Data Source Controls

Data Source controls are asp .net controls that allow you to connect to a database, retrieve or update data inside the database without writing any code. Thus Data source controls implemented all those downs and ups used in direct data access. More interestingly data source controls work with data oriented list controls (data-bound controls) with ease.
Data source controls handle operations like: 

• Managing connection
• Data retrieval and update
• Data presentation etc

.Net framework includes these data source controls:

• SqlDataSource -used for Sql Server, Oracle, OleDb and ODBC
• AccessDataSource - used for Ms Access
• ObjectDataSource - custom data access class(es)
• XmlDataSource -used for xml files
• SiteMapDataSource - used for sitemap data source

In this note I'll be considering SqlDataSource.To use SqlDataSource controls you need to provide certain values including connectionString, ProviderName and command (SelectCommand, UpdateCommand, DeleteCommand or InsertCommand). All these is usually done inside your aspx markup page:

<asp:SqlDataSource ID="SqlDataSource1" runat="server"

            ConnectionString="<%$ ConnectionStrings:DatabaseConnectionString %>"

            ProviderName="System.Data.SqlClient"

            SelectCommand="SELECT [DName], [Dcode] FROM [Departments]">

</asp:SqlDataSource>

 In the above connectionString you provide the name of your connectionString (probably stored inside web.config) like the one I underlined.

Now after this point what is remaining is how to bind to another control that uses the retrieved data and may provide data to update. Let us use a dropdownlist to display the list of departments:

<asp:DropDownList ID="DropDownList1" runat="server"

      AppendDataBoundItems="True" DataSourceID="SqlDataSource1"

      DataTextField="DName" DataValueField="Dcode">

      <asp:ListItem Selected="True" Value="Select">Select . . .</asp:ListItem>

</asp:DropDownList>

Inside the above markup DataSourceID="SqlDataSource1" is telling the dropdownlist where to find the data while  DataTextField="DName" and DataValueField="Dcode" tells which column to use for display text and which one to use for item's value respectively. The AppendDataBoundItems="True" on the other hand dictates the dropdownlist to not only use data from database but also append another additional data to be added at design time or at runtime. Now we've added an item <asp:ListItem Selected="True" Value="Select">Select . . .</asp:ListItem> at design time.

The result should look like:

 Go to this links to see more: 
 Data Source Controls, Part 1: The Basics

 Data Source Controls Overview 

 

ASP .net Data Binding

Data binding at first is a mechanism  by which you can bind, synchronize or link data with user interface (controls).
In ASP.net there are two types of data binding:

1. Single-Value (Simple) Data Binding
2. Repeated-Value (List) Data Binding

Single-Value Data binding

Allows you to take a variable, a value returned by a method or an expression and place it dynamically inside the user interface of a webform.

Syntax:    <%# your_expression %> 

this example can be a footer on a website 

<div style="text-align:center;">

    CopyRight &copy;<%#DateTime.Now.Year %>. Nuux

</div>

      the output should look like:

                              CopyRight©2011. Nuux

Note that the year is not constant it will change with the server's date.

Data binding to work requires to be activated explicitly. To activate data binding call a method known as Databind() for each control as ctrl.Databind() or once for all controls as Me.Databind() or simply Databind()in which case the owner object is implied as Me (the current page (this in C#)). So call this method in your Page load event like the following example. It is better practice to place the method below your code.

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        'Your code goes here

        Me.DataBind()

    End Sub

 If you have got variables or methods you want to show or use their values on your interface make sure they are declared with either of these access modifiers: Public, Protected or Friend. You cannot access objects with private access in your interface.

