asp .net note

8/6/2019 ASP .Net Note

1/45

ASP.NET is the next generation ASP(Active server page), but it's not anupgraded version of ASP. ASP.NET is an entirely new technology for server-sidescripting.

ASP.NET is a part of the Microsoft .NET framework, and a powerful tool for

creating dynamic and interactive web pages

What You Should Already Know

Before you continue you should have a basic understanding of the following:

WWW, HTML, XML and the basics of building Web pages

Scripting languages like JavaScript or VBScript

The basics of server side scripting like ASP or PHP

If you want to study these subjects first, find the tutorials on our Home Page

What is Classic ASP?

Microsoft's previous server side scripting technology ASP (Active Server Pages) is now often calledclassic ASP.

ASP 3.0 was the last version of classic ASP.

To learn more about classic ASP, you can study our ASP tutorial.

ASP.NET is NOT ASP

ASP.NET is the next generation ASP, but it's not an upgraded version of ASP.

ASP.NET is an entirely new technology for server-side scripting. It was written from the ground up andis not backward compatible with classic ASP.

You can read more about the differences between ASP and ASP.NET in the next chapter of thistutorial.

ASP.NET is the major part of the Microsoft's .NET Framework.

What is ASP.NET?

ASP.NET is a server side scripting technology that enables scripts (embedded in web pages) to beexecuted by an Internet server.

ASP.NET is a Microsoft Technology

ASP stands for Active Server Pages

ASP.NET is a program that runs inside IIS

IIS (Internet Information Services) is Microsoft's Internet server

IIS comes as a free component with Windows servers

IIS is also a part of Windows 2000 and XP Professional

What is an ASP.NET File?

An ASP.NET file is just the same as an HTML file
http://www.w3schools.com/default.asphttp://www.w3schools.com/asp/default.asphttp://www.w3schools.com/asp/default.asphttp://www.w3schools.com/default.asp


2/45

An ASP.NET file can contain HTML, XML, and scripts

Scripts in an ASP.NET file are executed on the server

An ASP.NET file has the file extension ".aspx"

How Does ASP.NET Work?

When a browser requests an HTML file, the server returns the file

When a browser requests an ASP.NET file, IIS passes the request to the ASP.NET engine onthe server

The ASP.NET engine reads the file, line by line, and executes the scripts in the file

Finally, the ASP.NET file is returned to the browser as plain HTML

What is ASP+?

ASP+ is the same as ASP.NET.

ASP+ is just an early name used by Microsoft when they developed ASP.NET.

The Microsoft .NET Framework

The .NET Framework is the infrastructure for the Microsoft .NET platform.

The .NET Framework is an environment for building, deploying, and running Web applications and WebServices.

Microsoft's first server technology ASP (Active Server Pages), was a powerful and flexible"programming language". But it was too code oriented. It was not an application framework and notan enterprise development tool.

The Microsoft .NET Framework was developed to solve this problem.

.NET Frameworks keywords:

Easier and quicker programming

Reduced amount of code

Declarative programming model

Richer server control hierarchy with events

Larger class library

Better support for development tools

The .NET Framework consists of 3 main parts:

Programming languages:

C# (Pronounced C sharp)

Visual Basic (VB .NET)

J# (Pronounced J sharp)

Server technologies and client technologies:

ASP .NET (Active Server Pages)

Windows Forms (Windows desktop solutions)

Compact Framework (PDA / Mobile solutions)


3/45

Development environments:

Visual Studio .NET (VS .NET)

Visual Web Developer

This tutorial is about ASP.NET.

ASP.NET 2.0

ASP.NET 2.0 improves upon ASP.NET by adding support for several new features.

You can read more about the differences between ASP.NET 2.0 and ASP.NET in the next chapter ofthis tutorial.

ASP.NET 3.0

ASP.NET 3.0 is not a new version of ASP.NET. It's just the name for a new ASP.NET 2.0 frameworklibrary with support for Windows Presentation Foundation, Windows Communication Foundation,Windows Workflow Foundation; and Windows CardSpace.

Asp.net vs ASP

ASP.NET has better language support, a large set of new controls, XML-based

components, and better user authentication.

ASP.NET provides increased performance by running compiled code.

ASP.NET code is not fully backward compatible with ASP.

New in ASP.NET

Better language support

Programmable controls

Event-driven programming

XML-based components

User authentication, with accounts and roles

Higher scalability

Increased performance - Compiled code

Easier configuration and deployment

Not fully ASP compatible

Language Support

ASP.NET uses ADO.NET.

ASP.NET supports full Visual Basic, not VBScript.

ASP.NET supports C# (C sharp) and C++.

ASP.NET supports JScript.


4/45

ASP.NET Controls

ASP.NET contains a large set of HTML controls. Almost all HTML elements on a page can be defined asASP.NET control objects that can be controlled by scripts.

ASP.NET also contains a new set of object-oriented input controls, like programmable list-boxes andvalidation controls.

A new data grid control supports sorting, data paging, and everything you can expect from a datasetcontrol.

Event Aware Controls

All ASP.NET objects on a Web page can expose events that can be processed by ASP.NET code.

Load, Click and Change events handled by code makes coding much simpler and much betterorganized.

ASP.NET Components

ASP.NET components are heavily based on XML. Like the new AD Rotator, that uses XML to storeadvertisement information and configuration.

User Authentication

ASP.NET supports form-based user authentication, cookie management, and automatic redirecting ofunauthorized logins.

User Accounts and Roles

ASP.NET allows user accounts and roles, to give each user (with a given role) access to differentserver code and executables.

High Scalability

Much has been done with ASP.NET to provide greater scalability.

Server-to-server communication has been greatly enhanced, making it possible to scale an applicationover several servers. One example of this is the ability to run XML parsers, XSL transformations andeven resource hungry session objects on other servers.

Compiled Code

The first request for an ASP.NET page on the server will compile the ASP.NET code and keep a cachedcopy in memory. The result of this is greatly increased performance.

Easy Configuration

Configuration of ASP.NET is done with plain text files.


5/45

Configuration files can be uploaded or changed while the application is running. No need to restart theserver. No more metabase or registry puzzle.

Easy Deployment

No more server-restart to deploy or replace compiled code. ASP.NET simply redirects all new requeststo the new code.

Compatibility

ASP.NET is not fully compatible with earlier versions of ASP, so most of the old ASP code will needsome changes to run under ASP.NET.

To overcome this problem, ASP.NET uses a new file extension ".aspx". This will make ASP.NETapplications able to run side by side with standard ASP applications on the same server.

ASP.NET Installing

ASP.NET is easy to install. Just follow the instructions below.

What You Need

If you have a Beta version of ASP.NET installed, we recommend that you completely uninstall it!

Or even better: start with a fresh Windows 2000 or XP installation!

Windows 2000 or XP

If you are serious about developing ASP.NET applications you should install Windows 2000Professional or Windows XP Professional.

In both cases, install the Internet Information Services (IIS) from the Add/Remove Windowscomponents dialog.

Service Packs and Updates

Before ASP.NET can be installed on your computer, all relevant service packs and security updatesmust be installed.

The easiest way to do this is to activate your Windows Internet Update. When you access the Windows

Update page, you will be instructed to install the latest service packs and all critical security updates.For Windows 2000, make sure you install Service Pack 2. You should also install the latest version ofInternet Explorer.

Tip: Read the note about connection speed and download time at the bottom of this page.

Install .NET

From your Windows Update you can now select the Microsoft .NET Framework.


6/45

After download, the .NET framework will install itself on your computer - there are no options to selectfor installation.

You are now ready to develop your first ASP.NET application!

