Happy Programming

protected void QtyTextBox_TextChanged(object sender, EventArgs e)

ASP.NET maps HTTP requests to HttpHandlers. Each HttpHandler enables processing of individual HTTP URLs or groups of URL extensions within an application. HttpHandlers have the same functionality as ISAPI extensions with a much simpler programming model

Ex
1.Default HttpHandler for all ASP.NET pages ->ASP.NET Page Handler (*.aspx)
2.Default HttpHandler for all ASP.NET service pages->ASP.NET Service Handler (*.asmx)

An HttpHandler can be either synchronous or asynchronous. A synchronous handler does not return until it finishes processing the HTTP request for which it is called.

An asynchronous handler usually launches a process that can be lengthy and returns before that process finishes
After writing and compiling the code to implement an HttpHandler you must register the handler using your application's Web.config file.

Caching is a technique of persisting the data in memory for immediate access to requesting program calls. This is considered as the best way to enhance the performance of the application.

Caching is of 3 types:
Output Caching - Caches the whole page.
Fragment Caching - Caches a part of the page
Data Caching - Caches the data

Multilingual website can be created using Globalization and Localization.

Using Globalization we change the Currency Date Numbers etc to Language Specific Format.

To change the string which is there in the label button etc to language specific string we use Localization.

In Localization we have to create different Resource files for different languages.

During this process we use some classes present in System.Resources/ System.Globalization System.Threading namespaces.

Coming to Session State
As we know for every process some default space will be allocated by OS.

In case of InProc Session Info will be stored inside the process where our
application is running.
In case of StateServer Session Info will be stored using ASP.NET State Service.
In case of SQLServer Session info will be stored inside Database. Default DB
which will be created after running InstallSQLState Script is ASPState.

Session Management can be achieved in two ways

1)InProc
2)OutProc

OutProc is again two types
1)State Server
2)SQL Server

InProc
Adv.:
1) Faster as session resides in the same process as the application
2) No need to serialize the data

DisAdv.:
1) Will degrade the performance of the application if large chunk of data is stored
2) On restart of IIS all the Session info will be lost

State Server
Adv.:
1) Faster then SQL Server session management
2) Safer then InProc. As IIS restart
won't effect the session data

DisAdv.:
1) Data need to be serialized
2) On restart of ASP.NET State Service session info will be lost
3)Slower as compared to InProc

SQL Server
Adv.:
1) Reliable and Durable
2) IIS and ASP.NET State Service
restart won't effect the session data
3) Good place for storing large chunk of data

DisAdv.:
1) Data need to be serialized
2) Slower as compare to InProc and State Server
3)Need to purchase Licensed
version of SQL Serve

Customer foundCustomer = null;
foundCustomer = custList.FirstOrDefault(c =>
c.CustomerId == 4);
Debug.WriteLine(foundCustomer);

The lambda expression syntax in C# looks like this:

c => c.CustomerId == 4

The code begins with the set of parameters to the lambda expression. The => is the “goes to” or lambda operator. The remainder of the code is the expression itself. In this case, checking for the item in the list where CustomerId is 4.

2)...

Customer foundCustomer = null;
var query = from c in custList
where c.CustomerId == 4
select c;
foundCustomer = query.FirstOrDefault();
Debug.WriteLine(foundCustomer);

3)...

Customer foundCustomer = null;
foreach (var c in custList)
{
if (c.CustomerId == 4)
{
foundCustomer = c;
break;
}
}
Debug.WriteLine(foundCustomer);

Regex syntax is :

Regex re = new Regex("Regular Expression string",Regular Expression Options);

Regular Expression Options are options that we can use along with regular expression like RegexOptions.IgnoreCase or RegexOptions.Compiled

Here I am lisitng some Regular Expressions:

[a-zA-Z]* - Regular Expression to allow only charactors

[0-9]* - Regular Expression to allow only numbers

[a-zA-Z0-9]* - Regular Expression to allow only alphanumeric charactors

[0-9]*(\.[0-9]{1,2})? - Regular Expression to validate a float number with 1 or 2 decimal points

XAML itself is a larger language concept than WPF.

Creational Patterns
Abstract Factory	Creates an instance of several families of classes
Builder	Separates object construction from its representation
Factory Method	Creates an instance of several derived classes
Prototype	A fully initialized instance to be copied or cloned
Singleton	A class of which only a single instance can exist

Structural Patterns
Adapter	Match interfaces of different classes
Bridge	Separates an object’s interface from its implementation
Composite	A tree structure of simple and composite objects
Decorator	Add responsibilities to objects dynamically
Facade	A single class that represents an entire subsystem
Flyweight	A fine-grained instance used for efficient sharing
Proxy	An object representing another object

Behavioral Patterns
Chain of Resp.	A way of passing a request between a chain of objects
Command	Encapsulate a command request as an object
Interpreter	A way to include language elements in a program
Iterator	Sequentially access the elements of a collection
Mediator	Defines simplified communication between classes
Memento	Capture and restore an object's internal state
Observer	A way of notifying change to a number of classes
State	Alter an object's behavior when its state changes
Strategy	Encapsulates an algorithm inside a class
Template Method	Defer the exact steps of an algorithm to a subclass
Visitor	Defines a new operation to a class without change

What is FILESTREAM?

FILESTREAM is a new feature introduced in SQL Server 2008 which provides an efficient storage and management option for BLOB data.

Many applications that deal with BLOB data today stores them in the file system and stores the path to the file in the relational tables. Storing BLOB data in the file system is more efficient that storing them in the database. However, this brings up a few disadvantages as well. When the BLOB data is stored in the file system, it is hard to ensure transactional consistency between the file system data and relational data.

Some applications store the BLOB data within the database to overcome the limitations mentioned earlier. This approach ensures transactional consistency between the relational data and BLOB data, but is very bad in terms of performance.

FILESTREAM combines the benefits of both approaches mentioned above without the disadvantages we examined. FILESTREAM stores the BLOB data in the file system (thus takes advantage of the IO Streaming capabilities of NTFS) and ensures transactional consistency between the BLOB data in the file system and the relational data in the database.

There are three basic classification of patterns Creational, Structural, Behavioral patterns.

use Northwind

declare @CategoryList varchar(1000)
select @CategoryList = coalesce(@CategoryList + ‘, ‘, ”) + CategoryName from Categories

select ‘Results = ‘ + @CategoryList

Ex :

BatchExeProduct batchExeProductObject = batchExeProducts.Find(delegate(BatchExeProduct ep) {return ep.ExecutiveCode == exeCode; });

So far I've tried the page directive:

@ OutputCache Duration="1" Location="None"

The Meta tags:

<meta http-equiv="Expires" CONTENT="0">

<meta http-equiv="Cache-Control" CONTENT="no-cache">

<meta http-equiv="Pragma" CONTENT="no-cache">

And the code:

Response.ExpiresAbsolute = DateTime.Now

Response.Expires = -1441

Response.CacheControl = "no-cache"

Response.AddHeader("Pragma", "no-cache")

Response.AddHeader("Pragma", "no-store")

Response.AddHeader("cache-control", "no-cache")

Response.Cache.SetCacheability(HttpCacheability.NoCache)

Response.Cache.SetNoServerCaching()

WHERE convert (datetime, convert (varchar, datecol, 101), 101) = @yourdate