A New Approach To .NET Key Value pairs in Collections

A new approach has been evolved in the Collections ,i.e The LookUp is one the Class in the Collection which represents a collection of keys each mapped to one or more values.

We are very familiar with the Dictonary Collection which maps only one value per key mapping.But when we come across to map the keys with more values.Then we have this LookUp
Where
TKey    ----> The types of the keys in the LookUp
TValue ---->    The type of the elements of each IEnumerable value in the LookUp.

I have worked out on this concept to understand the LookUp class. Before going in deeply , let's create a Custom Class like this
Employee.cs
using System.Collections.Generic;

///
/// Summary description for Employee
///
public class Employee
{
    public int ID { get; set; }
    public string Email { get; set; }
    public int Age { get; set; }
    public string Name { get; set; }
    public bool MartialStatus { get; set; }
    public Employee()
    {
         //
        // TODO: Add constructor logic here
        //
    }
  }
I have taken an aspx page which i have designed like this:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="LookUpDemo.aspx.cs" Inherits="LookUpDemo" %>


<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Demo on Lookup(TKey,TElement) Classtitle>
    <style type="text/css">
        .rbn
        {
            font-family: Verdana;
            font-size: small;
        }
     style>
head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="gv1" runat="server" BackColor="White" BorderColor="#CC9966" BorderStyle="None"
             BorderWidth="1px" CellPadding="4">
            <FooterStyle BackColor="#FFFFCC" ForeColor="#330099" />
            <HeaderStyle BackColor="#990000" Font-Bold="True" ForeColor="#FFFFCC" />
            <PagerStyle BackColor="#FFFFCC" ForeColor="#330099" HorizontalAlign="Center" />
            <RowStyle BackColor="White" ForeColor="#330099" />
            <SelectedRowStyle BackColor="#FFCC66" Font-Bold="True" ForeColor="#663399" />
            <SortedAscendingCellStyle BackColor="#FEFCEB" />
            <SortedAscendingHeaderStyle BackColor="#AF0101" />
            <SortedDescendingCellStyle BackColor="#F6F0C0" />
            <SortedDescendingHeaderStyle BackColor="#7E0000" />
        asp:GridView>
        <div class="rbn">
            <label for="rbnList" style="font-weight: bold">
                Select the Martial Status(Checked Checkboxes are Married)label>
            <asp:RadioButtonList ID="rbnList" runat="server" AutoPostBack="true" OnSelectedIndexChanged="rbnList_SelectedIndexChanged">
                 <asp:ListItem Text="Single" Value="false">asp:ListItem>
                 <asp:ListItem Text="Married" Value="true">asp:ListItem>
            asp:RadioButtonList>
        div>
        <br />
        <asp:GridView ID="gv2" runat="server" CellPadding="4" ForeColor="#333333" GridLines="None">
            <AlternatingRowStyle BackColor="White" />
            <EditRowStyle BackColor="#2461BF" />
            <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
            <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
            <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
            <RowStyle BackColor="#EFF3FB" />
            <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
            <SortedAscendingCellStyle BackColor="#F5F7FB" />
            <SortedAscendingHeaderStyle BackColor="#6D95E1" />
            <SortedDescendingCellStyle BackColor="#E9EBEF" />
            <SortedDescendingHeaderStyle BackColor="#4870BE" />
        asp:GridView>
    div>
    form>
body>
html>

Here in my example i have taken the Employee Details and i am showing the employee details in the first grid.Below that i have taken a radiobutton list which has two ListItems Called "SINGLE" and "MARRIED".

These ListItems "SINGLE" and "MARRIED" have values as "false" and "true".  The LookUp has keys each mapped to the one or more values.So based on the key selected the values will be filtered and showed in the below gridview.

"Now, before defining a Lookup Collection, we need to know some basic fundamentals . Like Dictionary we can not create a Lookup Collection directly. While creating the instance of the  Lookup collection object, we need to invoke an extension method called ToLookup()  which will be returning a Lookup object. "

The following code snippet shows creation of a Lookup Collection with key type of Boolean with Employee Collection.image
View Image

empList.ToLookup(c => c.MartialStatus) will  pass  LookupEmployee>  to employeeLookup Collection. The Lookup collection is created on key type of Boolean. Hence we can access the elements as follows,
The demo can be downloaded from here.  DOWNLOAD.


 

Comments

Post a Comment

Popular posts from this blog

Exporting to excel from a custom class object using C#.NET

We may face a scenario to export the data of custom class object to excel using InterOp .You can get the property name's from the class object using Reflection.Create a work sheet header by reading the each propety of the class object.I have created a separate method to get the all properties into a list collection of string as given below         ///         /// Get the list of Properties Name into a list collection.         ///         ///         ///         public List GetPropeties(Employee objEmployee)         {             Type myType = objEmployee.GetType();             IList props = new List (myType.GetProperties());             List lstPropertiesNames = new List ();             foreach (PropertyInfo prop in props)             {                 lstPropertiesNames.Add(prop.Name);             }             return lstPropertiesNames;         } We need to call this method to create the worksheet header's as given beloe                 List lstProperties = GetPropet
Read more

Why Dispose() is preferred than Finalize() for Un-Managed Resources in .NET?

Image
Memory management is very important in any application development.The Garbage collector of .NET does almost all clean up activity for your objects.For unmanaged resources (Ex:Windows API created objects, File, Database connection objects, COM objects, etc.) are outside the scope of .NET framework. Why Dispose() is preferred than Finalize() If we use the " Finalize() " method,the  Garbage collector has to make two round in order to remove the objects. For an instance ,let me explain clearly if we have two objects as Object1 and Object2 and we finalize the Object2 as given in the below image.The GC has to categorize the two objects and put the Finalize objects into Finalization Queue.The GC will clean the object1 which doesn't use the Finalize() method and process the second round of cleaning the Finalization Queue. Now at this the " Dispose() " method will come into picture.This method belongs to IDisposable() interface .So the best practise to rele
Read more

How to apply watermark to the textbox and dropdownlist?

Create a watermark effect on your TextBox and display instructions to users, without taking up screen space.This warkmark style can applied by using the CSS and append this to your control using jquery. Hi this is basic where we you use to get to apply watermark to the Textbox or DropDown.I have implemented this by using the jquery. <%@ Page Language="C#" AutoEventWireup="true" CodeFile="WaterMark.aspx.cs" Inherits="WaterMark" %> < html xmlns ="http://www.w3.org/1999/xhtml"> < head runat ="server">      < title > Water Mark using jquery title >      < style type ="text/css">         .watermarkOn         {             color: #CCCCCC;             font-style: italic;         }       style >      < script type ="text/javascript" src ="http://code.jquery.com/jquery-1.4.1.js"> script >      < script ty
Read more