步步为营 .NET 代码重构学习笔记 六
一、Extract Class（提炼类）
动机（Motivation）
一个class应该是一个清楚的抽象（abstract），处理一些明确的责任。但在实际工作中，class会不断成长扩展。这个class会变得过份复杂，很快，class就会变成一团乱麻。
示例
01 public class Person
02 {
03 private string _name;
04 private string _officeAreaCode;
05 private string _officeNumber;
06
07 public string Name
08 {
09 get { return _name; }
10 set { _name = value; }
11 }
12
13 public string OfficeAreaCode
14 {
15 get { return _officeAreaCode; }
16 set { _officeAreaCode = value; }
17 }
18
19 public string OfficeNumber
20 {
21 get { return _officeNumber; }
22 set { _officeNumber = value; }
23 }
24
25 public string TelephoneNumber
26 {
27 get { return "(" + _officeAreaCode + ")" + _officeNumber; }
28 }
29 }
改为
01 public class Person
02 {
03 private string _name;
04 private Telephone _telephoneNumber;
05
06 public Telephone TelephoneNumber
07 {
08 get { return _telephoneNumber; }
09 set { _telephoneNumber = value; }
10 }
11
12 public string Name
13 {
14 get { return _name; }
15 set { _name = value; }
16 }
17
18 public string TemphoneNumber
19 {
20 get { return _telephoneNumber.TelephoneNumber; }
21 }
22
23 }
24 public class Telephone
25 {
26 private string _officeAreaCode;
27 private string _officeNumber;
28 public string OfficeAreaCode
29 {
30 get { return _officeAreaCode; }
31 set { _officeAreaCode = value; }
32 }
33
34 public string OfficeNumber
35 {
36 get { return _officeNumber; }
37 set { _officeNumber = value; }
38 }
39
40 public string TelephoneNumber
41 {
42 get { return "(" + _officeAreaCode + ")" + _officeNumber; }
43 }
44 }
二、Inline Class（将类内联化）
动机（Motivation）
一个class不再承担足够责任、不再有单独存在的理由，将class的所有特性搬移到另一个class中，然后移除原class。
示例
01 public class User
02 {
03 private int _ID;
04 private string _name;
05
06 public int ID
07 {
08 get { return _ID; }
09 set { _ID = value; }
10 }
11
12 public string Name
13 {
14 get { return _name; }
15 set { _name = value; }
16 }
17
18
19 }
20 public class UserInfo
21 {
22 private int _ID;
23 private string _Age;
24
25 public string ID
26 {
27 get { return _ID; }
28 set { _ID = value; }
29 }
30
31 public string Age
32 {
33 get { return _Age; }
34 set { _Age = value; }
35 }
36 }
改为
01 public class User
02 {
03 private int _ID;
04 private string _name;
05 private string _Age;
06
07 public int ID
08 {
09 get { return _ID; }
10 set { _ID = value; }
11 }
12
13 public string Name
14 {
15 get { return _name; }
16 set { _name = value; }
17 }
18
19 public string Age
20 {
21 get { return _Age; }
22 set { _Age = value; }
23 }
24 }
三、Hide Delegate（隐藏[委托关系]）
动机（Motivation）
[封装]即使不是对象的最关键特征，也是最关键特征之一。[封装]意味每个对象都应该尽可能少了解系统的其它部分。如此一来，一旦发生变化，需要了解这变化的对象就会比较少，这会使谈化比较容易进行。
示例
01 public class User
02 {
03 private int _ID;
04 private string _name;
05 private Department _depart;
06
07 public int ID
08 {
09 get { return _ID; }
10 set { _ID = value; }
11 }
12
13 public string Name
14 {
15 get { return _name; }
16 set { _name = value; }
17 }
18
19 public Department Depart
20 {
21 get { return _depart; }
22 set { _depart = value; }
23 }
24
25 }
26
27 public class Department
28 {
29 private string _departName;
30 private User _manager;
31
32 public string DepartName
33 {
34 get { return _departName; }
35 set { _departName = value; }
36 }
37
38 public User Manager
39 {
40 get { return _manager; }
41 set { _manager = value; }
42 }
43 }
改为
01 public class User
02 {
03 private int _ID;
04 private string _name;
05 private Department _depart;
06
07 public int ID
08 {
09 get { return _ID; }
10 set { _ID = value; }
11 }
12
13 public string Name
14 {
15 get { return _name; }
16 set { _name = value; }
17 }
18
19 public Department Depart
20 {
21 get { return _depart; }
22 set { _depart = value; }
23 }
24
25 public string DepartmentManager
26 {
27 get { return _depart.Manager; }
28 }
29 }
30
31 public class Department
32 {
33 private string _departName;
34 private User _manager;
35
36 public string DepartName
37 {
38 get { return _departName; }
39 set { _departName = value; }
40 }
41
42 public User Manager
43 {
44 get { return _manager; }
45 set { _manager = value; }
46 }
47 }
这样取部门管理者就更直接，更方便，适合于少量使用。
但如果有大量的方法都用到了DepartmentManager里，我们就要去掉中间人了。
四、Remove Middle Man（移除中间人）
动机（Motivation）
大量重复的代码是万恶之源。这些重复性代码应该抽出来放进同一个函数中。
示例
01 public class User
02 {
03 private int _ID;
04 private string _name;
05 private Department _depart;
06
07 public int ID
08 {
09 get { return _ID; }
10 set { _ID = value; }
11 }
12
13 public string Name
14 {
15 get { return _name; }
16 set { _name = value; }
17 }
18
19 public Department Depart
20 {
21 get { return _depart; }
22 set { _depart = value; }
23 }
24
25 public string DepartmentManager
26 {
27 get { return _depart.Manager; }
28 }
29 }
30
31 public class Department
32 {
33 private string _departName;
34 private User _manager;
35
36 public string DepartName
37 {
38 get { return _departName; }
39 set { _departName = value; }
40 }
41
42 public User Manager
43 {
44 get { return _manager; }
45 set { _manager = value; }
46 }
47 }
改为
01 public class User
02 {
03 private int _ID;
04 private string _name;
05 private Department _depart;
06
07 public int ID
08 {
09 get { return _ID; }
10 set { _ID = value; }
11 }
12
13 public string Name
14 {
15 get { return _name; }
16 set { _name = value; }
17 }
18
19 public Department Depart
20 {
21 get { return _depart; }
22 set { _depart = value; }
23 }
24
25 }
26
27 public class Department
28 {
29 private string _departName;
30 private User _manager;
31
32 public string DepartName
33 {
34 get { return _departName; }
35 set { _departName = value; }
36 }
37
38 public User Manager
39 {
40 get { return _manager; }
41 set { _manager = value; }
42 }
43 }
在调用时就直接Depart.Manager来取得它的值.
作者： Leo_wl
出处： http://www.cnblogs.com/Leo_wl/
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