Introduction

Today, in this article let's play around with one of the interesting and most useful concepts of design patterns, which will be hosted in a web app.

Question: What is a Factory Pattern ?

In simple terms "Creates an object without exposing implementation logic to the client".
I think we are now good to go to implement this wonderful concept.

Step 1: The complete code of Default.aspx looks like this:


<
%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="FactoryPatternApplication._Default" %>

<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">

<title></title>

</head>

<body>

<form id="form1" runat="server">

<div>

<h1 style="text-align:center; font-family:Verdana; font-size:large; color:Maroon">Factory Pattern - Design Patterns</h1>

<center>

<table>

<tr>

<td>

<asp:Label ID="Label1" runat="server" Text="Please Enter First Number" Font-Size="Small" Font-Bold="true" Font-Italic="true" Font-Names="Verdana"></asp:Label>

</td>

<td>

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td>

<asp:Label ID="Label2" runat="server" Text="Please Enter Second Number" Font-Size="Small" Font-Bold="true" Font-Italic="true" Font-Names="Verdana"></asp:Label>

</td>

<td>

<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td colspan="2">

<asp:Button ID="Button1" runat="server" Text="Addition" Width="165px"Font-Names="Verdana" BackColor="Orange" onclick="Button1_Click" />

</td>

</tr>

<tr>

<td colspan="2">

<asp:Button ID="Button2" runat="server" Text="Subtraction" Width="165px"Font-Names="Verdana" BackColor="Orange" onclick="Button2_Click" />

</td>

</tr>

<tr>

<td colspan="2">

<asp:Button ID="Button3" runat="server" Text="Multiplication" Width="165px"Font-Names="Verdana" BackColor="Orange" onclick="Button3_Click" />

</td>

</tr>

<tr>

<td colspan="2">

<asp:Button ID="Button4" runat="server" Text="Division" Width="165px"Font-Names="Verdana" BackColor="Orange" onclick="Button4_Click" />

</td>

</tr>

</table>

<table>

<tr>

<td colspan="2">

<asp:Label ID="lblResult" runat="server" Font-Names="Verdana" ForeColor="Brown"></asp:Label>

</td>

</tr>

</table>

</center>

</div>

</form>

</body>

</html>


Step 2: The complete code of IAdd.cs looks like this:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace FactoryPatternApplication

{

public interface IAdd

{

double Add(double a, double b);

}

}

Step 3: The complete code of ISub.cs looks like this:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace FactoryPatternApplication

{

public interface ISub

{

double Sub(double a, double b);

}

}

Step 4: The complete code of IMul.cs looks like this:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace FactoryPatternApplication

{

public interface IMul

{

double Mul(double a, double b);

}

}


Step 5: The complete code of IDiv.cs looks like this:


using
System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace FactoryPatternApplication

{

public interface IDiv

{

double Div(double a, double b);

}

}


Step 6: The complete code of Addition.cs looks like this:


using
System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace FactoryPatternApplication

{

public class AdditionClass : IAdd

{

public double Add(double a, double b)

{

return a + b;

}

}

}

Step 7: The complete code of Subtraction.cs looks like this:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace FactoryPatternApplication

{

public class SubtractionClass : ISub

{

public double Sub(double a, double b)

{

return a - b;

}

}

}

Step 8: The complete code of Multiplication.cs looks like this:


using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace FactoryPatternApplication

{

public class MultiplicationClass : IMul

{

public double Mul(double a, double b)

{

return a * b;

}

}

}

Step 9: The complete code of Division.cs looks like this:


using
System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace FactoryPatternApplication

{

public class DivisionClass : IDiv

{

public double Div(double a, double b)

{

return a / b;

}

}

}

Step 10: The complete code of ArthmeticFactory.cs looks like this:


using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI.WebControls;

namespace FactoryPatternApplication

{

public class ArthmeticFactory

{

public IAdd getAdd(string a)

{

if (a == "Addition"){return new AdditionClass();

}

elsereturn null;

}

public ISub getSub(string a)

{

if (a == "Subtraction")

{

return new SubtractionClass();

}

elsereturn null;

}

public IMul getMul(string a){if (a == "Multiplication")

{

return new MultiplicationClass();

}

elsereturn null;

}

public IDiv getDiv(string a)

{

if (a == "Division")

{

return new DivisionClass();

}

elsereturn null;

}

}

}

Step 11: The complete code of Default.aspx.cs looks like this:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;namespace FactoryPatternApplication

{
public
partial class _Default : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e){}

protected void Button1_Click(object sender, EventArgs e)

{

if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text))

{

lblResult.Text = "Please Enter Some Values";

}

else

{

var a = Button1.Text;IAdd obj_Add = objFactory.getAdd(a);

lblResult.Text = "Addition Result of " + TextBox1.Text + " and " + TextBox2.Text + " is : <b>" + obj_Add.Add

(Convert.ToDouble(TextBox1.Text), Convert.ToDouble(TextBox2.Text)) + "</b>";TextBox1.Text = "";

TextBox2.Text = "";}}protected void Button2_Click(object sender, EventArgs e)

{

if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text))

{

lblResult.Text = "Please Enter Some Values";

}

else

{

var a = Button2.Text;ISub obj_Sub = objFactory.getSub(a);

lblResult.Text = "Subtraction Result of " + TextBox1.Text + " and " + TextBox2.Text + " is : <b>" +

obj_Sub.Sub(Convert.ToDouble(TextBox1.Text),

Convert.ToDouble(TextBox2.Text)) + "</b>";TextBox1.Text = "";

TextBox2.Text = "";

}

}

protected void Button3_Click(object sender, EventArgs e)

{

if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text))

{

lblResult.Text = "Please Enter Some Values";

}

else

{

var a = Button3.Text;IMul obj_Mul = objFactory.getMul(a);

lblResult.Text = "Multiplication Result of " + TextBox1.Text + " and " + TextBox2.Text + " is : <b>" + obj_Mul.Mul

(Convert.ToDouble(TextBox1.Text),

Convert.ToDouble(TextBox2.Text)) + "</b>";TextBox1.Text = "";TextBox2.Text = "";

}

}

protected void Button4_Click(object sender, EventArgs e)

{

if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text))

{

lblResult.Text = "Please Enter Some Values";

}

else

{

var a = Button4.Text;IDiv obj_Div = objFactory.getDiv(a);lblResult.Text = "Division Result of " +

TextBox1.Text + " and " + TextBox2.Text + " is : <b>" + obj_Div.Div

(Convert.ToDouble(TextBox1.Text),

Convert.ToDouble(TextBox2.Text)) + "</b>";TextBox1.Text = "";TextBox2.Text = "";

}

}

#region Instance MembersArthmeticFactory objFactory = new ArthmeticFactory();#endregion

}

}

Step 12: The output of the application looks like this:

Output1.png

Step 13: The output of the nothing entered application looks like this:

Output2.png


Step 14: The output of the addition operation application looks like this:


Output3.png

Step 15: The output of the division operation application looks like this:

Output4.png