Csharp/C Sharp/LINQ/Extension Method

Add Extension method

<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Text; using System.IO; using System.Reflection; using System.Linq; using System.Xml; using System.Xml.Linq; public static class Extensions {

   public static string SpaceToUnderscore(this string source) {
       char[] cArray = source.ToCharArray();
       string result = null;
       foreach (char c in cArray) {
           if (Char.IsWhiteSpace(c))
               result += "_";
           else
               result += c;
       }
       return result;
   }

} class Program {

   static void Main(string[] args) {
       string s = "This is a test";
       Console.WriteLine(s.SpaceToUnderscore());
   }

}

</source>

Extension method for integer

<source lang="csharp">

using System; static class MainClass {

   public static int ConvertToBase(this int i, int baseToConvertTo) {
       if (baseToConvertTo < 2 || baseToConvertTo > 10)
           throw new ArgumentException("Value cannot be converted to base " + baseToConvertTo.ToString());
       int result = 0;
       int iterations = 0;
       do {
           int nextDigit = i % baseToConvertTo;
           result += nextDigit * (int)Math.Pow(10, iterations);
           iterations++;
           i /= baseToConvertTo;
       }
       while (i != 0);
       return result;
   }
   static void Main() {
       try {
           int x = 591;
           for (int i = 2; i <= 10; i++) {
               Console.WriteLine("{0} in base {1} is {2}", x, i, x.ConvertToBase(i));
           }
       } catch (Exception ex) {
           Console.WriteLine("Exception: {0}", ex.Message);
       }
   }

}

</source>

Extension Methods Discoverability

<source lang="csharp"> using System; class Class1 { } class Class2 {

   public void Method1(string s) {
       Console.WriteLine("Class2.Method1");
   }

} class Class3 {

   public void Method1(object o) {
       Console.WriteLine("Class3.Method1");
   }

} class Class4 {

   public void Method1(int i) {
       Console.WriteLine("Class4.Method1");
   }

} static class Extensions {

   static public void Method1(this object o, int i) {
       Console.WriteLine("Extensions.Method1");
   }
   static void Main() {
       new Class1().Method1(12); // Extensions.Method1 is called
       new Class2().Method1(12); // Extensions.Method1 is called
       new Class3().Method1(12); // Class3.Method1 is called
       new Class4().Method1(12); // Class4.Method1 is called
   }

}

</source>

Object Initializer

<source lang="csharp"> using System; using System.Collections.Generic; using System.Diagnostics; class MyPC {

   public Int32 Id { get; set; }
   public Int64 Memory { get; set; }
   public String Name { get; set; }

} public class MainClass {

   static void Main(string[] args) {
       var processes = new List<MyPC>();
       foreach (var process in Process.GetProcesses()) {
           processes.Add(new MyPC {
               Id = process.Id,
               Name = process.ProcessName, 
               Memory = process.WorkingSet64
           });
       }
   }

}

</source>