Articles → .NET DESIGN PATTERN → Factory Method Design Pattern
Factory Method Design Pattern
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Step I - Create the interfaces of product.
// A Simple Interface
public interface iCalc
{
int ReturnResult(int arg1, int arg2);
}
Step II - Create concrete product classes which will
inherit the product interface.
public class Sum : iCalc
{
public int ReturnResult(int arg1, int arg2)
{
return (arg1 + arg2);
}
}
public class Difference : iCalc
{
public int ReturnResult(int arg1, int arg2)
{
return (arg1 - arg2);
}
}
public class Multiplication : iCalc
{
public int ReturnResult(int arg1, int arg2)
{
return (arg1 * arg2);
}
}
public class Division : iCalc
{
public int ReturnResult(int arg1, int arg2)
{
return Convert.ToInt32(arg1 / arg2);
}
}
Step III - Create a class for factory that contains the method
that will return the product interface
public enum CalculationType
{
Sum,
Difference,
Multiplication,
Division
}
public class Calculator
{
public static iCalc CreateOperation(CalculationType oCalculationType)
{
if (oCalculationType == CalculationType.Sum)
{
return new Sum();
}
else if (oCalculationType == CalculationType.Difference)
{
return new Difference();
}
else if (oCalculationType == CalculationType.Multiplication)
{
return new Multiplication();
}
else if (oCalculationType == CalculationType.Division)
{
return new Division();
}
else
{
throw new ApplicationException("Problem Occurs");
}
}
}
Step IV - Finally use the factory class to get the product
iCalc x = Calculator. CreateOperation(CalculationType.Sum);
int abc = x.ReturnResult(1, 2)