Just Started in .net

Web.config Changes after installing membership tables

2008-12-13T03:01:00.000-08:00

After installing memership tables as illustrated in my previous blog 'Creating Membership Tables' we need to make changes in the web.config file as follows

The above code will remove the default database aspnetdb.mdf and point to new database where we are storing membership tables.

Creating Membership Tables

2008-10-21T09:19:00.000-07:00

When you create a new ASP.NET 2.0 web site using Visual Studio 2005, you'll observe that a new folder App_Data gets created in the solution explorer, namely the aspnetdb.mdf file gets created. This extra database holds all the tables and stored procedures to let Membership, Roles, Profile etc run smoothly.

When the website is live and we want to use aspnetdb.mdf, we need to have an extra database webserver. Because of this reason we would like to have same database for tables and procedures of memebership and any other purpose that your site requires.

We have a possibility to have membership tables in a single database with the command aspnet_regsql.exe.

We need to follow the below steps to install membership tables in your database with the command aspnet_regsql.exe.

Goto to the Visual Studio 2005 command Prompt.

MicrosoftSoft Visual Studio 2005->
Visual Studio Tools ->

Visual Studio 2005 Command prompt

Below is the command prompt window that gets opened and run the command aspnet_regsql.exe

Soon after you run the command, you will find the 'Welcome to the ASP.NET SQL server setup Wizard ' window opened.

Click next.

After clicking next 'Select a Setup Option' window gets opened.

Select the default or the other option depending upon the requirement.

Click next and note the 'Select the Server and Database' window gets opened.

Select the database and click next.

Note 'confirm your settings' window gets opened.

Confirm your settings and click next otherwise, go to previous window and change the settings.

Click next and note 'The database has been created or modified' window has been opened.

click finish.

Check the required tables are populated in the specified database.

How to disable right click

2008-04-09T00:12:00.000-07:00

We can disable right click of our web pages through

document.oncontextmenu=new Function("return false;")

Access Specifiers in .net

2008-03-11T10:28:00.000-07:00

The main purpose of using access specifiers is to provide security to the applications. The availability (scope) of the member objects of a class may be controlled using access specifiers.

PUBLIC

As the name specifies, it can be accessed from anywhere. If a member of a class is defined as public then it can be accessed anywhere in the class as well as outside the class. This means that objects can access and modify public fields, properties, methods.

PRIVATE

As the name suggests, it can't be accessed outside the class. Its the private property of the class and can be accessed only by the members of the class.

INTERNAL

Friend & Internal mean the same. Internal is used in C#. Friends can be accessed by all classes within an assembly but not from outside the assembly.

PROTECTED

Protected variables can be used within the class as well as the classes that inherites this class.

PROTECTED INTERNAL

The Protected Internal can be accessed by Members of the Assembly or the inheriting class, and ofcourse, within the class itself.

Execution process in .net

2008-03-11T09:50:00.000-07:00

.NET applications aren’t executed the same way as the traditional Windows applications you might be used to creating.

Instead of being compiled into an executable containing native code, .NET application code is compiled into Microsoft intermediate language (MSIL) and stored in a file called an assembly.

At run time, the assembly is compiled to its final state by the CLR.

While running, the CLR provides memory management, type-safety checks, and other run-time tasks for the application.

Applications that run under the CLR are called managed code because the CLR takes care of many of the tasks that would have formerly been handled in the application’s executable itself.

Types of Applications in .net

2008-03-11T09:02:00.000-07:00

There are four types

Web applications

These applications provide content from a server to client machines over the Internet. Users view the Web application through a Web browser.

Web services

These components provide processing services from a server to other applications over the Internet.

Internet-enabled applications

These are stand-alone applications that incorporate aspects of the Internet to provide online registration, Help, updates, or other services to the user over the Internet.

Peer-to-peer applications

These are stand-alone applications that use the Internet to communicate with other users running their own instances of the application.

