DOT NET – What is a cookie

Recently I got a message from one of the reader of my site that what exactly is a cookie. So I decided to wire a post dedicated to it .

  1. A cookie is name=value pair like variable which is stored as a file(persistant cookie) and which travels automatically between every request and response.
  2. Cookies are based on domains(website). As long as user is working with current web site cookie will be available.
  3. Cookies are maintained by browser but not by server which means cookies based websites are dependent on client.
  4. Cookies can be created as
    (i) In-memory cookie
    (ii) Persistant Cookie

An In-memory cookie means as long as user is working with app it will be available – also called as Session Cookie.

Persistant cookie means it will be stored in client physical location and available online as well as offline.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

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C Sharp (programming language) and History

C# is an object-oriented programming language developed by Microsoft as part of the .NET initiative and later approved as a standard by ECMA and ISO . Anders Hejlsberg leads development of the C# language, which has a procedural, object-oriented syntax based on C++ and includes influences from aspects of several other programming languages (most notably Delphi and Java) with a particular emphasis on simplification.

History

During the development of .NET, the class libraries were originally written in a language called Simple Managed C (SMC). In January 1999, Anders Hejlsberg formed a team to build a new language at the time called Cool. By the time the .NET project was publicly announced at the July 2000 Professional Developers Conference (PDC), the language had been renamed C# and the class libraries and ASP.NET runtime had been ported to C#.

C#’s principal designer and lead architect at Microsoft is Anders Hejlsberg, who was previously involved with the design of Visual J++, Borland Delphi, and Turbo Pascal. In interviews and technical papers he has stated that flaws in most major programming languages (e.g. C++, Java, Delphi, and Smalltalk) drove the fundamentals of the Common Language Runtime (CLR), which, in turn, drove the design of the C# programming language itself.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

CSS NAVIGATION BAR

Many a time when there is a need to go for a navigation bar we simply remember javascript and write a functionality based on mouse onhouver property, we achieve the functionality but sometimes when javascript is disabled on clients computer then what the function never fires but in CSS we have functionality called hover will always run independent of javascript and writing is also very simple here is example how we can achieve it.

Step 1: Create an html file copy and paste the code below.

xmlns=”http://www.w3.org/1999/xhtml”>

<head>

<meta http-equiv=”Content-Type” content=”text/html; charset=iso-8859-1″ />

<title>Strip Menu Model</title>

<style type=”text/css”>

.stripboxmenu {padding: 0; width: 100%; /* width of the menu strip, 100% will extend to the full resolution of the screen */

border-top: 5px solid #000033; /*specify the color strip width,color */

background: transparent;

}

.stripboxmenu ul {margin:0;

margin-left: 80px; /*space between first menu item and left edge*/

padding: 0; /*Spacing between the strip and menu boxes*/

list-style: none;

}

.stripboxmenu li {display: inline;

margin: 2 2px 2 2;

padding: 0;

text-transform:uppercase;

}

.stripboxmenu a {

float: left;

display: block;

font: bold 12px Arial; /* Specify the font attributes like font style, boldness */

color: black; /* specify the color of the font */

text-decoration: none; /* remove the default underline of the anchor tag */

margin: 2 2px 2 2; /*Margin between each menu item, you can increase the spacing between the menus by adjusting the attributes*/

padding: 7px 15px 7px 15px; /*with this we can increase the width of the menu item (blue background)*/

background-color: lightblue; /*menu color*/

border-bottom: 9px solid white;

}

.stripboxmenu a:hover{

background-color: #f98a10; /*Mouseover color*/

padding-top: 20px; /*increase the height of the menu on mouseover using padding attribute */

border-bottom-color: #f98a10;

color: white;

}

/*Specify the style for current tab*/

.stripboxmenu .current a{

background-color: #000000;

padding-top: 12px;

border-bottom-color: #000000;

color: white;

}

</style>

</head>

<body>

<div>

<ul>

<li><a href=”#” title=”home”>Home</a></li>

<li><a href=”#” title=”what we do”>What We Do</a></li>

<li><a href=”#” title=”services”>Services</a></li>

<li><a href=”#” title=”clients”>Clients</a></li>

<li><a href=”#” title=”contact us”>Contact Us</a></li>

</ul>

</div>

<br style=”clear: both;” />

</body>

</html>

Step 2: now run the file in any browser it will look like this

As the html is rendered as li and anchor link inside it we can have many li inside another li to have sub sub menus.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

Dot Net – How to upload excel sheet into databse using Dataset in ASP.NET

I thought of writing this blog post because there can a number of occasion where in you might need to upload something from word file or excel sheet or it can be any kind of  file need to be inserted into the database what we can do many things.

But probably what I feel good and follow most of the time is doing this way so that we can preserve the statements for future reference what we have actually used and where it is going to exactly affect.

Step 1: Create  a website and then add default page on to it.

