步步为营 .NET 代码重构学习笔记十一

小鱼儿 2021-12-23 00:55 208阅读 0赞

步步为营 .NET 代码重构学习笔记系列

[步步为营 .NET 代码重构学习笔记 一、为何要代码重构][.NET _]

[步步为营 .NET 代码重构学习笔记 二、提炼方法(Extract Method)][.NET _ _Extract Method]

[步步为营 .NET 代码重构学习笔记 三、内联方法(Inline Method)][.NET _ _Inline Method]

[步步为营 .NET 代码重构学习笔记 四、临时变量(Temporary Variable)][.NET _ _Temporary Variable]

[步步为营 .NET 代码重构学习笔记 五、分解函数和替换算法(Replace Method And Substitute Algorithm)][.NET _ _Replace Method And Substitute Algorithm]

[步步为营 .NET 代码重构学习笔记 六、移动函数和移动值域(Move Method And Move Field)][.NET _ _Move Method And Move Field]

[步步为营 .NET 代码重构学习笔记 七][.NET _ 1]

[步步为营 .NET 代码重构学习笔记 八][.NET _ 2]

[步步为营 .NET 代码重构学习笔记 九][.NET _ 3]

[步步为营 .NET 代码重构学习笔记 十][.NET _ 4]

**一、Remove Control Flag（移除控制标记）**

**动机（Motivation）**

以break语句或return语句取代控制标记。

**示例**

public void CheckSecurity(string[] people)
            {
                string found = string.Empty;
                for (int i = 0; i < people.Length; i++)
                {
                    if (found.Equals(""))
                    {
                        if (people[i].Equals("Don"))
                        {
                            found = "Don";
                        }
                        if (people[i].Equals("John"))
                        {
                            found = "John";
                        }
                    }
                }
                SomeDataCode(found);
            }

改为

public void CheckSecurity(string[] people)
            {
                string found = string.Empty;
                for (int i = 0; i < people.Length; i++)
                {
                    if (found.Equals(""))
                    {
                        if (people[i].Equals("Don"))
                        {
                            found = "Don";
                            break;
                        }
                        if (people[i].Equals("John"))
                        {
                            found = "John";
                            break;
                        }
                    }
                }
                SomeDataCode(found);
            }

**示例**

public string FindPeople(string[] people)
            {
                string found = string.Empty;
                for (int i = 0; i < people.Length; i++)
                {
                    if (found.Equals(""))
                    {
                        if (people[i].Equals("Don"))
                        {
                            found = "Don";                      
                        }
                        if (people[i].Equals("John"))
                        {
                            found = "John";                      
                        }
                    }
                }
                return found;
            }

改为

public string FindPeople(string[] people)
            {
                string found = string.Empty;
                for (int i = 0; i < people.Length; i++)
                {
                    if (found.Equals(""))
                    {
                        if (people[i].Equals("Don"))
                        {
                            return "Don";
                        }
                        if (people[i].Equals("John"))
                        {
                            return "John";
                        }
                    }
                }
                return string.Empty;
            }

**二、Replace Nested Conditional with Guard Clauses（以卫语句取代嵌套条件式）**

**动机（Motivation）**

使用卫语句（guard clauses）表现所有特殊情况。

**示例**

public double GetPayAmount()
            {
                double result;
                if (IsDead)
                    result = DeadAmount();
                else
                {
                    if (IsSeparated)
                        result = SeparatedAmount();
                    else
                    {
                        if (IsRetired)
                            result = RetiredPayAmount();
                        else
                            result = NormalPayAmount();
                    }
                }
                return result;
            }

改为

public double GetPayAmount()
            {
                if (IsDead)
                    return DeadAmount();
                if (IsSeparated)
                    return SeparatedAmount();
                if (IsRetired)
                    return RetiredPayAmount();
                return NormalPayAmount();
            }

**三、Introduce Null Object （引入Null对象）**

**动机（Motivation）**

将null value（无效值）替换为null object（无效物）

**示例**

if (customer == null)
                    plan = BillingPlan.Basic();
                else
                    plan = customer.GetPlan();

