enabled check for non-zero IP
if(IPEnabled)
{
string[ ] IPAddress = (string[ ])enumerate["IPAddress"];
Console.WriteLine("IP Address: " + IPAddress[0]);
if(IPAddress[0] != "0.0.0.0")
{
availableConnections++;
}
}
Console.WriteLine();
}
}
catch(Exception e)
{
Console.WriteLine(e.ToString());
}
return availableConnections;
}
}
Visual Basic .NET
Imports System
Imports System.Management
'This sample demonstrates the use of System.Management
'to detect whether one or more valid network
'connections are associated with the machine.
Module NetworkInformation
Sub Main()
' Check to see whether one or more connections
' are assigned to this machine (based on IP address)
Dim numConnections As Integer
numConnections = GetNumAvailableConnections()
If numConnections > 0 Then
If (numConnections = 1) Then
Console.WriteLine("1 connection on this machine with")
Console.WriteLine("at least 1 valid IP address assigned")
Else
Console.WriteLine(numConnections & " connections on this ")
Console.WriteLine("machine with at least 1 valid IP address")
End If
Else
Console.WriteLine("No cards found with a valid IP address")
End If
End Sub
Function GetNumAvailableConnections() As Integer
' Query for the list of network adapters on the machine
' For more detail on this type you can search
' http://msdn.microsoft.com for "Win32_NetworkAdapterConfiguration"
Dim NAQuery As SelectQuery
NAQuery = New SelectQuery("select * from " & _
"Win32_NetworkAdapterConfiguration")
Dim NASearcher As ManagementObjectSearcher
NASearcher = New ManagementObjectSearcher(NAQuery)
Dim availableConnections As Integer
Try
' Loop through each adapter returned from the query
Dim enumerate As ManagementObject
For Each enumerate In NASearcher.Get()
' Find out whether IP is enabled on this adapter
Dim IPEnabled As Boolean
IPEnabled = enumerate("IPEnabled")
' Get the adapter description
Console.WriteLine(enumerate("Caption"))
' If IP is enabled then check for a non-zero IP
If IPEnabled Then
Dim IPAddress As String()
IPAddress = enumerate("IPAddress")
Console.WriteLine("IP Address: " & IPAddress(0))
If IPAddress(0) <> "0.0.0.0" Then
availableConnections = availableConnections + 1
End If
End If
Console.WriteLine()
Next
Catch e As Exception
Console.WriteLine(e.ToString())
End Try
Return availableConnections
End Function
End Module
This code uses the System.Management classes to query the system for installed network adapters and then inspect each adapter for associated IP addresses. This behavior is expected to be improved with richer and easier to find information in future releases of the .NET Framework. The following section presents the complete C#, VB .NET and C++/CLI program examples.
Collecting and Displaying the Network Info C# Program Example
Create a new C# console application. You can use the solution and project names as shown in the following screenshot.
Add/edit code as given below.
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using System; using System.Management;
namespace NetworkConnectionCS { /// <summary> /// This sample demonstrates the use of System.Management /// to detect whether or not one or more valid network /// connections is associated with the machine. /// </summary> class NetworkInformation { [STAThread] static void Main(string[ ] args) { // Check to see if there is one or more connections // assigned to this machine (based on IP address) int numConnections = GetNumAvailableConnections(); if (numConnections > 0) { if (numConnections == 1) { Console.WriteLine("1 connection on this machine with "); Console.WriteLine("at least 1 valid IP address assigned"); } else { Console.WriteLine(numConnections + " connections on this "); Console.WriteLine("machine with at least 1 valid IP address"); } } else { Console.WriteLine("No cards found with a valid IP address"); } }
public static int GetNumAvailableConnections() { // Query for the list of network adapters on the machine // Note for more detail on this type you can search // for "Win32_NetworkAdapterConfiguration": // http://msdn.microsoft.com/en-us/library/aa394217(VS.85).aspx SelectQuery NAQuery = new SelectQuery("select * from Win32_NetworkAdapterConfiguration"); ManagementObjectSearcher NASearcher = new ManagementObjectSearcher(NAQuery); int availableConnections = 0;
try { // Loop through each adapter returned from the query foreach (ManagementObject enumerate in NASearcher.Get()) { // Find out if IP is enabled on this adapter bool IPEnabled = (bool)enumerate["IPEnabled"]; // Get the adapter description Console.WriteLine((string)enumerate["Caption"]); // If the IP is enabled check for non-zero IP if (IPEnabled) { string[ ] IPAddress = (string[ ])enumerate["IPAddress"]; Console.WriteLine("IP Address: " + IPAddress[0]); if (IPAddress[0] != "0.0.0.0") { availableConnections++; } } Console.WriteLine(); } } catch (Exception e) { Console.WriteLine(e.ToString()); } return availableConnections; } } } |
If the System.Management namespaces cannot resolve the following types, we need to add the reference manually.
Adding References
Invoke the Add Reference page.
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Then, from the .NET page, find and select the System.Management component and click OK.
Build and Run the C# Project
Next, build the project and make sure there is no error.
Then, run the project without debugging.
The following screenshot shows a sample output.
< Chap 15 TOC: Some advancement in the .NET framework Networking | Main | VB .NET & C++/CLI Network Data Collection Examples >