Step 2: Write the following code in Page_Load(object sender, EventArgs e) function

DataSet ds = new DataSet();

OleDbConnection myCon = new OleDbConnection(@”Provider=Microsoft.Jet.OLEDB.4.0;Data Source=folderpath\sheet.xls;Extended Properties=Excel 8.0;”);

OleDbCommand myComm = new OleDbCommand(“select * from [sheet1$] where State<>””, myCon);

OleDbDataAdapter da = new OleDbDataAdapter(myComm);

da.Fill(ds);

for (int i = 0; i < ds.Tables[0].Rows.Count;i++ )

{

Response.Write(“insert into dbo.Temp2 values(‘” + ds.Tables[0].Rows[i][0].ToString() + “‘,'” + ds.Tables[0].Rows[i][1].ToString() + “‘,'” + ds.Tables[0].Rows[i][2].ToString() + “‘,'” + ds.Tables[0].Rows[i][3].ToString() + “‘)<br />”);

}

myCon.Close();

Step 3: Create a table in SQL Server names Temp2 where in u want insert the excel sheet into.

NOTE: The table name can be any name  you like its just an example never take it as standard, its for learing.

create table Temp2(Id varchar(10),country varchar(100),natAnimal varchar(50),lang varchar(50))

Step 4: Create or if u have  excel sheet just make sure that that contains header for each column it will be easy to understand

EX:

State Country Animal Language
1 Australia Kangroo English
2 India Peacock Hindi
3 USA American Biston English

This is a sample excel sheet name it as sheet and inside as Sheet1 it will be applied by default so just hit the save button.

So all set!!!

now save the excel sheet in the folder of your website and run the web site the expected Output will be something like this will appear in your broswer

insert into dbo.Temp2 values(‘1′,’Australia’,’Kangroo’,’English’)

insert into dbo.Temp2 values(‘2′,’India’,’Peacock ‘,’Hindi’)

insert into dbo.Temp2 values(‘3′,’USA’,’American Biston’,’English’)

then copy it and paste in ssms (SQL server Query Editor and hit F5 to execute) Finally records are inserted into the database.

There can be many more ways I am sure but this is also handy when you have production and development section seperate.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

DotNet FrameWork – What actually happens when you add something to an arraylistcollection – How Boxing and unboxing occures in memory – Why only boxed types can be unboxed – Day 30 of 30

What actually happens when you add  something to an arraylistcollection ?

Following things will happen :

Arraylist is a dynamic array class in c# in System.Collections namespace derived from interfaces – ICollection , IList , ICloneable , IConvertible  . It terms of in memory structure following is the implementation .

a. Check up the total space if there’s any free space on the declared list .

b. If yes add the new item and increase count by 1 .

c. If No Copy the whole thing to a temporary Array of Last Max. Size .

d. Create new Array with size ( Last Array Size + Increase Value )

e. Copy back values from temp and reference this new array as original array .

f. Must doing Method updates too , need to check it up .

What is Boxing and unboxing? Does it occure automaatically or u need to write code to box and unbox?

Boxing – Process of converting a System.ValueType to Reference Type , Mostly base class System.Object type and allocating it memory on Heap .Reverse is unboxing , but can only be done with prior boxed variables.

Boxing is always implicit but Unboxing needs to be explicitly done via casting , thus ensuring the value type contained inside .

How Boxing and unboxing occures in memory?

Boxing converts value type to reference type , thus allocating memory on Heap . Unboxing converts already boxed reference types to value types through explicit casting , thus  allocating memory on stack .

Why only boxed types can be unboxed?

Unboxing is the process of converting a Reference type variable to Value type and thus allocating memory on the stack . It happens only to those Reference type variables that have been earlier created by Boxing of a Value Type , therefore internally they contain a value type , which can be obtained through explicit casting . For any other Reference type , they don’t internally contain a Value type to Unboxed via explicit casting . This is why only boxed types can be unboxed .

Please read all the post in the Dotnet Framework series.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

DotNet FrameWork – What is the difference between typeof(foo) and myFoo.GetType() – Day 28 of 30

What is the difference between typeof(foo) and myFoo.GetType()?

Typeof is operator which applied to a object returns System.Type object. Typeof cannot be overloaded white GetType has lot of overloads.GetType is a method which also returns System.Type of an object. GetType is used to get the runtime type of the object.

Example from MSDN showing Gettype used to retrive type at runtime:-

public class MyBaseClass: Object {   ………………..   }

public class MyDerivedClass: MyBaseClass {  ………………   }

public class Test {

public static void Main() {

MyBaseClass myBase = new MyBaseClass();

MyDerivedClass myDerived = new MyDerivedClass();

object o = myDerived;

MyBaseClass b = myDerived;

Console.WriteLine(“mybase: Type is {0}”, myBase.GetType());

Console.WriteLine(“myDerived: Type is {0}”, myDerived.GetType());

Console.WriteLine(“object o = myDerived: Type is {0}”, o.GetType());

Console.WriteLine(“MyBaseClass b = myDerived: Type is {0}”, b.GetType());

}

}

/*

This code produces the following output.

mybase: Type is MyBaseClass

myDerived: Type is MyDerivedClass

object o = myDerived: Type is MyDerivedClass

MyBaseClass b = myDerived: Type is MyDerivedClass

*/

Can “this” be used within a static method?

No ‘This’ cannot be used in a static method. As only static variables/methods can be used in a static method.

Please read all the post in the Dotnet Framework series.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )