1 using System;
2
3 namespace 泛型委托
4 {
5 class Program
6 {
7 private delegate bool DelCompare(object o1, object o2);
8
9 private delegate bool Compare<T>(T t1, T t2);
10 static void Main(string[] args)
11 {
12 string[] strings = { "C#", "FrameWork", ".net" };
13 int[] ints = { 1, 2, 3, 4, 5 };
14
15 // 1. 普通方法
16 string maxString = GetMaxString(strings);
17 int maxInt = GetMaxInt(ints);
18 Console.WriteLine(maxString);
19 Console.WriteLine(maxInt);
20
21 // 2. 委托方法
22 // 比较麻烦，需要装拆箱
23 object[] strings2 = { "C#", "FrameWork", ".net" };
24 object[] ints2 = { 1, 2, 3, 4, 5 };
25 maxString = (string)GetMax(strings2, CompareString);
26 maxInt = (int)GetMax(
27 ints2,
28 delegate (object o1, object o2)
29 {
30 // 拆箱
31 int i1 = (int)o1;
32 int i2 = (int)o2;
33 return i1 < i2;
34 });
35 Console.WriteLine(maxString);
36 Console.WriteLine(maxInt);
37
38 // 3. 泛型委托
39 // 语法简单，性能高
40 maxString = GetMaxT<string>(strings, (s1, s2) => { return s1.Length < s2.Length; });
41 maxInt = GetMaxT<int>(ints, (i1, i2) => i1 < i2);
42 Console.WriteLine(maxString);
43 Console.WriteLine(maxInt);
44
45 Console.ReadKey();
46 }
47
48 #region 普通方法
49
50 private static string GetMaxString(string[] strings)
51 {
52 string max = strings[0];
53 foreach (var s in strings)
54 {
55 if (max.Length < s.Length)
56 {
57 max = s;
58 }
59 }
60
61 return max;
62 }
63
64 private static int GetMaxInt(int[] ints)
65 {
66 int max = ints[0];
67 foreach (var i in ints)
68 {
69 if (max < i)
70 {
71 max = i;
72 }
73 }
74
75 return max;
76 }
77
78 #endregion
79
80 #region 委托方法
81
82 private static object GetMax(object[] objects, DelCompare del)
83 {
84 object max = objects[0];
85 foreach (var o in objects)
86 {
87 if (del(max, o))
88 {
89 max = o;
90 }
91 }
92
93 return max;
94 }
95
96 private static bool CompareString(object o1, object o2)
97 {
98 string s1 = o1.ToString();
99 string s2 = o2.ToString();
100 return s1.Length < s2.Length;
101 }
102
103 #endregion
104
105 #region 泛型委托
106
107 private static T GetMaxT<T>(T[] ts, Compare<T> compare)
108 {
109 T max = ts[0];
110 foreach (T t in ts)
111 {
112 if (compare(max, t))
113 {
114 max = t;
115 }
116 }
117
118 return max;
119 }
120
121 #endregion
122 }
123 }
