MSDN’s documentation for the List(T).Find method shows a clean and concise example of finding a string in a List<string>.  However it is not helpful when you want to locate a custom object in a List<> of custom objects.  For that we need to create a delegate method.  The following example uses an anonymous delegate method for a cleaner coding approach.  It’s been tested in Snippet Compiler 2.0.8.3. 

   1:  using System;
   2:  using System.Collections.Generic;
   3:   
   4:   
   5:   
   6:  /// <summary>
   7:  /// Demonstration using delegate method to find custom object in List<>
   8:  /// </summary>
   9:  public class MyClass {
  10:     public static List<Dept> Depts = new List<Dept>();
  11:   
  12:     public static void Main() {
  13:        Dept dept = new Dept();
  14:   
  15:        // We seed the List<> with some departments for demo purposes
  16:        Depts.Add(new Dept("sales"));
  17:        Depts.Add(new Dept("marketing"));
  18:        Depts.Add(new Dept("accounting"));
  19:   
  20:   
  21:        // Assume input for next two blocks came from a db query, user input, etc
  22:        dept = Dept.GetByName(Depts, "sales");
  23:        if(dept == null) {
  24:           dept = new Dept("sales");
  25:           Depts.Add(dept);
  26:        }
  27:   
  28:        dept = Dept.GetByName(Depts, "production");
  29:        if(dept == null) {
  30:           dept = new Dept("production");
  31:           Depts.Add(dept);
  32:        }
  33:   
  34:        
  35:        // Iterate Depts<> and echo out departments.  Note that sales did not get
  36:        // added a second time
  37:        foreach(Dept d in Depts) {
  38:           WL(d.DeptName + "\n");
  39:        }
  40:   
  41:        // Hit enter to close the console
  42:        RL();
  43:     }
  44:   
  45:   
  46:   
  47:     #region Helper methods
  48:   
  49:     private static void WL(object text, params object[] args) {
  50:        Console.WriteLine(text.ToString(), args);
  51:     }
  52:   
  53:     private static void RL() {
  54:        Console.ReadLine();
  55:     }
  56:   
  57:     private static void Break() {
  58:        System.Diagnostics.Debugger.Break();
  59:     }
  60:   
  61:     #endregion
  62:  }
  63:   
  64:   
  65:   
  66:  /// <summary>
  67:  /// Simple Class implements a department object with just name and id plus a
  68:  /// delegate method GetByName() that returns an object from a List<> based on
  69:  /// the objects DeptName property.
  70:  /// </summary>
  71:  public class Dept {
  72:     public string DeptName;
  73:     public long DeptId;
  74:   
  75:     public Dept() {
  76:     }
  77:   
  78:     public Dept(string deptName) {
  79:        DeptName = deptName;
  80:     }
  81:   
  82:     // Returns the first occurance of an object containing the deptName or null
  83:     // if it does not exist
  84:     public static Dept GetByName(List<Dept> list, string deptName) {
  85:        return list.Find(delegate(Dept obj) {
  86:           return obj.DeptName == deptName;
  87:        });
  88:     }
  89:  }