Mixin can be implemented in C# 3.0 using an extension method.
Functionality can be added by extending
the interface implemented by the class.
Consider the following example.
1: using System;
2:
3: namespace Mixin
4:
5: { 6:
7: class Person : IPerson
8:
9: { 10:
11: private int _age;
12:
13: private string _name;
14:
15: #region IPerson Members
16:
17: public int age
18:
19: { 20:
a
21: get
22:
23: { 24:
25: return _age;
26:
27: }
28:
29: set
30:
31: { 32:
33: if (value > 0)
34:
35: { 36:
37: _age = value;
38:
39: }
40:
41:
42: }
43:
44: }
45:
46:
47: public string name
48:
49: { 50:
51: get
52:
53: { 54:
55: return _name;
56:
57: }
58:
59: set
60:
61: { 62:
63: if (!string.IsNullOrEmpty(value))
64:
65: { 66:
67: _name = value;
68:
69: }
70:
71: else
72:
73: { 74:
75: _name = "Unknown";
76:
77: }
78:
79: }
80:
81: }
82:
83: #endregion
84:
85: }
86:
87: interface IPerson
88:
89: { 90:
91: int age { get; set; } 92:
93: String name { get; set; } 94:
95: }
96:
97: static class ExtendIPerson
98:
99: { 100:
101: public static bool CanDrive(this IPerson testPerson, bool isDriver)
102:
103: { 104:
105: if (isDriver)
106:
107: return true;
108:
109: return false;
110:
111: }
112:
113: }
114:
115: class Program
116:
117: { 118:
119: static void Main(string[] args)
120:
121: { 122:
123: IPerson ip = new Person();
124:
125:
126: ip.name = "ABC";
127:
128: ip.age = 21;
129:
130: if(ip.CanDrive(true))
131:
132: { 133:
134: Console.WriteLine(ip.name +" can drive");
135:
136: }
137:
138: Console.ReadLine();
139:
140: }
141:
142: }
143:
144: }
145:
In this example, we implemented mixin by extending the IPerson interface
[line 87] using CanDrive extension method defined
in the ExtendIPerson static class[line 101].
Notice the code on line 130 ip.CanDrive - an example of C# mixin.
Another explanation of the mixin can be found at
http://mikehadlow.blogspot.com/2008/05/interface-extension-methods-mixin.html