Posted by: Duncan Mackenzie , MSDN This post applies to Visual C# .NET 2002/2003 Suppose you want to run a command line application, open up another Windows program, or even bring up the default web browser or email program... how can you do this from...

The code is trying to access a member of a reference type variable that is set to null . Given the following class, let's examine some code that could be in the Main method: using System; class Foo { static void Main() { // foo has not been...

C# defines the following character escape sequences: \' - single quote, needed for character literals \" - double quote, needed for string literals \\ - backslash \0 - Unicode character 0 \a - Alert (character 7) \b - Backspace...

In this post I’ll try to answer the most common questions I find on forums and in documentation feedback about C# covariance and contravariance. It’s a big topic for a single blog post, so expect to see a lot of “more information” links. Special thanks...

You can use the Convert class or the Parse method of the built-in type you are casting to. i.e. string myStr = "123"; int myParsedInt = Int32.Parse(myStr); int myConvertedInt = Convert.ToInt32(myStr); This example uses the int type, but you can also...

Visual Studio 2010 is here! And of course this means that C# 4.0 is also here. Let’s do a quick review of the new language features added in this release. Dynamic The dynamic keyword is a key feature of this release. It closes the gap between dynamic...

When performing any action on a control which requires the updating of a user interface element (e.g. setting the Text property on almost any class derived from Control, updating the data source behind a DataGrid), these operations MUST take place on...

Update: Named and optional (default) parameters are available starting from C# 4.0. For more information, see Named and Optional Arguments (C# Programming Guide) . In languages such as C++, a default value can be included as part of the method...

You need to add a reference in your project to an assembly where that namespace is defined. If you are using VS.NET: 1. Right click on the References folder on your project. 2. Select Add Reference. 3. Select the .NET tab (or select the Browse button...

After a quick review of C# language features , let’s do the same for the IDE improvements. So, what’s in there for C# developers? Generate From Usage This feature greatly improves Visual Studio support for test-driven development (TDD) . However...

You have probably already heard about the new dynamic feature in C# 4.0 and how it is used to support COM interop. If you haven't, I strongly recommend reading the following MSDN articles: Using Type dynamic and How to: Access Office Interop Objects by...

By Kevin Pilch-Bisson As Soma mentioned earlier, today we’ve made a Community Technology Preview (CTP) available for download ! The Roslyn project is a forward looking effort to make the wealth of language understanding that the compiler generates...

This blog post explains how to kick off a debugger in a remote machine, programmatically. We are going to use WMI interfaces to achieve this. Use WMI, to start the debuggee process and attach a registered debugger to it using WMI. I have given a sample...

The difference is that the value of a static readonly field is set at run time, and can thus be modified by the containing class, w hereas the value of a const field is set to a compile time constant. In the static readonly case, the containing class...

With this post I want to start a series devoted to the new parallel programming features in .NET Framework 4 and introduce you the Task Parallel Library (TPL) . Update. The list of posts in this series: Getting Started (this post) Task Schedulers and...

It is a common practice to store passwords in databases using a hash. MD5 (defined in RFC 1321 ) is a common hash algorithm, and using it from C# is easy. Here’s an implementation of a method that converts a string to an MD5 hash, which is a 32-character...

The choice between C# and VB.NET is largely one of subjective preference. Some people like C#'s terse syntax, others like VB.NET's natural language, case-insensitive approach. Both have access to the same framework libraries. Both will perform...

Strictly speaking you can't, since const can only be applied to a field or local whose value is known at compile time. In both the lines below, the right-hand is not a constant expression (not in C#). const int [] constIntArray = newint [] {2...

Let’s take a quick look at the object keyword first. I’m not going to talk a lot about it because it’s been around since C# 1.0. This keyword is nothing more than a shortcut for System.Object , which is the root type in the C# class hierarchy. (However...

The Equals method is just a virtual one defined in System.Object , and overridden by whichever classes choose to do so. The == operator is an operator which can be overloaded by classes, but which usually has identity behaviour. For reference...

Use the System.Environment class. Specifically the GetEnvironmentVariable and SetEnvironmentVariable methods. Admitedly, this is not a question specific to C#, but it is one I have seen enough C# programmers ask, and the ability to set environment variables...

Often, you need a way to monitor your applications once they are running on the server or even at the customer site -- away from your Visual Studio debugger. In those situations, it is often helpful to have a simple routine that you can use to log messages...

Expression trees first appeared in Visual Studio 2008, where they were mainly used by LINQ providers. You can use expression trees to represent code in a tree-like format, where each node is an expression. You can also convert expression trees into compiled...

This answer is from Chris Brumme via the following post . I've copied the text in here in case the post disappears. *** There are a number of reasons we don't implement Multiple Implementation Inheritance directly. (As you know, we support Multiple...

This time I want to discuss features that belong to the new System.Collections.Concurrent namespace in the.NET Framework 4. When you design parallel applications, you often need thread-safe data storage as well as some mechanism of sending messages between...