Control properties can be set by data binding: Try this:

<asp:TextBox id="txt1" runat="server" />

<asp:Label id="labelOne" Text="<%# txt1.Text %>" runat="server" />

<asp:Label id="labelTwo" Text="<%# DateTime.Now %>" runat="server" />

Repeated-Value Data binding

Repeated-Value data binding works with list controls. By the way, there are two types of list controls in asp.net:

1. Simple List Controls eg: ListBox,DropDownList, RadioButtonList etc
2. Rich Data List Controls eg: GridView,ListView, DetailsView and FormView

These controls expose a number of properties and methods for data binding purpose.You can bind these controls to almost any structure that support the IEnumerable interface. The data sources for this controls include: Collection,array, arraylist, DataTable, DataView,DataReader, HashTable and DataSet.

Data binding can be done at design time or at runtime. 

For a good explanation this might help you: Data Binding - The Concepts

 

ADO.NET II - DIRECT DATA ACCESS

Building SQL commands and using ADO.NET classes to access database without the need of data oriented controls is considered as direct data access.

There are a number of steps you should follow to achieve direct data access:

1. Import relevant namespace
2. create an instance object of SqlConnection class
3. set the ConnectionString property of the connection object
4. Open the connection
5. Create an instance object of SqlCommand
6. set the CommandText property of the command with your sql statement
7. set the Connection property of the command object with the SqlConnection object you’ve created
8. execute the command

If you are retrieving data (i.e: if you are using Select sql statement) you need to use SqlDataReader class to extract the data from the SqlCommand:

9. create a variable object of type SqlDataReader. Note: SqlDataReader does not use the new keyword that means it has no constructor
10. Execute command reader. Command reader (SqlCommand.ExecuteReader() ) is a method that executes the command against the database and at the same time returns a SqlDataReader with the result
11. Traverse the rows of SqlDataReader one after one by using Read() method
12. after you call the Read() method use the data in the reader by column index or name
13. close the reader and the connection if you are done (important)

Example:

Imports System.Data.SqlClient

Partial Class CustDetails

    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        'Dim id As String

        'id = Request.QueryString("id")

        Dim conn As New SqlConnection()

        conn.ConnectionString = "Data source=(local)\sqlexpress; AttachDbFilename=|DataDirectory|\Database.mdf;" _

        & "Integrated Security=true; User Instance=true;"

        conn.Open()

        Dim cmd As New SqlCommand()

        cmd.CommandText = "select * from Customers where custid='12'"

        'cmd.Parameters.AddWithValue("@cust", id)

        cmd.Connection = conn

        Dim drdr As SqlDataReader

        drdr = cmd.ExecuteReader()

        drdr.Read()

        If drdr.HasRows Then

            lblCustID.Text = drdr("custID").ToString()

            lblCustName.Text = drdr("fname").ToString()

            lblCustSurname.Text = drdr("lname").ToString()

        Else

            lblError.Text = "No customer found with the stated ID"

        End If

        drdr.Close()

        conn.Close()

    End Sub

End Class

For how to use Parameters go to my channel http://youtube.com/nuux14

ADO.NET I

ADO.NET is a set of classes designed to access data sources.
We have two categories of these classes:

1. Data Container classes: these classes are merely used for temporary data storage. Data retrieved from database are stored in these classes. Beyond that data container classes can act like your database by maintaining relationships between tables (offline tables not real database tables). This is sometimes referred as Disconnected architecture. These classes include: DataSet
2. Data Connection classes (Data Providers): these classes are the concrete tools to work with data sources. Data providers help us establish connection with our database, retrieve data, update and many related tasks. These classes include: [provider]Connection.

In ADO.NET we have four Data Providers:

1. Sql Data Provider
2. Oracle Data Provider
3. OleDb Data Provider
4. ODBC Data Provider

The main common classes in all data providers are: Connection, Command, DataAdapter, & DataReader.

Sql Data Provider:

• SqlConnection - to establish a connection to our database. This is the first task when we want to deal with database. If the connection is established successfully you have cut a major part of your journey. As a rule every opened connection must be closed after usage. ConnectionString is a property of this class that needs to be set with a number of parameters passed with their values. After this you call Open() method to establish the connection and to disrupt it you call Close() method.
• SqlCommand - to execute sql statements (commands) against the database.This is second task you should do. Two properties need to be set to use this class. The CommandText is set with an sql statement string. The Connection is set with the connection object we have created.
• SqlDataAdapter- it is a bridge between database and dataset.
• SqlDataReader - to read the data returned by SqlCommand

Connection String
To establish a successful connection we need to understand the different ways to construct connection string based on different DBMSs & their different versions. Basically we need to set and pass at least the following parameters in the connection string:

• Data Source - the name or the address where the database is residing.
• Initial Catalog , Database or AttachDbFilename - the name and the path of the database file
• Integrated Security - the type of authentication to use. We have two types of authentication here. Windows Authentication and SQL Server Authentication. If you set this parameter to true you want to use Windows Authentication which is recommended otherwise you are using SQL Server Authentication which requires you to provide two other parameters namely User ID and Password.
• User Instance - you set this to true if your database is not in the master list of sql server. This means roughly your database is not attached to the sql server.

Let us go down: when building connection string you need to consider the version of sql server you are using and whether or not your database is attached to the sql server.

Option 1: You are using Full version of SQL Server

Criteria:  your database must be attached to the sql server
 Example connection string:

Dim conString As String

conString = "Data Source=(local);Initial Catalog=yourdatabase.mdf;" _ 

& "Integrated Security=true;"

Option 2: You are using SQL Express and Database is attached to server

Example connection string

Dim conString As String

conString = "Data Source=(local)\SQLExpress;Initial Catalog=yourdatabase.mdf;" _ 

& "Integrated Security=true;"

Option 3: You are using SQL Express and Database is not attached to server

Exmaple connection string

Dim conString As String

conString = "Data Source=(local)\SQLExpress;" _ 

& "AttachDbFilename=|DataDirectory|\yourdatabase.mdf;Integrated Security=true;"_ 

& "User Instance=true;"

Watch a little explanation in Somali

How to Redirect or Send a User from Current Page to Another Page

Of course we can use the traditional way of Html redirection in asp.net web forms but some times you need a more controlled redirection. For instance, you want to validate a user input using the server side code before you send the user to the desired page. At this time you need a kind of, let me say, deferred redirection. There are a number of alternatives to do this and that in asp.net web forms.

We can use the html anchor tag as usual to make unconditional redirection meaning that the user once he/she clicks the link is directly redirected or sent to the navigation url.

    <a href="Order.aspx" target="_blank"> Go to Order</a>

Asp.net has a similar control known as HyperLink

<asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl="~/Order.aspx">Go to Order</asp:HyperLink>

We can also use the PostBackUrl property of button controls ( Button, ImageButton, & LinkButton)

So you can set this property directly in the control at design time or inside code file at runtime.

<asp:LinkButton ID="LinkButton1" runat="server" PostBackUrl="~/Default.aspx">Go to Home</asp:LinkButton>

Or in the LinkButton1 click event or in any other event of the page and its controls just like this:

 

Protected Sub LinkButton1_Click(ByVal sender As Object, ByVal e As System.EventArgs)

 Handles LinkButton1.Click

        ' your other code goes here

        LinkButton1.PostBackUrl = "~/Default.aspx"

    End Sub

Look at the above controls carefully. You’ll notice that the first two controls used the NavigateUrl property while the button controls used the PostBackUrl property. Yes there is a reason why these controls use different properties though they are all meant to send the user to another page. The reason is the above controls (<a> html tag and the HyperLink asp.net control) do not cause the current page to be sent to the server while PostBackUrl, as the name suggests, first send the current page to the server and then, if the server code doesn’t stop the redirection, sends the user to the specified url (page). If you are asking what is the purpose of posting back the current page to the server, the answer can be sometimes you may need to have control over the redirection that is you may have some content to submit first before sending the user to another location. For example, if you are validating form input in server code you may need to stop the redirection and send error messages back to the current page. In other terms, anchor tag and HyperLink control do not cause validation that means the user skips the validation errors and is able to jump to the url specified by these tags while button controls cause validation and will not allow the user to navigate away from the current page (Note: you can stop buttons from causing validation by setting the CausesValidation property to false).