How to change Default DataBase in SQL Server 2005

2008-02-05T23:47:00.000-08:00

ALTER LOGIN [Login_Name] With default_database = [Database_Name]

Example:-

alter login sa with default_database = ourspace

How to Alter a column DataType in SQL Server 2005

2008-02-05T23:41:00.000-08:00

USING [Database_Name]
ALTER TABLE [Table_Name]
ALTER COLUMN [ Field_Name] New_Datatype

Example :-

ALTER TABLE myTable
ALTER COLUMN fieldname nvarchar(255)

Adding a column to a existing Table in SQL Server 2005

2008-02-05T23:34:00.000-08:00

USE [Database_Name]
ALTER TABLE [Table_Name]
ADD [Column_Name] Datatype null

Example:-

USE ourspace
ALTER TABLE items ADD Brand varchar(100) null

How to disable Back button of Internet Explorer

2008-02-01T02:17:00.000-08:00

There is no direct way to disable the back button so that it is greyed-out and user cannot click on it.

However, there are some tricks using javascript which might be able to give you the results that we need, using javascripts window.history function with a session variable and automatically logging off and redirecting to the required page if user hits the back button.

javascript code

window.history.forward(1);

Difference between ReadOnly and Constants

2008-01-31T03:58:00.000-08:00

Difference between ReadOnly and Constants

-> A constant is initialized at the time of its creation i.e Compile Time.

-> A ReadOnly can be assigned once in the class constructor allowing you to pass the value at Runtime.

Advantages of declaring Constant

->Declaring fields as constants protects from changing the value accidentally.

->Using constants we perform some optimization by not declaring any stack space for that field.

Validating EMail Id - Java Script Code

2008-01-08T21:58:00.000-08:00

Validating EMail ID

Some times we want users to enter their EMail Id and we require it to validate.
The following code in java script will help you out.

Add a TextBox to enter email id and a Button (which has to be clicked by the user after entering email address) in .aspx page.

In the given example txtEmail is the id of the text box and btnEmailCheckOut is the id of Button.

In the Code behind .aspx.cs page add the below code in Page_Load event-
btnEmailCheckOut.Attributes.Add("onclick", "javascript:return CheckEmail('" + txtEmail.ClientID + "');");

The above code adds attribute to the button so as to execute a javascript function when the button is clicked. JavaScript function CheckEmail takes a parameter txtEmail.ClientID(id of TextBox which will hold Email Id).

Here's the java script function starts

function CheckEmail(ControlID)
{
var str=document.getElementById(ControlID).value;
if (str != "" )
{
var at="@"
var dot="."
var lat=str.indexOf(at)
var lstr=str.length
var ldot=str.indexOf(dot)

if (str.indexOf(at)==-1)
{
alert("Invalid E-mail ID");
document.getElementById(ControlID).focus();
return false;
}
if (str.indexOf(at)==-1 str.indexOf(at)==0 str.indexOf(at)==lstr)
{
alert("Invalid E-mail ID");
document.getElementById(ControlID).focus();
return false;
}
if (str.indexOf(dot)==-1 str.indexOf(dot)==0 str.indexOf(dot)==lstr str.lastIndexOf(dot)==lstr)
{
alert("Invalid E-mail ID");
document.getElementById(ControlID).focus();
return false;
}
if (str.indexOf(at,(lat+1))!=-1)
{
alert("Invalid E-mail ID");
document.getElementById(ControlID).focus();
return false;
}
if (str.substring(lat-1,lat)==dot str.substring(lat+1,lat+2)==dot)
{
alert("Invalid E-mail ID");
document.getElementById(ControlID).focus();
return false;
}
if (str.indexOf(dot,(lat+2))==-1)
{
alert("Invalid E-mail ID");
document.getElementById(ControlID).focus();
return false;
}
if (str.indexOf(" ")!=-1)
{
alert("Invalid E-mail ID");
document.getElementById(ControlID).focus();
return false;
}
return true;
}
}

Explanation

function CheckEmail(ControlID)
ControlID is the id of TextBox which will hold EMail ID.

var str=document.getElementById(ControlID).value;
document.getElementByID(ControlID) will Returns the reference to the element whose ID is specified.