The .NET Software Development KitIf you have the necessary bandwidth, you might consider downloading the full Microsoft .NET SoftwareDevelopment Kit (SDK).

We fully recommend getting the SDK for learning more about .NET, and for the documentation,samples, and tools included.

A simple ASP.NET page looks just like an ordinary HTML page.

Hello India

To start learning ASP.NET, we will construct a very simple HTML page that will display "Hello India" inan Internet browser like this:

Hello India !

Hello India in HTML

This code displays the example as an HTML page:

Hello India !

If you want to try it yourself, save the code in a file called "firstpage.htm", and create a link to thefile like this: firstpage.htm

Hello India in ASP.NET

The simplest way to convert an HTML page into an ASP.NET page is to copy the HTML file to a new filewith an .aspx extension.

This code displays our example as an ASP.NET page:

Hello India !
http://www.w3schools.com/aspnet/firstpage.htmhttp://www.w3schools.com/aspnet/firstpage.htm


7/45

If you want to try it yourself, save the code in a file called "firstpage.aspx", and create a link to thefile like this: firstpage.aspx

How Does it Work?

Fundamentally an ASP.NET page is just the same as an HTML page.

An HTML page has the extension .htm. If a browser requests an HTML page from the server, theserver sends the page to the browser without any modifications.

An ASP.NET page has the extension .aspx. If a browser requests an ASP.NET page, the serverprocesses any executable code in the page, before the result is sent back to the browser.

The ASP.NET page above does not contain any executable code, so nothing is executed. In the nextexamples we will add some executable code to the page to demonstrate the difference between staticHTML pages and dynamic ASP pages.

Classic ASP

Active Server Pages (ASP) has been around for several years. With ASP, executable code can be

placed inside HTML pages.

Previous versions of ASP (before ASP .NET) are often called Classic ASP.

ASP.NET is not fully compatible with Classic ASP, but most Classic ASP pages will work fine asASP.NET pages, with only minor changes.

If you want to learn more about Classic ASP, please visit our ASP Tutorial.

Dynamic Page in Classic ASP

To demonstrate how ASP can display pages with dynamic content, we have added some executablecode (in red) to the previous example:

Hello India!

The code inside the tags is executed on the server.

Response.Write is ASP code for writing something to the HTML output stream.

Now() is a function returning the servers current date and time.

If you want to try it yourself, save the code in a file called "dynpage.asp", and create a link to the filelike this: dynpage.asp
http://www.w3schools.com/aspnet/firstpage.aspxhttp://www.w3schools.com/asp/default.asphttp://www.w3schools.com/aspnet/dynpage.asphttp://www.w3schools.com/aspnet/firstpage.aspxhttp://www.w3schools.com/asp/default.asphttp://www.w3schools.com/aspnet/dynpage.asp


8/45

Dynamic Page in ASP .NET

This following code displays our example as an ASP.NET page:

Hello India!

If you want to try it yourself, save the code in a file called "dynpage.aspx", and create a link to thefile like this: dynpage.aspx

ASP.NET vs Classic ASP

The previous examples didn't demonstrate any differences between ASP.NET and Classic ASP.

As you can see from the two latest examples there are no differences between the two ASP andASP.NET pages.

In the next chapters you will see how server controls make ASP.NET more powerful than Classic ASP.

Server controls are tags that are understood by the server.

Limitations in Classic ASP

The listing below was copied from the previous chapter:

Hello India!

The code above illustrates a limitation in Classic ASP: The code block has to be placed where you wantthe output to appear.

With Classic ASP it is impossible to separate executable code from the HTML itself. This makes thepage difficult to read, and difficult to maintain.

ASP.NET - Server Controls

ASP.NET has solved the "spaghetti-code" problem described above with server controls.

Server controls are tags that are understood by the server.