Request.Redirect("url") and Server.Transfer("url") are methods that made possible to redirect users without the need of any tag or asp.net control. Request and Respond are properties of the Page class. These properties will enable us redirect users at any time in our code. For example, we will redirect a user directly to another page before the user can see the page he/she requests.

Put this line of code in one of the pages events that occur before the page is rendered to the browser:

Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init

        Response.Redirect("~/Order.aspx")

End Sub

Or put the statement in the Page.Load event after you perform some operations. Remember in both events you will not be able to see the requested page (i.e: if you request http://localhost/MyWebsite/default.aspx and you place that code in some event of the default page you will never be seeing the default.aspx web form)

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        Dim IMG As Image = CType(Master.FindControl("Image1"), Image)

        IMG.ImageUrl = "~/RememberAllah.png"

        Response.Redirect("~/Order.aspx")

End Sub

Database Design & Implementation

According to the syllabus of this course, the second major part is Working With Data. We can categorize this part into two main categories:

1. Database Design and Implementation
• Prepare data model normally Entity relationship diagram
• Prepare database schema which states the physical structure of our database
• Create the database based on the schema by using any DBMS we want
2. Database Manipulation 

•  Work with the database tables to insert, update, delete or retrieve data

As part of ASP.NET we will be dealing with the second category. To manipulate database the ADO.NET (one of the fascinating features of .NET framework) is our first choice. Database design is students' responsibility as it will help the student to exercise real application of database concepts. However, I have written a simple design of each system and you can use as an alternative.
 Now we have four different projects one for each class:

1. Hotel Room Reservation System
2. University Registrar System
3. Online Shopping System
4. Airline Booking System

I have tried to present you with the simplest design of each of these systems.

    

Hotel Reservation System

In hotel reservation system we will be dealing with these two main entities and two weak entities:

Customers (CustId, Title, FName, LName, DoB, Tel, Email, city, countryRes, Nationality, PassNo)

Rooms (RoomId, Type, Price, Floor, Facilities, Notes)

Bookings (BookingID, CustId, RoomId, DateMade, TimeMade, StartDate, EndDate paid)

RoomsCustomers (CustId, RoomId, StartDate, EndDate, RegistrationDate)

University Registrar System

In registrar system we will be dealing with these entities:

Student(StudId, FName, LName, DoB, Gender, DCode, DoB, PoB, PrevEducation, PrevInstitution,         Program, ProgramType, City, Region, Tel, PoBox, Email, EmergencyContactName, EmergencyContactPhone, AppDate, Approved, ApprovalDate)

Department (DCode, DName, Major,Minor)

Employee (EmpId, FName, LName,DCode, Gender, Qualification, Position, Nationality, DoB, EmpType, EducLevel, HireDate, Tel, Email, PoBox)

Course (CourseNo, CourseName, CreditHour, AcadTermLevel,AcadYearLevel, DCode)

Term ( TermID,Term, AcadamicYear, StartDate, EndDate)

Note: for groups who are working on University Registrar System, tables used are more than the stated and that is left as a challenge for you. Study how your university's registrar system works and drive the rest of the tables.

 Online Shopping System

Products (ProdId, ProdName, Description, SupplierName, Category, Quantity, UnitPrice, Picture)

Customers (CustId, FName, LName, City, State, PostalCode, Country, Phone, Email, CreditCardType, CreditCardNo)

Orders (OrderId, CustId, OrderDate, ShipDate, RequiredDate, ShipperName, Paid)

OrderItems (OrderId, ProdId, Price, Quantity, Discount, ShipDate, OrderItemsId)

Airline Booking System

Passenger (Email, GivenName, SurName)

Airplane (RegNo, ModelNo, Capacity, Airline)

Flight( FlightNo, ModelNo, From, To, DepartTime, DepartDate, ArrivalTime, ArrivalDate)

Booking (Email, FlightNo, BookingDate, Status)

**********

Database Implementation

You have a number of options and a number of DBMS softwares but for now we will be using SQL Server Express edition as our DBMS. When you installed your web developer sql server express was also installed but with no graphic interface to use. Web Developer supports many features that enables us interact with the SQL Server. I am going to show you how you can use web developer to create and test your database.

