Step by step. NET code refactoring study note 9

1. Duplicate Observed Data (copy [monitored Data])

Motivation)

Copy the data to a domain object. Create an Observer mode to synchronize and control repeated data in domain object and GUI object (sync ).

Example

Html "> step-by-step. NET Design Mode Study note 12, Observer (Observer Mode)

2. Change Unidirectional Association to Bidirectional (Change one-way Association to two-way Association)

Motivation)

Add a counter pointer and enable the modifiers function to update two connections at the same time.

Example

Public class Order
{
Private Customer _ customer;

Public Customer NewCustomer
{
Get {return _ customer ;}
Set {_ customer = value ;}
}
}

Public class Customer
{
}

Change

Public class Order
{
Public List <Customer> CustomerList = new List <Customer> ();

Public void AddCustomer (Customer arg)
{
Arg. orderlist. Add (this );
CustomerList. Add (arg );
}

Public void RemoveCustomer (Customer arg)
{
Arg. orderlist. Remove (this );
CustomerList. Remove (arg );
}
}

Public class Customer
{
Public List <Order> orderlist = new List <Order> ();
Public void AddOrder (Order arg)
{
Arg. CustomerList. Add (this );
Orderlist. Add (arg );
}
Public void RemoveOrder (Order arg)
{
Arg. CustomerList. Remove (this );
Orderlist. Remove (arg );
}
}

 

3. Change Bidirectional Association to Unidirectional (Change Bidirectional to Unidirectional)

Motivation)

There is a two-way association between the two classes, but one class does not need the features of the other class.

Example

Public class Order
{
Public List <Customer> CustomerList = new List <Customer> ();

Public void AddCustomer (Customer arg)
{
Arg. orderlist. Add (this );
CustomerList. Add (arg );
}

Public void RemoveCustomer (Customer arg)
{
Arg. orderlist. Remove (this );
CustomerList. Remove (arg );
}
}

Public class Customer
{
Public List <Order> orderlist = new List <Order> ();
Public void AddOrder (Order arg)
{
Arg. CustomerList. Add (this );
Orderlist. Add (arg );
}
Public void RemoveOrder (Order arg)
{
Arg. CustomerList. Remove (this );
Orderlist. Remove (arg );
}
}

 

Change

Public class Order
{
Private Customer _ customer;

Public Customer NewCustomer
{
Get {return _ customer ;}
Set {_ customer = value ;}
}
}

Public class Customer
{
}

 

Iv. Replace Magic Number with Symbolic Constant (use a Symbolic or literal Constant to obtain the Number of tokens Magic)

Motivation)

Create a constant, name it according to its meaning, and replace the preceding literal value with this constant.

Example

Public double PotentialEnergy (double mass, double height)
{
Return mass * 9.51 * height;
}

 

Change

Private double GRAVITATIONAL_CONSTANT = 9.51;
Public double PotentialEnergy (double mass, double height)
{
Return mass * GRAVITATIONAL_CONSTANT * height;
}

 

 

5. Encapsulate Field (encapsulation value range)

Motivation)

Declare it as private and provide the corresponding accessors)

Example

Public string _ name;

 

Change

Private string _ name;

Public string Name
{
Get {return _ name ;}
Set {_ name = value ;}
}

 

6. Replace Type Code with Class (Replace Type Code with Class)

Motivation)

Replace the Value type code with a new class)

Example

Public class Person
{
Public int O = 0;
Public int A = 1;
Public int B = 2;
& N