What are events in GLOBAL.ASAX file?

The Global.asax file, which is derived from the HttpApplication class, maintains a pool of HttpApplication objects, and assigns them to applications as needed. The Global.asax file contains the following events:

Application_Init: Fired when an application initializes or is first called. It is invoked for all HttpApplication object instances.

Application_Disposed: Fired just before an application is destroyed. This is the ideal location for cleaning up previously used resources.

Application_Error: Fired when an unhandled exception is encountered within the application.

Application_Start: Fired when the first instance of the HttpApplication class is created. It allows you to create objects that are accessible by all HttpApplication instances.

Application_End: Fired when the last instance of an HttpApplication class is destroyed. It is fired only once during an application's lifetime.

Application_BeginRequest: Fired when an application request is received. It is the first event fired for a request, which is often a page request (URL) that a user enters.

Application_EndRequest: The last event fired for an application request.

Application_PreRequestHandlerExecute: Fired before the ASP.NET page framework begins executing an event handler like a page or Web service.

Application_PostRequestHandlerExecute: Fired when the ASP.NET page framework has finished executing an event handler.

Applcation_PreSendRequestHeaders: Fired before the ASP.NET page framework sends HTTP headers to a requesting client (browser).

Application_PreSendContent: Fired before the ASP.NET page framework send content to a requesting client (browser).

Application_AcquireRequestState: Fired when the ASP.NET page framework gets the current state (Session state) related to the current request.

Application_ReleaseRequestState: Fired when the ASP.NET page framework completes execution of all event handlers. This results in all state modules to save their current state data.

Application_ResolveRequestCache: Fired when the ASP.NET page framework completes an authorization request. It allows caching modules to serve the request from the cache, thus bypassing handler execution.

Application_UpdateRequestCache: Fired when the ASP.NET page framework completes handler execution to allow caching modules to store responses to be used to handle subsequent requests.

Application_AuthenticateRequest: Fired when the security module has established the current user's identity as valid. At this point, the user's credentials have been validated.

Application_AuthorizeRequest: Fired when the security module has verified that a user can access resources.

Session_Start: Fired when a new user visits the application Web site.

Session_End: Fired when a user's session times out, ends, or they leave the application Web site.

Difference between ASP and ASP.Net

ASP session state is dependent on IIS process very heavily. So if IIS restarts ASP session variables are also recycled	ASP.NET session can be independent of the hosting environment thus ASP.NET session can maintained even if IIS reboots.
ASP session only works when browser supports cookies	ASP.NET session can be used with browser side cookies or independent of it.
ASP session state has no inherent solution to work with Web Farms	ASP.NET session can be stored in state server and SQL SERVER which can support multiple servers.
ASP is interpreated	ASP.Net is complied
ASP uses ADO	ASP.Net uses ADO.Net
ASP, there was no server controls. You have to write all html tags manually	ASP.NET offers a very rich set of controls called Server Controls and Html Controls. It is very easy to drag and drop any controls to a web form
ASP uses vb script for server side coding. Vb Script is not supported any more in ASP.NET	nstead, ASP.NET supports more languages including C#, VB.NET, J# etc.
ASP did not support Page level transactions	SP.NET supports Page level transactions
ASP does not offer support for Web Services and rich data structures like DataSet which allows disconnected data processing.	ASP.NET offers support for Web Services and rich data structures like DataSet which allows disconnected data processing.
ASP had maximum of 4 built in classes like Request, Response, Session and Application	ASP.NET using .NET framework classes which has more than 2000 in built classes
ASP has Mixed HTML and coding logic	Separate code and design logic possible
Limited development and debugging tools available	Variety of compilers and tools available including the Visual studio.Net
No in-built support for XML	Full XML Support for easy data exchange
No fully distributed data source support.	Fully distributed data source support
Poor Error handling system	Full proof error handling possible
Limited OOPS support	Completely Object Oriented.

How to freeze Gridview columns in ASP.net?

I am writing below blog from one of my last project experience. I was doing a project called timesheet where i was in need of showing lots of details of the user whose timesheet is been submitted. For Example: Name, DOB, Department, Type, Designation and all the 30/31 days of the months.

Since it became difficult to show all the information in gridview becuase there is no built in functionality of scrolling. So I thought of freezing some of the columns of the gridview and keeping all other columns as it is.

I used CSS to handle this.

