Skip to main content

C# - .NET 3.5 Adds Named Pipes Support [Beginner]


Leave it to Microsoft to make all my hard work worthless. It took a lot of hard work and a lot of Windows API calls to get named pipes integrated into a .NET 2.0 application. Now, thanks to .NET 3.5, named pipes are as easy as importing System.IO.Pipes.

If you want a named pipe server, all you have to do is create some instances of NamedPipeServerStream to handle each client connection. I stole the following code straight from the MSDN documentation.
using System;
using System.IO;
using System.IO.Pipes;

class PipeServer
{
  static void Main()
  {
    using (NamedPipeServerStream pipeServer =
        new NamedPipeServerStream("testpipe", PipeDirection.Out))
    {
      Console.WriteLine("NamedPipeServerStream object created.");

      // Wait for a client to connect
      Console.Write("Waiting for client connection...");
      pipeServer.WaitForConnection();

      Console.WriteLine("Client connected.");
      try
      {
        // Read user input and send that to the client process.
        using (StreamWriter sw = new StreamWriter(pipeServer))
        {
          sw.AutoFlush = true;
          Console.Write("Enter text: ");
          sw.WriteLine(Console.ReadLine());
        }
      }
      // Catch the IOException that is raised if the pipe is 
      // broken or disconnected.
      catch (IOException e)
      {
        Console.WriteLine("ERROR: {0}", e.Message);
      }
    }
  }
}
 
Just like most .NET streams, the NamedPipeServerStream supports both synchronous and asynchronous communication. The stream is also full duplex, meaning it can be read and written to at the same time. Getting the overlapped IO working was one of the biggest challenges to overcome for named pipes in previous versions of .NET.

Making a client is just as easy as the server. The Pipes namespace has another stream, called NamedPipeClientStream, which does all the work for you.
using System;
using System.IO;
using System.IO.Pipes;

class PipeClient
{
  static void Main(string[] args)
  {
    using (NamedPipeClientStream pipeClient =
        new NamedPipeClientStream(".", "testpipe", PipeDirection.In))
    {

      // Connect to the pipe or wait until the pipe is available.
      Console.Write("Attempting to connect to pipe...");
      pipeClient.Connect();

      Console.WriteLine("Connected to pipe.");
      Console.WriteLine("There are currently {0} pipe server instances open.",
         pipeClient.NumberOfServerInstances);
      using (StreamReader sr = new StreamReader(pipeClient))
      {
        // Display the read text to the console
        string temp;
        while ((temp = sr.ReadLine()) != null)
        {
          Console.WriteLine("Received from server: {0}", temp);
        }
      }
    }
    Console.Write("Press Enter to continue...");
    Console.ReadLine();
  }
}
 
When I get a chance to use these objects a little more, I'll post a more in-depth tutorial. Personally, I'd like to see a set of objects similar to the TcpClient and TcpServer classes for handling named pipes, but I guess I'll have to wait a little longer for that.
Labels:

Comments

Post a Comment

Popular posts from this blog

C# Snippet - Shuffling a Dictionary [Beginner]

Randomizing something can be a daunting task, especially with all the algorithms out there. However, sometimes you just need to shuffle things up, in a simple, yet effective manner. Today we are going to take a quick look at an easy and simple way to randomize a dictionary, which is most likely something that you may be using in a complex application. The tricky thing about ordering dictionaries is that...well they are not ordered to begin with. Typically they are a chaotic collection of key/value pairs. There is no first element or last element, just elements. This is why it is a little tricky to randomize them. Before we get started, we need to build a quick dictionary. For this tutorial, we will be doing an extremely simple string/int dictionary, but rest assured the steps we take can be used for any kind of dictionary you can come up with, no matter what object types you use. Dictionary < String , int > origin = new Dictionary < string , int >();
1 comment
Read more

C# Snippet - The Many Uses Of The Using Keyword [Beginner]

What is the first thing that pops into your mind when you think of the using keyword for C#? Probably those lines that always appear at the top of C# code files - the lines that import types from other namespaces into your code. But while that is the most common use of the using keyword, it is not the only one. Today we are going to take a look at the different uses of the using keyword and what they are useful for. The Using Directive There are two main categories of use for the using keyword - as a "Using Directive" and as a "Using Statement". The lines at the top of a C# file are directives, but that is not the only place they can go. They can also go inside of a namespace block, but they have to be before any other elements declared in the namespace (i.e., you can't add a using statement after a class declaration). Namespace Importing This is by far the most common use of the keyword - it is rare that you see a C# file that does not h
Post a Comment
Read more

C# WPF Printing Part 2 - Pagination [Intermediate]

About two weeks ago, we had a tutorial here at SOTC on the basics of printing in WPF . It covered the standard stuff, like popping the print dialog, and what you needed to do to print visuals (both created in XAML and on the fly). But really, that's barely scratching the surface - any decent printing system in pretty much any application needs to be able to do a lot more than that. So today, we are going to take one more baby step forward into the world of printing - we are going to take a look at pagination. The main class that we will need to do pagination is the DocumentPaginator . I mentioned this class very briefly in the previous tutorial, but only in the context of the printing methods on PrintDialog , PrintVisual (which we focused on last time) and PrintDocument (which we will be focusing on today). This PrintDocument function takes a DocumentPaginator to print - and this is why we need to create one. Unfortunately, making a DocumentPaginator is not as easy as
Post a Comment
Read more