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 Adapter Pattern?

In simple terms "When working with incompatible interfaces, an adapter pattern helps to synchronize and make the classes compatible among each other".

I think we are now good to go and 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="AdapterDesignPatternApp.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">

Adapter 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="Button1Click" />

</td>

</tr>

<tr>

<td colspan="2">

<asp:Button ID="Button2" runat="server" Text="Subtraction" Width="165px" Font-Names="Verdana"

BackColor="Orange" OnClick="Button2Click" />

</td>

</tr>

<tr>

<td colspan="2">

<asp:Button ID="Button3" runat="server" Text="Multiplication" Width="165px" Font-Names="Verdana"

BackColor="Orange" OnClick="Button3Click" />

</td>

</tr>

<tr>

<td colspan="2">

<asp:Button ID="Button4" runat="server" Text="Division" Width="165px" Font-Names="Verdana"

BackColor="Orange" OnClick="Button4Click" />

</td>

</tr>

</table>

<table>

<tr>

<td colspan="2">

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

{

public interface IAdd { void Add();}

}

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

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace AdapterDesignPatternApp

{

public interface ISub { void Sub();}

}

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

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace AdapterDesignPatternApp

{

public interface IMul { void Mul();}

}

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


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace AdapterDesignPatternApp
{
public interface IDiv { void Div();}
}

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


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace AdapterDesignPatternApp
{
public class MyAddition { public double Addition(double a, double b) { return a + b; } }
}

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


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace AdapterDesignPatternApp
{
public class MySubtraction { public double Subtraction(double a, double b) { return a - b; } }
}

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

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace AdapterDesignPatternApp

{

public class MyMultiplication { public double Multiplication(double a, double b) { return a * b; } }

}

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

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace AdapterDesignPatternApp

{

public class MyDivision { public double Division(double a, double b) { return a / b; } }

}

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

using System;

using System.Globalization;

namespace AdapterDesignPatternApp

{

public partial class Default : System.Web.UI.Page, IAdd, ISub, IMul, IDiv

{

protected void Page_Load(object sender, EventArgs e){TextBox1.Focus();

}

protected void Button1Click(object sender, EventArgs e){Add();

}

protected void Button2Click(object sender, EventArgs e){Sub();

}

protected void Button3Click(object sender, EventArgs e){Mul();

}

protected void Button4Click(object sender, EventArgs e){Div();

}

public void Add()

{

if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text)){lblResult.Text = "Please Enter Some Values";

lblResult.ForeColor = System.Drawing.Color.Red;

{

lblResult.Text = "Addition Result is: <b>"+TextBox1.Text+"</b>"+" and "+TextBox2.Text+" is <b>"+_objAddition.Addition(Convert.ToDouble(TextBox1.Text), Convert.ToDouble(TextBox2.Text)).ToString(CultureInfo.InvariantCulture)+"</b>";

lblResult.ForeColor = System.Drawing.Color.Green;TextBox1.Text = "";TextBox2.Text = "";

}

}

public void Sub()

{

if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text)){lblResult.Text = "Please Enter Some Values";

lblResult.ForeColor = System.Drawing.Color.Red;

}

else

{

lblResult.Text = "Subtraction Result is: <b>" + TextBox1.Text + "</b>" + " and " + TextBox2.Text + " is <b>" + _objSubtraction.Subtraction(Convert.ToDouble(TextBox1.Text), Convert.ToDouble(TextBox2.Text)).ToString(CultureInfo.InvariantCulture) + "</b>";lblResult.ForeColor = System.Drawing.Color.Green;TextBox1.Text = "";

TextBox2.Text = "";

}

}

public void Mul()

{

if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text)){lblResult.Text = "Please Enter Some Values";

lblResult.ForeColor = System.Drawing.Color.Red;

}

else{lblResult.Text = "Multiplication Result is: <b>" + TextBox1.Text + "</b>" + " and " + TextBox2.Text + " is <b>" + _objMultiplication.Multiplication(Convert.ToDouble(TextBox1.Text), Convert.ToDouble(TextBox2.Text)).ToString(CultureInfo.InvariantCulture) + "</b>";

lblResult.ForeColor = System.Drawing.Color.Green;TextBox1.Text = "";TextBox2.Text = "";

}

}public void Div()

{

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

{

lblResult.Text = "Please Enter Some Values";

lblResult.ForeColor = System.Drawing.Color.Red;

}

else

{

lblResult.Text = "Division Result is: <b>" + TextBox1.Text + "</b>" + " and " + TextBox2.Text + " is <b>" + _objDivision.Division(Convert.ToDouble(TextBox1.Text), Convert.ToDouble(TextBox2.Text)).ToString(CultureInfo.InvariantCulture) + "</b>";

lblResult.ForeColor = System.Drawing.Color.Green;

TextBox1.Text = "";TextBox2.Text = "";

}

}

#region Private Instance Variablesprivate readonly MyAddition _objAddition = new MyAddition();

private readonly MySubtraction _objSubtraction = new MySubtraction();

private readonly MyMultiplication _objMultiplication = new MyMultiplication();

private readonly MyDivision _objDivision = new MyDivision();#endregion

}

Step 11: The output of the application looks like this:


Output1.png


Step 12: The output of the nothing entered application looks like this:


Output2.png

Step 13: The output of the addition operation application looks like this:


Output3.png

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

Output4.png

I hope this article is useful for you.