document.getElementById(ControlID).value give us text entered in the textbox.
So, str will contain Email Id entered by the user in the text box.

if (str != "" )
checks whether str is null or not.

var lat=str.indexOf(at)
str.indexOf(at) gives first index(position) of at('@').
lat holds the index.
similarly,

var ldot=str.indexOf(dot)
ldot contains index of dat(' . ');

var lstr=str.length
str.length returns length of the str(EMail Id )

if (str.indexOf(at)==-1)
{
alert("Invalid E-mail ID");
document.getElementById(ControlID).focus();

return false;
}
Above fuctions checks whether '@' is present in EMail id or not if not it will show an alert message as shown below.

str.indexOf(at) checks for the first occurance of '@' if there is no occurance of '@' returns -1;

EMail Id should definitely contain @ otherwise it not valid.

document.getElementById(ControlID).focus();

focus() method will place cursor into the specified element .TextBox in the current context.

return false; Every function of javascript should return true or false.

If we wont mention return false; statement, function CheckEmail will be called repetedly and alert message will pop up as soon as we have closed early instance of alert message.

if (str.indexOf(at)==-1 str.indexOf(at)==0 str.indexOf(at)==lstr)

Above function will check whether there is any occurances of '@' or not and if ocuurance of '@' is equal to the length of the EMail ID i.e EMail ID ending with '@' which is absurd if, any of the condition is true then EMail Id is not valid.

if (str.indexOf(dot)==-1 str.indexOf(dot)==0 str.indexOf(dot)==lstr str.lastIndexOf(dot)==lstr)

Above function will check the ocurrances dot(' . ') is there or not and checks whether EMail Id is ending with dot or not.

if (str.indexOf(at,(lat+1))!=-1)

checks whether '@' occurs immediately after the first occurance of '@' .

sam@@yahoo.com is the invalid EMail Id.

if (str.substring(lat-1,lat)==dot str.substring(lat+1,lat+2)==dot)

The above statement checks whether the dot is followed immediately before or after at.

e.g. sam.@yahoo.com or sam@.yahoo.com

if (str.indexOf(" ")!=-1)

The above statement checks whether the statement contains any blank space or not.If you want some special character should not be there in your email id then use

if(str.indexOf("SPECIAL CHARACTER ")!=-1)

Query String

2008-01-08T21:28:00.000-08:00

Passing Query String in the Source Page

If we want to pass some values to another page it is possible through query string.
Query string is a string which is appended after the URL.
E.g. Response.Redirect( Sample.aspx?name=sam&age=21&sex=female);

In my previous post I have explained that Response.Redirect is used to move from one webpage to another webpage.
Sample.aspx is the destination page to which we want to migrate.
Query string is appended just after the URL, beginning with “?”

?name=sam&age=21&sex=female is the query string in the above example where Sample.aspx is the URL and name, age, sex are the parameters with their values sam, 21,female respectively .

Two parameters are separated by ‘&’ in the above example name and age are two different parameters and they are separated from ‘&’.
?name=sam&age=21

Value to the parameter is assigned after equal to (“=”).
?name=sam
Here name is parameter and sam is value assigned to the parameter.

Retrieving Query string in the Destination Page

Query string is retrieved by a command Request.QueryString(“parameter”) in asp.net

e.g. Request.QueryString["id"]

The first thing we do is to check if the query string exists in the first place before we start using it. It could look like this:
if (Request.QueryString["id"] != null)
{
// Do something with the querystring
}

The only problem with the above check to see if the query string is null, is that we don't take into consideration if the query string is filled or not.

That could lead to unhandled exceptions in the code. Instead we should check for query strings like this:

if (!String.IsNullOrEmpty(Request.QueryString["id"]))
{
// Do something with the querystring
}

So we do the check again more thoroughly:

if (!String.IsNullOrEmpty(Request.QueryString["id"]) && Request.QueryString["id"].Length == 5)
{
// Do something with the querystring
}

Now we know that we get a query string suitable for further processing.
You can then do more precise data type checks using the Parse or Convert method of most value types or by some other logic.

