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 id="Head1" 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:


1.png

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


2.png


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


3.png


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



4.png


I hope this article is useful for you. I look forward to your comments and feedback.