改为

public double GetPayAmount()
            {
                if (customer.IsNull())
                    plan = BillingPlan.Basic();
                else
                    plan = customer.GetPlan();
            }

**四、Rename Method（重新命名函数）**

**动机（Motivation）**

修改函数名称让它人容易理解它的作用

**示例**

public int Getinvcdtlmt()
            {
                return 10;
            }

改为

public int GetInvoiceAbleCreditLimit()
            {
                return 10;
            }

**五、Separate Query from Modifier（将查询函数和修改函数分离）**

**动机（Motivation）**

建立两个不同的函数，其中一个负责查询，另一个负责修改。

**示例**

public string FindPeople(string[] people)
            {
                string found = string.Empty;
                for (int i = 0; i < people.Length; i++)
                {
                    if (found.Equals(""))
                    {
                        if (people[i].Equals("Don"))
                        {
                            SendMail();
                            return "Don";
                        }
                        if (people[i].Equals("John"))
                        {
                            SendMail();
                            return "John";
                        }
                    }
                }
                return string.Empty;
            }

改为

public string FindPeople(string[] people)
            {
                string found = FindPeopleOne(people);
                SendMailToPeople(found);
            }
    
            public string FindPeopleOne(string[] people)
            {
                string found = string.Empty;
                for (int i = 0; i < people.Length; i++)
                {
                    if (found.Equals(""))
                    {
                        if (people[i].Equals("Don"))
                        {
                            return "Don";
                        }
                        if (people[i].Equals("John"))
                        {
                            return "John";
                        }
                    }
                }
                return string.Empty;
            }
    
            public void SendMailToPeople(string people)
            {
                if (!string.IsNullOrEmpty(people))
                    SendMail();
            }

**六、Parameterize Method（令函数携带参数）**

**动机（Motivation）**

建立单一函数，以参数表达那些不同的值

**示例**

public double TenPercentRaise()
            {
                return salary * 1.1;
            }
    
            public double FivePercentRaise()
            {
                return salary * 1.05;
            }

改为

public double Raise(double factor)
            {
                return salary * factor;
            }

**七、Replace Parameter with Explicit Methods（以明确函数取代参数）**

**动机（Motivation）**

针对该参数的每一个可能值，建立一个独立函数。

**示例**

private int _height;
            private int _width;
    
            public void SetValue(string name, int value)
            {
                if (name.Equals("height"))
                {
                    _height = value;
                    return;
                }
                if (name.Equals("width"))
                {
                    _width = value;
                    return;
                }
            }

改为

private int _height;
            private int _width;
    
            public int Height
            {
                set { _height = value; }
            }
    
            public int Width
            {
                set { _width = value; }
            }

转载于:https://www.cnblogs.com/springyangwc/archive/2011/06/01/2067443.html

[.NET _]: http://www.cnblogs.com/springyangwc/archive/2011/05/11/2043845.html
[.NET _ _Extract Method]: http://www.cnblogs.com/springyangwc/archive/2011/05/15/2047218.html
[.NET _ _Inline Method]: http://www.cnblogs.com/springyangwc/archive/2011/05/16/2048105.html
[.NET _ _Temporary Variable]: http://www.cnblogs.com/springyangwc/archive/2011/05/18/2050514.html
[.NET _ _Replace Method And Substitute Algorithm]: http://www.cnblogs.com/springyangwc/archive/2011/05/23/2054716.html
[.NET _ _Move Method And Move Field]: http://www.cnblogs.com/springyangwc/archive/2011/05/23/2054774.html
[.NET _ 1]: http://www.cnblogs.com/springyangwc/archive/2011/05/25/2057529.html
[.NET _ 2]: http://www.cnblogs.com/springyangwc/archive/2011/05/30/2062474.html
[.NET _ 3]: http://www.cnblogs.com/springyangwc/archive/2011/05/30/2063832.html
[.NET _ 4]: http://www.cnblogs.com/springyangwc/archive/2011/05/31/2065261.html