Take these steps:

1.      Website > Add New Item > SQL Server Database > Add > Yes

2.      View > Database Explorer > Expand your database

3.      R-click on Tables folder > Add New Table

4.      Define fields for the table

5.      Define primary key constraint by R-clicking on the left side button before the column (field) you want to make primary key > set primary key > Save

To see how you can do this and how you can create relationships between tables watch this video:

if you don't want this way go to my channel http://youtube.com/nuux14 and find the video by title

Dynamically Changing Master Pages and their contents

Some times we may need to use different master pages for may be different users. To have this capability you need to have more than one master page inside your website first, and control which master page to display inside the code behind but you should select a default master page for each web form.

Suppose you have two different master pages one for students and the other for web administrator.
To change the master page of a web form you need to add this event to your code behind file

Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs)    Handles Me.PreInit

        If Request.QueryString("userName") = "Ahmed" Then

            Me.MasterPageFile = "~/MasterPage2.master"

        End If

    End Sub

Here I am changing the masterpagefile of the current web form iside its code file. I am using query string to identify which user logged in but this may not be the case when we manage users. We shall see this topic in the following chapters.

Also you can manage the contents inside the masterpage without the need to change the master page. So we need to access the controls inside the master page directly inside the content page to do this you should use the property Master ( which is an object) of the current page. Within that object we have the FindControl() method. See this example which changes the banner image displayed inside the masterpage:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        Dim IMG As Image = CType(Master.FindControl("Image1"), Image)

        IMG.ImageUrl = "~/RememberAllah.png"

    End Sub

 

ADO.NET

ADO.NET is a set of classes designed to access data sources.
We have two categories of these classes:

1. Data Container classes: these classes are merely used for temporary data storage. Data retrieved from database are stored in these classes. Beyond that data container classes can act like your database by maintaining relationships between tables (offline tables not real database tables). This is sometimes referred as Disconnected architecture. These classes include: DataSet
2. Data Connection classes (Data Providers): these classes are the concrete tools to work with data sources. Data providers help us establish connection with our database, retrieve data, update and many related tasks. These classes include: [provider]Connection.

In ADO.NET we have four Data Providers:

1. Sql Data Provider
2. Oracle Data Provider
3. OleDb Data Provider
4. ODBC Data Provider

The main common classes in all data providers are: Connection, Command, DataAdapter, & DataReader.

Sql Data Provider:

• SqlConnection - to establish a connection to our database. This is the first task when we want to deal with database. If the connection is established successfully you have cut a major part of your journey. As a rule every opened connection must be closed after usage. ConnectionString is a property of this class that needs to be set with a number of parameters passed with their values. After this you call Open() method to establish the connection and to disrupt it you call Close() method.
• SqlCommand - to execute sql statements (commands) against the database.This is second task you should do. Two properties need to be set to use this class. The CommandText is set with an sql statement string. The Connection is set with the connection object we have created.
• SqlDataAdapter- it is a bridge between database and dataset.
• SqlDataReader - to read the data returned by SqlCommand

Connection String
To establish a successful connection we need to understand the different ways to construct connection string based on different DBMSs & their different versions. Basically we need to set and pass at least the following parameters in the connection string:

• Data Source - the name or the address where the database is residing.
• Initial Catalog , Database or AttachDbFilename - the name and the path of the database file
• Integrated Security - the type of authentication to use. We have two types of authentication here. Windows Authentication and SQL Server Authentication. If you set this parameter to true you want to use Windows Authentication which is recommended otherwise you are using SQL Server Authentication which requires you to provide two other parameters namely User ID and Password.
• User Instance - you set this to true if your database is not in the master list of sql server. This means roughly your database is not attached to the sql server.

