Calculator Code Constructed in "simple factory mode" After Optimization-C # "reflection" Technology

The modified calculator Code has the following problem: If you need to add a new operation class, in addition to modifying the interface code, you also need to add a new statement in the switch of operaationfactory! Using C # reflection technology can solve the problem well. The following code does not use DLL. For example:

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Operation. CS

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Using system;

Using system. Collections. Generic;

Using system. text;

 

Namespace usage

{

/// <Summary>

/// Operation class

/// </Summary>

Public class operation

{

Private double _ numbera = 0;

Private double _ numberb = 0;

 

/// <Summary>

/// Number

/// </Summary>

Public double numbera

{

Get

{

Return _ numbera;

}

Set

{

_ Numbera = value;

}

}

 

/// <Summary>

/// Number B

/// </Summary>

Public double numberb

{

Get

{

Return _ numberb;

}

Set

{

_ Numberb = value;

}

}

 

/// <Summary>

/// Obtain the calculation result

/// </Summary>

/// <Returns> </returns>

Public Virtual double getresult ()

{

Double result = 0;

Return result;

}

 

 

}

 

/// <Summary>

/// Addition class

/// </Summary>

Class operationadd: Operation

{

Public override double getresult ()

{

Double result = 0;

Result = numbera + numberb;

Return result;

}

}

 

/// <Summary>

/// Subtraction class

/// </Summary>

Class operationsub: Operation

{

Public override double getresult ()

{

Double result = 0;

Result = numbera-numberb;

Return result;

}

}

 

/// <Summary>

/// Multiplication class

/// </Summary>

Class operationmul: Operation

{

Public override double getresult ()

{

Double result = 0;

Result = numbera * numberb;

Return result;

}

}

 

/// <Summary>

/// Division class

/// </Summary>

Class operationdiv: Operation

{

Public override double getresult ()

{

Double result = 0;

If (numberb = 0)

Throw new exception ("the divisor cannot be 0. ");

Result = numbera/numberb;

Return result;

}

}

 

/// <Summary>

/// Computing Factory

/// </Summary>

Class operationfactory

{

Public static operation createoperate (string operate)

{

Operate = "operator." + operate;

Operation operation;

Object OBJ = activator. createinstance (type. GetType (operate ));

Operator = (operation) OBJ;

Return response;

}

}

 

}

----------------------------------------- Program. CS ----------------------------------------- using system; using system. collections. generic; using system. text; namespace detail {class program {static void main (string [] ARGs) {// operationadd operationsub operationmul operationdiv operation; while (true) {console. write ("Enter the number A:"); string strnumbera = console. readline (); // select the operator to read from the configuration file XML // console. write ("Please select the operator number:/noperationadd represents plus (+)/noperationsub represents minus (-)/noperationmul represents multiplication (*)/noperationdiv represents Division (/) /n "); string stroperate = console. readline (); operator = operationfactory. createoperate (stroperate); console. write ("Enter the number B:"); string strnumberb = console. readline (); iterator. numbera = convert. todouble (strnumbera); random. numberb = convert. todouble (strnumberb); double result = random. getresult (); console. writeline ("Result:" + result );}}}}