SqlClient.SqlException - An error has occurred while establishing a connection to the server

2007-12-20T22:52:00.000-08:00

An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, This failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

If you are new to .net you will surely face the following error.

Solution for the error as follows

Follow the path

Start -> All Programs
-> Microsoft SQL server 2005
-> Configuration Tools
->SQL Server Surface Area Configuration

Now you will be land to SQL Server 2005 Surface Area Configuration window.

Now Click
Surface Area Configuration for Services and Conditions(2nd bottom).

Soon you will land to SQL Server 2005 Surface Area Configuration window
Goto
DataBase Engine -> Remote Connections

By Default Local Connections only will be selected.

Change it by selecting Local and remote connection.
Options under Local and remote connection will be by default Using TCP/IP only.

Select the last option
Using both TCP/IP and named pipes.

click apply and then ok.

Dont Forget to Restart SQL Server.

Page Navaigation In .Net 2.0

2007-12-20T21:45:00.000-08:00

WebPage Navigation

You may be wondering how we do perform page navigations especially in the code behind I mean without html controls or asp.net controls. We have few Commands that need to be remembered and should be used depending upon our requirement.

Server.Transfer is similar to Response.Redirect in sense that it sends the user to another page with a statement such as Server.Transfer("WebForm2.aspx"). However, the statement has a number of distinct advantages and disadvantages.

Firstly, transferring to another page using Server.Transfer conserves server resources. Instead of telling the browser to redirect, it simply changes the "focus" on the Web server and transfers the request. This means you don't get quite as many HTTP requests coming through, which therefore eases the pressure on your Web server and makes your applications run faster.

"transfer" process can work on only those sites running on the server, you can't use Server.Transfer to send the user to an external site. Only Response.Redirect can do that.

Secondly, Server.Transfer maintains the original URL in the browser. This can really help streamline data entry techniques, although it may make for confusion when debugging.
The Server.Transfer method also has a second parameter—"preserveForm". If you set this to True, using a statement such as Server.Transfer("WebForm2.aspx", True), the existing query string and any form variables will still be available to the page you are transferring to.

For example, if your WebForm1.aspx has a TextBox control called TextBox1 and you transferred to WebForm2.aspx with the preserveForm parameter set to True, you'd be able to retrieve the value of the original page TextBox control by referencing

Request.Form("TextBox1").

In brief Response.Redirect simply tells the browser to visit another page. Server.Transfer helps reduce server requests, keeps the URL the same and, with a little bug-bashing, allows you to transfer the query string and form variables.

Creating 3-Tier Architecture in .NET

2007-11-28T02:24:00.000-08:00

Today I would like to write about how to create Three-Tier architecture
Guys who have just started working on .net may have questions in their minds
What is this ‘three tier architecture?, Why three tier architecture? Why to follow it.? and so on……………….

I was in the same illusion when I have started working on .net and told to follow it.

There are many reasons to tell why we need an architecture .I want to tell you few of that I know:-
1) To make our code more modular.

2) Readability increases.

3) Fixing bugs is easier.

4) To follow certain standard’s.

I would like to illustrate how to and what is the need to follow.
Architecture may not be of three tiers always .It has been chosen to follow because it may be a clients request or company standards. But it is always better to have an architecture for your project and to follow specific standards through out the project.

Three tier architecture looks like.

1) UIL(User Interface Layer)

2) BLL(Business Logic Layer)

3) DAL(Data Access Layer)

Now we shall start building the specified architecture. Firstly choose the location where you want your project to be placed, location can be in any partition of your memory (like C drive or D drive ………). Create a folder in that specific drive and name the folder that you have chosen for your project.

NOTE: Remember always choose project name that best describes your project and it must be appropriate.

Create two subfolders Named CompleteBuild(optional name) and Database.
Place all procedure in the database folder and create a folder called UIL in the CompleteBuild.

