extension-methods

I'm used to add methods to external classes like IEnumerable. But can we extend Arrays in C#? I am planning to add a method to arrays that converts it to a IEnumerable even if it is multidimensional. Not related to How to extend arrays in C# static class Extension { public static string Extend(this Array array) { return "Yes, you can"; } } class Program { static void Main(string[] args) { int[,,,] multiDimArray = new int[10,10,10,10]; Console.WriteLine(multiDimArray.Extend()); } } Yes. Either through extending the Array class as already shown, or by extending a specific kind of array or even a

I deal with a framework on a daily basis where we sometimes provide methods that accept IEnumerable<MyBusinessObject> as a parameter in order to show user interfaces, perform calculations etc. If I pass in an array of MyBusinessObject like so: MyBusinessObject[] myArray = new MyBusinessObject { obj1, obj2, ..., objN }; frameworkClass.MyMethod(myArray); .... public class FrameworkClass { public void MyMethod(IEnumerable<MyBusinessObject> objs) { // Other code that uses the enumerable MyBusinessObject[] objectArray = objs.ToArray(); // More code that uses the enumerable } } Does the line objs

I have a class MyClass, and I would like to override the method ToString() of instances of List: class MyClass { public string Property1 { get; set; } public int Property2 { get; set; } /* ... */ public override string ToString() { return Property1.ToString() + "-" + Property2.ToString(); } } I would like to have the following: var list = new List<MyClass> { new MyClass { Property1 = "A", Property2 = 1 }, new MyClass { Property1 = "Z", Property2 = 2 }, }; Console.WriteLine(list.ToString()); /* prints: A-1,Z-2 */ Is it possible to do so? Or I would have to subclass List<MyClass> to override the

The new extensions in .Net 3.5 allow functionality to be split out from interfaces. For instance in .Net 2.0 public interface IHaveChildren { string ParentType { get; } int ParentId { get; } List<IChild> GetChildren() } Can (in 3.5) become: public interface IHaveChildren { string ParentType { get; } int ParentId { get; } } public static class HaveChildrenExtension { public static List<IChild> GetChildren( this IHaveChildren ) { //logic to get children by parent type and id //shared for all classes implementing IHaveChildren } } This seems to me to be a better mechanism for many interfaces.

This question already has an answer here: Anyone know a good workaround for the lack of an enum generic constraint? 12 answers Update: See the bottom of this question for a C# workaround. Hi there, Consider the following extension method: public static bool HasFlags<T>(this T value, T flags) where T : System.Enum { // ... } This will, as you may know, throw an error at compile-time, since a class is not normally allowed to inherit from System.Enum . The problem is that any enumeration specified using the enum keyword does in fact inherit from System.Enum , so the above code would be the ideal

I happened to have seen some code where this guy passed a lambda expression to a ArrayList.Sort(IComparer here) or a IEnumerable.SequenceEqual(IEnumerable list, IEqualityComparer here) where an IComparer or an IEqualityComparer was expected. I can't be sure if I saw it though, or I am just dreaming. And I can't seem to find an extension on any of these collections that accepts a Func<> or a delegate in their method signatures. Is there such an overload/extension method? Or, if not, is it possible to muck around like this and pass an algorithm (read delegate) where a single-method interface is

what's the difference in using tag builder and string builder to create a table in a htmlhelper class, or using the HtmlTable? aren't they generating the same thing?? Bashir Magomedov TagBuilder is a class that specially designed for creating html tags and their content. You are right saying that result will be anyway a string and of course you still can use StringBuilder and the result will be the same, but you can do things easier with TagBuilder . Lets say you need to generate a tag: <a href='http://www.stackoverflow.com' class='coolLink'/> Using StringBuilder you need to write something

Extension methods can be assigned to delegates that match their usage on an object, like this: static class FunnyExtension { public static string Double(this string str) { return str + str; } public static int Double(this int num) { return num + num; } } Func<string> aaMaker = "a".Double; Func<string, string> doubler = FunnyExtension.Double; Console.WriteLine(aaMaker()); //Prints "aa" Console.WriteLine(doubler("b")); //Prints "bb" If the type they're extending is a value type, it won't work: Func<int> eightMaker = 4.Double; //Error CS1113: Extension methods 'FunnyExtension.Double(int)' defined