Let us go down: when building connection string you need to consider the version of sql server you are using and whether or not your database is attached to the sql server.

Option 1: You are using Full version of SQL Server

Criteria:  your database must be attached to the sql server
 Example connection string:

Dim conString As String

conString = "Data Source=(local);Initial Catalog=yourdatabase.mdf;" _ 

& "Integrated Security=true;"

Option 2: You are using SQL Express and Database is attached to server

Example connection string

Dim conString As String

conString = "Data Source=(local)\SQLExpress;Initial Catalog=yourdatabase.mdf;" _ 

& "Integrated Security;"

Option 3: You are using SQL Express and Database is not attached to server

Exmaple connection string

Dim conString As String

conString = "Data Source=(local)\SQLExpress;" _ 

& "AttachDbFilename=|DataDirectory|\yourdatabase.mdf;Integrated Security=true;"_ 

& "User Instance=true;"

ASP.NET Quiz

1. Explain the benefits of .NET framework in your own term?
2. What are the major components of .NET framework?
3. What is the role of Common Language Runtime (CLR)?
4. How do you relate asp with asp.net?
5. State the difference between these Html tags:

a)      <div id=”x1” runat=”server” ></div>

b)      <div id=”x1” ></div>

6. How a web server handles the following files (explain):

a)      first.html

b)      first.aspx

7. Compare and contrast server side and client side validation?
8. Validate an age input box, age should be in the range 25-35
9. Why rich controls are named so?
10. What is the use of MultiView control?

Ans: To break up a long data collection form (or any other related content) within the same page, use MultiView control. Read this article of mine about How to Use MultiView Control

11.  Validate the following text box: accept only alphabetic input <asp:TextBox id=”txt1” runat=”server” />
12. List and describe the types of Server controls.

Ans: We’ve two types of server controls in asp.net which are

13. How can you send a user to a new page in asp.net? Describe the different methods available and their differences.

Ans:

·         By using html anchor tag <a href=”page2.aspx”>Go to page 2</a>

·         By using asp.net hyperlink control <asp:HyperLink id=”hlk1” runat=”server” navigateUrl=”page2.aspx”>Go to page 2</asp:HyperLink>

·           For more please refer User Redirection article on this blog

14. Pages or web forms exchange data or information. How this happens? State at least one method and how to use it.

Ans:

·        QueryString

·         Session

·         Application

·        Cookies
etc

15. Http is stateless (i.e: page state is lost every time a page is posted back). How does asp.net overcome this fact?

Ans: By using a hidden control known as viewState which saves the contents of all controls in the page and bring back the content to the newly created page after postback.

16. Why do you think Html server controls are included in asp.net while we’ve got their powerful counterparts?

   Ans: For backward compatibility. If you have an already existing html page you can simply convert it into an asp.net web form by converting the html elements into html server controls.

17. List the benefits of using Master pages.

Ans:

·         Centralizes the look and feel of pages

·         Reduces code

·         Minimizes errors

·         Can be used to control access to pages

·         More about Master pages follow this link Master Pages
download doc

The ASP.NET MultiView Control

Have you ever wondered a way in which you can have a long form broken into wizards so that the user navigates step after step without placing contents in different files ?
Microsoft included an easy to use controls to solve this kind of problem. In fact, we can do this by using ordinary html server controls like using different  <div runat="server"></div> tags for different parts of our long form or <asp:Panel> just by making one panel visible and the rest invisible. But as we said Microsoft ASP.NET includes web controls especially designed for this purpose (MultiView and Wizard controls). Let us see how to use MultiView web control to divide a long form. Suppose you are developing registrar web portal for certain university, let us say University of Hargeisa (UoH). The student registration form of UoH is composed of at least three pages.Certainly you don't want to put this pages in different files if you can do this is some other way round.