Creating Virtual Directory

Now go to run (windows key + r), type inetmgr then press enter.You will be able to view the IIS window as below.

On the left side of the window you can view local computer, expand it you will observe Web Sites and then choose Default Web Sites to expand .Move the mouse over Default Web Site link right click then select New option from that select and Click Virtual Directory.......

local computer -> Web Sites -> Default Web Site -> (right click and choose) New -> Virtual Directory

Now you will observe another window which will be similar to this image.

Click on next.

Now it will ask you to give alias name .Choose an appropraite name to fill the text box.
After filling text box click on next .

Now you need to enter physical path of your project where it is located.
like C:\OurSpace\Complete Build\UIL
After done, click on next.

Just check Browse option in the access permissions window and dont do any thing else.
Done with it, then click on next.

Virtual directory has been created successfully if you get this window.
Click on finish .

You can now see the virtual directory with the alias name you have given has been created in ths Defaut web sites (left side) and in the content side you will have no content but, if you are placing any files in UIL you can very well view them and browse depending upon the the permissions you have given in Access Permission Window.

Now, go to visual studio IDE choose New ->Web Site

you will be landing into this window choose ASP.NET Web Site or AJAX Enabled Web Site depending on your requirement.

Now look at the left-bottom of the window you will find location dropdown, select http then click on browse

you will find this window choose the physical directory you have just created.

Note:- you can only find virtual directory when you select IIS tab, which is located at the left side is selected.

Now we have to create two more layers BLL and DAL.These BLL and DAL are nothing but Class Library.Go to the solution explorer window, move your mouse on the Solution File then right click select Add -> Add New Project option you will find the window as shown .Choose

the location C:\OurSpace\CompleteBuildand name it as BLL.

Repeat the same for DAL layer.

We have created the three layers , now we need to set properties and relation among them.

Now go to the UIL right click to choose properties.

Choose Reference located at the left side.
when the window pops up click on Add Reference button.

Choose the projects tab, select BLL and

DAL(i have used EnterPrise Library instead of DAL)then click on ok.

Choose MS Build option from the left side and update Output Folders as C:\OurSpace\CompleteBuild\SolutionFiles\PrecompiledWeb\UIL and relate correspondingly yours donot exactly cut copy paste.

Go to solution file right click and choose properties select Project Dependencies tab located left side of the window.

select project

UIL

Check Depends On BLL

similarly select project BLL and check Depends On DAL and there is no need for DAL to set any property as it does not depend on any project, neither UIL nor BLL.

Now we have successfully created the specified architecture. If you haven't try, just try it you will surely make sense.

Why .NET

2007-11-27T08:56:00.000-08:00

Hi Friends ,
Let me tell you why i have chosen .net as platform .

WHY .NET

.NET is the future of development not only for the Windows platform, but other operating systems as well. If you are not moving to .NET now, you should at least be keeping up to date with it and reevaluating it at regular intervals to determine when you will begin moving to it.

Some advantages that .net has over Java are:

Java is not just a platform, but a language। .NET is language independent.

Adopting .NET does not force you to adopt a single, or even specific .we can even support the Java language, and J# is very close to Java.
Language interoperability.

.NET can coexist with and even integrate with existing Win32 code.
Moving to Java from Win32 is a complete paradigm shift.

Moving to .NET is a more natural path for Win32 developers.

Technical Components Making Up The .NET Platform:

C#, a "new" language for writing classes and components, that integrates elements of C, C++, and Java, and adds additional features, like metadata tags, related to component development.

A "common language runtime", which runs bytecodes in an Internal Language (IL) format. Code and objects written in one language can, ostensibly, be compiled into the IL runtime, once an IL compiler is developed for the language.

A set of base components, accessible from the common language runtime, that provide various functions (networking, containers, etc.).

ADO+, a new generation of ADO data access components that use XML and SOAP for data interchange.

Win Forms and Web Forms, new UI component frameworks accessible from Visual Studio

ASP+, a new version of ASP that supports compilation of ASPs into the common language runtime (and therefore writing ASP scripts using any language with an IL binding).