Archive of: C#
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Using Extension Methods in .NET posted September 3, 2010
Extension methods are a handy way of adding your own custom methods to a class when you normally wouldn’t be able to. .NET treats extension methods exactly like instance methods. In fact, in your day-to-day .NET programming you may be calling extension methods and not even know it.
Let’s say we have access to an API with a simple Person class. Also, for the purposes of this post, let’s say we don’t have access to extend or modify this class.
public class Person { public Person(string first, string middle, string last) { FirstName = first; MiddleName = middle; LastName = last; } public string FirstName { get; set; } public string MiddleName { get; set; } public string LastName { get; set; } }In order to get the full name of a Person we’d have to do something like this:
Person p = new Person("Robert", "N", "Greiner"); string fullName = String.Format("{0} {1}", p.FirstName, p.LastName);This is perfectly fine, but what if you have to do this in several places? You’d either have to copy/paste this code wherever you needed it (bad idea, what if your boss came in later and said that she… Read the rest
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Grouping Radio Buttons in ASP .NET MVC 2 posted August 27, 2010
Here’s a simple issue I ran into today when dealing with radio buttons in an ASP .NET MVC 2 application.
Radio buttons should only allow the user to select a single option out of multiple choices. This should be enforced by only allowing one radio button to be selected for each option set. But, what if your application has multiple options that all need radio buttons? How do you distinguish the radio buttons from one option from the other.
This is where groups comes in. By setting the GroupName property for each of your radio buttons, you can specify which buttons to associate to an option.
<div> <asp:RadioButton ID="ActionMatch" GroupName="RegexActions" Checked="true" Text="Match" runat="server" /> <asp:RadioButton ID="ActionReplace" GroupName="RegexActions" Text="Replace" runat="server" /> </div>
Also, note that in ASP .NET MVC 2 there is no default group, so you must define a GroupName in order for the radio buttons to work properly.
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Using Stopwatches and Timers in .NET posted June 2, 2010
Two problems that plague new programmers and seasoned professionals alike is the need to delay program execution and get an accurate time how long something takes to execute. Luckily, there are probably a few thousand ways to solve each problem. Unfortunately, most of them center around laziness (the bad kind) and unreliability. In this article, I’ll attempt to show you how to implement the different Timer and Stopwatch classes in .NET to help ensure your application will work as intended for years to come. Because, let’s face it, you probably aren’t going to be re-factoring any time soon.
Timers
First, we’ll start of with an introduction to Timers and how not to implement them. Timers allow you to control the execution of your application by being able to define when an action takes place.
I remember in my very first high-school programming class, we were instructed to move a circle from one end of the screen to the other. The problem every student eventually encountered was, the circle had already moved to the edge of the screen by the time the graphics got loaded and we didn’t get to see any animation. This happened because the function that incremented… Read the rest
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Iterating Through a Dictionary in C# posted May 23, 2010
A Dictionary allows you to store items in a collection using a key/value paring. By storing your data this way, you get all of the functionality of a standard .NET Collection with the added benefits of Hashing.
I’m going to start off by showing you how to get data into a Dictionary. Then, I’ll move on to how to access specific data entries. And, finally, I’ll demonstrate two methods of iterating through the Dictionary. This should give you enough information to get started with Dictionaries if you’ve never seen them before, and hopefully, teach you something new if you are already familiar with them.
Inserting Into a Dictionary
First, let’s get some data into our Dictionary by adding some of the hard workers of Dunder Mifflin.
Dictionary<int, Person> employees = new Dictionary<int, Person>(); employees.Add(1000, new Person("Jim Halpert")); employees.Add(1001, new Person("Pam Halpert")); employees.Add(1002, new Person("Andy Bernard")); employees.Add(1003, new Person("Dwight Schrute")); employees.Add(1004, new Person("Michael Scott"));Retrieving Data From a Dictionary
Now that we have our employees in memory, we can access them in near constant time (O(1)) by using their ID.
Person p = employees[1003]; //Select Dwight
Iterating Through a Dictionary… Read the rest
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Write Better Code: Using Nullable With C# posted April 20, 2010
I’m sure if you have ever written code for more than 45 seconds, you have more than likely come across a need to check whether or not a variable has been assigned a value.
This is probably how about 99% of us do it:
int age = 0; //some code that gets user input if (age == 0) { Console.WriteLine("Fail! Please enter a valid age."); } else { Console.WriteLine("You are now " + age + " years old"); }The above code is bad for three reasons:
- The code is error prone. Why do things on your own, when the language provides a simple consistent way of doing things?
- The code isn’t standardized. What if you assign 0 as the official “un-assigned” check for all of your strings, but Johnny Programmer (in his super awesome wisdom) decides to initialize all of his un-assigned integers with -1, then what? Now you are forced to add unnecessary rules to your coding standards to ensure yours and Johnny’s code plays together nicely. This is lame.
- The code isn’t optimized. The fewest amount of bits to compare per if statement the better. why compare multiple Bytes when you can