VB.NET Sort Method for a Collection Class

I have a VB.NET collection class EmployeesCollection for an Employee Class that got an Integer Property named Age; I want to create a method (SortByAge) to sort the collection members by Age.

 

This is the EmployeesCollection Class:

 

Imports Microsoft.VisualBasic

Public Class EmployeesCollection
Inherits System.Collections.CollectionBase

Public Sub Add(ByVal tblEmployee As Employee)
' Invokes Add method of the List object to add a widget.
List.Add(tblEmployee)
End Sub

Public ReadOnly Property Item(ByVal index As Integer) As Employee
Get
' The appropriate item is retrieved from the List object and
' explicitly cast to the Widget type, then returned to the
' caller.
Return CType(List.Item(index), Employee)
End Get
End Property

End Class
 

To create the SortByAge method I need a SortHelper Class, This helper Class will include a Function called Compare to compare between the Age values of the employees, the SortHelper Class will be part of the EmployeesCollection Class.

 

 
Private Class AgeSortHelper
        Implements IComparer

        Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer _
             Implements System.Collections.IComparer.Compare
            If x.Age > y. Age Then
                Return 1
            End If

            If x. Age < y. Age Then
                Return -1
            End If

            Return 0
        End Function
    End Class

 

Now we need to create the SortByAge method for the EmployeesCollection Class, in this method we will use the AgeSortHelper to sort the Employees.

 

    Public Sub SortByAge()
        Dim sorter As System.Collections.IComparer = New AgeSortHelper()
        InnerList.Sort(sorter)
    End Sub

 

This is the Final EmployeesCollection Class:

 

Imports Microsoft.VisualBasic

Public Class EmployeesCollection
    Inherits System.Collections.CollectionBase

    Public Sub Add(ByVal tblEmployee As Employee)
        ' Invokes Add method of the List object to add a widget.
        List.Add(tblEmployee)
    End Sub

    Public ReadOnly Property Item(ByVal index As Integer) As Employee
        Get
            ' The appropriate item is retrieved from the List object and
            ' explicitly cast to the Widget type, then returned to the
            ' caller.
            Return CType(List.Item(index), Employee)
        End Get
    End Property

    Public Sub SortByAge()
        Dim sorter As System.Collections.IComparer = New AgeSortHelper()
        InnerList.Sort(sorter)
End Sub
   
Private Class AgeSortHelper
        Implements IComparer

        Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer _
             Implements System.Collections.IComparer.Compare
            If x.Age > y. Age Then
                Return 1
            End If

            If x. Age < y. Age Then
                Return -1
            End If

            Return 0
        End Function

    End Class
End Class


Firefox 2.0 – InnerHTML issue

Sorry about the long time between posts. Hope to start posting again soon

 

Anyhow,

 

I was working on a web application that is updating the details of a <map> HTML element using the innerHTML, the new innerHTML value is being processed in the server side using AJAX function

 

I was using the following JavaScript function to do that

 

function jvUpdateImageMap(ImageMapHTML) 

{

    try

    {

          document.getElementById(“MyImageMap”).innerHTML= ImageMapHTML;

           

     }

catch(err)

          {

          }

          finally

          {

          }

}

 

That was working fine for all the browser including Firefox 3.0 but not for Firefox 2.0

 

After debugging this I found that for FireFox 3.0 the result of updating the InnerHTML is this

 

  <map id=”MyImageMap” >

          <area SHAPE=”rect” id=”0_30″ usemap=”MyImageMap” Border=”0″ href=”#” COORDS=”538,420,550,408″ />

 </map>

 

 

This is the correct expected result

 

But for FIreFox 2.0 the result was this

 

<map id=”MyImageMap” >

<map id=”MyImageMap” >

          <area SHAPE=”rect” id=”0_30″ usemap=”MyImageMap” Border=”0″ href=”#” COORDS=”538,420,550,408″ />

</map>

</map>

 

 

So to fix this I had to add those lines to the server side function that generate the new <map> HTML code  

If Context.Request.Browser.Browser = “Firefox” Then

       If Context.Request.Browser.MajorVersion = “2″ Then

               ImageMapHTML = ImageMapHTML.Replace(“<map id=”"MyImageMap”" >”, “”)

                ImageMapHTML = ImageMapHTML.Replace(“</map>”, “”)

        End If

End If

 

Using PageMethods/WebMethods to update Sessions variable

I created functions for updateing/reading sessions variables using PageMthods and WebMethods, I am using VS2005 (VB.NET):

 

Import the web.services library

  Imports System.Web.Services 

 

This is the VB.NET function for setting the session variables

           <WebMethod()> _

Public Shared Function AjaxSetSession(ByVal SessionValue As String)

                    Try

                             HttpContext.Current.Session(“SessionKey”) = SessionValue

                   Catch ex As Exception

 

                   End Try

          End Function

 To access the session we need to use HttpContext.Current.Session

 

This is the VB.NET function for getting the session variables

       <WebMethod()> _

          Public Shared Function AjaxGetSession() As String

                    Try

                             AjaxGetSession = HttpContext.Current.Session(“SessionKey”)

                    Catch ex As Exception

                             AjaxGetSession = “Error”

                    End Try

    End Function

 

This is the JavaScript Code to set the session variable

 

PageMethods.AjaxSetSession(“PageMethods”,”WebMethods”)

This the JavaScript Code to read the Session Variables

 

PageMethods.AjaxGetSession(JSGetSessionSucess,JSGetSessionFaild);

 

JSGetSessionSucess is a JavaScript function that would be executed if the AjaxGetSession succeeded

 

       function JSGetSessionSucess(value, methodName)

      {

               try

              {

                        alert(value);

                }

catch(err)

               {

               }

               finally

               {

              }

      }

 

JSGetSessionFaild is a JavaScript function that would be executed if the AjaxGetSession failed

        function JSGetSessionFaild (ex, methodName)

      {

               try

              {

                        alert(ex.get_exceptionType());

                }

catch(err)

               {

               }

               finally

               {

              }

      }

 

Handling an Application Event in another application

I was working on a Console application that read SQL Database connection details from a configuration file then send these details to another application (Let us call it the Update Application) which will go through the records of a table to update them using a For Loop, I wanted to show a status message on the Console screen for each record.

 

In the Update Application (VB.NET) I defined a Public event to handle the status message

 

Public Event Message(ByVal sMessage As String)

In the update function I raised this event with the required message

For Each dbRow In DataSet.Tables(“DataTables”).Rows

 

      RaiseEvent Message(“Start Processing record of ID “  & dbRow (“ID”).ToString())

                    ‘Do the Update Here                          

      RaiseEvent Message(“End Processing record of ID “  & dbRow (“ID”).ToString())

 

Next

 

In the Console Application (C#) I defined a handler for the event

 

 

  using System;

  using System.IO;

  public delegate void UpdateAppMessageHandler(string myString);

 

 I defined the required function for the event handler

 

 

   internal class Program

    {

        UpdateAppMessageHandler MySEvent = new UpdateAppMessageHandler (ConsolAppMessageHandler);

 

        static   void  ConsolAppMessageHandler(string sMessage)

        {

            Console.WriteLine(sMessage);

        }

Now I need to assign the Update Application event to the event handler in the Console Application

 

  private static void Main(string[] args)

        {

            try

            {

                UpdateApp MyUpdateApp = null;

                MyUpdateApp = new UpdateApp ();

                MyUpdateApp.Message += ConsolAppMessageHandler; 

                       .

                       .

                       .

Now the Console Screen will show a message for Start/End processing of each record in the Database