Find below the html:

<style type="text/css">

.Container

{

overflow: auto;

}

.FreezeCell

{

background-color:#d9e9ff;

position: relative;

font-family:Segoe UI;

font-size:11px;

font-weight:normal;

cursor: auto;

left: expression(document.getElementById("GridView1").scrollLeft-1);

}

.FreezeHeader

{

background-color:#d9e9ff;

font-weight:normal;

font-family:Segoe UI;

font-size:11px;

position: relative;

cursor: auto;

top: expression(document.getElementById("GridView1").scrollTop-1);

z-index: 10;

}

.FreezeHeader.locked

{

z-index: 99;

}

style>

<div id="div1" class="Container" style="width: 200px; color: #4977bc;

border-style: solid; border-width: thin;" runat="server">

<asp:GridView ID="GridView1" CssClass="GridView" runat="server" Width="250px"

GridLines="Both" BorderWidth="1px" AutoGenerateColumns="false">

<HeaderStyle BackColor="#d9e9ff" Font-Bold="false" Font-Names="Segoe UI" Font-Size="11px" />

<Columns>

<asp:BoundField DataField="name" HeaderText="Name" HeaderStyle-Width="100px" ItemStyle-CssClass="FreezeCell"

HeaderStyle-CssClass="FreezeCell">

<ItemStyle VerticalAlign="Top" BackColor="#ffffff" Width="100px"/>

asp:BoundField>

<asp:BoundField DataField="age" HeaderText="Age" HeaderStyle-Width="50px" >

<ItemStyle VerticalAlign="Top" Width="50px" HorizontalAlign="center" BackColor="#ffffff" />

asp:BoundField>

<asp:BoundField DataField="sex" HeaderText="Sex" HeaderStyle-Width="50px"

HeaderStyle-HorizontalAlign="left">

<ItemStyle VerticalAlign="Top" Width="50px" HorizontalAlign="left" BackColor="#ffffff" />

asp:BoundField>

<asp:BoundField DataField="datetime" HeaderText="DateTime" HeaderStyle-Width="15px"

HeaderStyle-HorizontalAlign="left">

<ItemStyle VerticalAlign="Top" Width="150px" HorizontalAlign="left" BackColor="#ffffff" />

asp:BoundField>

Columns>

asp:GridView>

div>

C# Source Code:

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Collections.Generic;

public class PersonInfo

{

private string name;

public string Name

{

get { return name; }

set { name = value; }

}

private string age;

public string Age

{

get { return age; }

set { age = value; }

}

private string sex;

public string Sex

{

get { return sex; }

set { sex = value; }

}

private DateTime datetime;

public DateTime DateTime

{

get { return datetime; }

set { datetime = value; }

}

}

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

{

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

List<PersonInfo> listPersonInfo = new List<PersonInfo>();

for (int i = 0; i <>

{

PersonInfo p = new PersonInfo();

p.Name = "Ashraf" + i.ToString();

p.Age = "23" + i.ToString();

p.Sex = "Male";

p.DateTime = DateTime.Now;

listPersonInfo.Add(p);

}

GridView1.DataSource = listPersonInfo;

GridView1.DataBind();

}

}

}

This works perfectly for me.

How to open a dll file?

Recently I was working for a Tool and I was bit familiar and sure that existing dll files can be open to view their source code. I knew there are some tools which help you to do that.

Note: This is only possible if dll not obfuscated.

Obfuscation: It is a process that makes it difficult to reengineer the code. Obfuscating is a way to hide your assembly or EXE code from reflection.

Obfuscation simple meaning is making something difficult to read, understand and interpret. Obfuscation leads to doing something intentionally ambogious and confusing.

The same applies to .Net dll files. We know that .Net assemblies can be open to know what inside using reflector tools provided. So it is the need of individuals or personnel to protect their work that nobody copies or understand.The obfuscation alogorthims may use one of the following approaches.

• Changing the variables, functions and method name.
• Using Encoding
• Using encyrption and dycryption techniques.

I will demonstrate this proces using a tool Red Gat’s .Net Reflector.You can download from here: http://www.red-gate.com/products/reflector/

Step1: Run the tool

Go to File->Open-> Browse the dll file to open. Here I have selected PM.dll file

Step2: Explore your methods, classes, properties to see the code

There are many tools availble like .Net Reflector 2.4 etc. You can download to look into your dll files.

I hope you enjoyed this, but at the same time you should also understand how can you protect your dll not to be open by anyone else if they values.