ASP.Net User Controls


User controls are containers into which you can put markup and Web server controls. You can then treat the user control as a unit and define properties and methods for it. User controls are substantially easier to create than custom controls, because you can reuse existing controls. They make it particularly easy to create controls with complex user interface elements.
Heilights of user control;

  • .ascx files
  • Use of @Control directive instead of @Page
  • Cannot be run as a stand alone application, requires an aspx page
  • No html tags like html, body, form. Other tags are allowed

Steps to create user control;

  1. Create a web application from Visual studio
  2. Select project from solution explorer -> right click, Add new item -> Web User control
  3. Add controls and related events
  4. Add an aspx page to the project
  5. Make use of @Register directive to use created user control
Example:

Page Design -

Page header -

Server script -



Hello World of LINQ

LINQ (Language Integrated Query) is an expression language used to retrieve data from data source. This data source can be a SQL data provider or XML file. LINQ is mainly developed to overcome an extra overhead of learning so many query languages. There are lot of query languages available as of now and they are changing day by day. Developers have to learn each of them based on application needs.
LINQ plays a vital role in this. It is a generalized query language which can be used with various kinds of data sources and formats.
Here is a simple program which demonstrates LINQ functioning.

The query doesn't work by specifying the query variable itself.  "foreach" loop refers to the query variable and then the logic written in query is executed. Then developer can process on fetched data in the loop. Hers is how the LINQ works.


Please see the bottom section of page for references.

How to read data from console ?

One of my friend asked me this question today morning and I was bit surprised. I mixed up things saying it must be something like scanf statements. Then I searched it and figured out the steps to do so.


In this code, Console.ReadLine() will accept an input from the keyboard and it will store it in specified variable. Here I wanted to read an integer value from keyboard, so I used Console.Read() first. Console.Read() accepts one character at a time. So it is of new use for accepting integer value. Int32.TryParse() function accepts the value and tries to convert it to integer. This function returns boolean value as success or failure.