Start:
Open your web developer (assuming that you've installed at least the free Web Developer Express edition)
if you don't have one go to this Microsoft official link and download it for free Visual Web Developer 2010 Express.
 Go to File>New Website, a default.aspx template page will be added to your new website.
 Go to Source view of the page, put your cursor in between the opening and closing tags of the form tag.
and type:

<asp:MultiView ID="MultiView1" runat="server">

   

</asp:MultiView>

Now you have added the MultiView web control but the different views(steps) not added yet so you may ask, what is the job of MultiView then ? It is purpose is just to keep the rule: no two views shall be visible at the same time, only one is allowed to be active. To add views we need to add another control known as View which serves as the step for our wizard. So put your cursor between the opening and closing tags of the above MultiView control and type three times of the following content:

 

<asp:View ID="View1" runat="server">

       

</asp:View>

Your  Mutliview with the Views should look like this:

<asp:MultiView ID="MultiView1" runat="server">

   

        <asp:View ID="View1" runat="server">       

        </asp:View>

       

        <asp:View ID="View2" runat="server">

        </asp:View>

       

        <asp:View ID="View3" runat="server">

        </asp:View>

  </asp:MultiView>

Now in between the opening and closing tags of each View add the contents of one of the pages of the registration form. For instance, Page 1 content should be added to View1. Finally, your code should be similar (this is a model and necessarily is not reflecting your code) to this:

<asp:MultiView ID="MultiView1" runat="server">

   

        <asp:View ID="View1" runat="server">       

           UoH Registration Form<br />

            &nbsp;Page 1 of 3<br />

            <br />

            <b>Personal Information</b><br />

            <br />

            First Name:

            <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

            <br />

            Last Name:

            <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>

            <br />

            <asp:Button ID="Button2" runat="server" CommandName="NextView"

                Text="Next &gt;" />

        </asp:View>

       

        <asp:View ID="View2" runat="server">

            Page 2 of 3<br />

            <br />

            <b>Educational Background</b><br />

            <br />

            Last Institution Name:

            <asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>

            <br />

            <asp:Button ID="Button3" runat="server" CommandName="PrevView"

                Text="&lt; Previous" />

            <asp:Button ID="Button4" runat="server" CommandName="NextView"

                Text="Next &gt;" />

        </asp:View>

       

        <asp:View ID="View3" runat="server">

            Page 3 of 3<br />

            <br />

            <asp:CheckBox ID="CheckBox1" runat="server"

                Text="I certify that the above information is correct " />

            <br />

            <asp:Button ID="Button5" runat="server" CommandName="PrevView"

                Text="&lt; Previous" />

            &nbsp;&nbsp;

            <asp:Button ID="Button6" runat="server" Text="Register Student" />

        </asp:View>

   

    </asp:MultiView>

 Now if you switch to the design view you would see the following design:

If you run your website at this point you will not be seeing any of these views. The reason is that MultiView control is not told yet which view to display by default. To do this set the ActiveViewIndex attribute of the MultiView control to 0 which means MultiView will be displaying the View with the index 0 at the first request of the page. After you add ActiveViewIndex attribute, the opening tag of the MultiView control should look like this:

 <asp:MultiView ID="MultiView1" runat="server" ActiveViewIndex="0">

Now you are ready to run your website, press F5 or go to the menu  Debug > Start Debugging, click Ok for the message box that appears. The result should be this:

Click the Next > button. Yes ! It takes you to the next view and so forth. What happened is an interesting phenomenon. You may have expected a code behind for the button to navigate us to the next level but this is not the case. So what is the magic around ? Go back to the code and take a look at the declarations of the buttons, you'll see a new attribute known as CommandName set to NextView for Next buttons and PrevView for the Previous buttons. Cool, isn't it ? This attribute is available for all button types (i.e: Buttons, ImageButtons, LinkButtons).