There are three kinds of server controls:

HTML Server Controls - Traditional HTML tags

Web Server Controls - New ASP.NET tags
http://www.w3schools.com/aspnet/dynpage.aspxhttp://www.w3schools.com/aspnet/dynpage.aspx


9/45

Validation Server Controls - For input validation

ASP.NET - HTML Server Controls

HTML server controls are HTML tags understood by the server.

HTML elements in ASP.NET files are, by default, treated as text. To make these elementsprogrammable, add a runat="server" attribute to the HTML element. This attribute indicates that theelement should be treated as a server control. The id attribute is added to identify the server control.The id reference can be used to manipulate the server control at run time.

Note: All HTML server controls must be within a tag with the runat="server" attribute. Therunat="server" attribute indicates that the form should be processed on the server. It also indicatesthat the enclosed controls can be accessed by server scripts.

In the following example we declare an HtmlAnchor server control in an .aspx file. Then wemanipulate the HRef attribute of the HtmlAnchor control in an event handler (an event handler is asubroutine that executes code for a given event). The Page_Load event is one of many events thatASP.NET understands:

Sub Page_Loadlink1.HRef="http://www.India.com"End Sub

Visit India!

The executable code itself has been moved outside the HTML.

ASP.NET - Web Server Controls

Web server controls are special ASP.NET tags understood by the server.

Like HTML server controls, Web server controls are also created on the server and they require arunat="server" attribute to work. However, Web server controls do not necessarily map to anyexisting HTML elements and they may represent more complex elements.

The syntax for creating a Web server control is:

In the following example we declare a Button server control in an .aspx file. Then we create an eventhandler for the Click event which changes the text on the button:

Sub submit(Source As Object, e As EventArgs)button1.Text="You clicked me!"End Sub


10/45

ASP.NET - Validation Server Controls

Validation server controls are used to validate user-input. If the user-input does not pass validation, itwill display an error message to the user.

Each validation control performs a specific type of validation (like validating against a specific value ora range of values).

By default, page validation is performed when a Button, ImageButton, or LinkButton control is clicked.You can prevent validation when a button control is clicked by setting the CausesValidation property tofalse.

The syntax for creating a Validation server control is:

In the following example we declare one TextBox control, one Button control, and one RangeValidatorcontrol in an .aspx file. If validation fails, the text "The value must be from 1 to 100!" will be displayedin the RangeValidator control:

Example

Enter a number from 1 to 100:


11/45

An Event Handler is a subroutine that executes code for a given event.

ASP.NET - Event Handlers

Look at the following code:

When will the code above be executed? The answer is: "You don't know..."

The Page_Load Event

The Page_Load event is one of many events that ASP.NET understands. The Page_Load event istriggered when a page loads, and ASP.NET will automatically call the subroutine Page_Load, andexecute the code inside it:

Example

Sub Page_Loadlbl1.Text="The date and time is " & now()End Sub

Note: The Page_Load event contains no object references or event arguments!


12/45

The Page.IsPostBack Property

The Page_Load subroutine runs EVERY time the page is loaded. If you want to execute the code in thePage_Load subroutine only the FIRST time the page is loaded, you can use the Page.IsPostBackproperty. If the Page.IsPostBack property is false, the page is loaded for the first time, if it is true, thepage is posted back to the server (i.e. from a button click on a form):

Example

Sub Page_Loadif Not Page.IsPostBack thenlbl1.Text="The date and time is " & now()

end ifEnd Sub

Sub submit(s As Object, e As EventArgs)lbl2.Text="Hello World!"End Sub

All server controls must appear within a tag, and the tag must contain

the runat="server" attribute.

ASP.NET Web Forms

All server controls must appear within a tag, and the tag must contain therunat="server" attribute. The runat="server" attribute indicates that the form should be processed onthe server. It also indicates that the enclosed controls can be accessed by server scripts:

...HTML + server controls

Note: The form is always submitted to the page itself. If you specify an action attribute, it is ignored.If you omit the method attribute, it will be set to method="post" by default. Also, if you do not specifythe name and id attributes, they are automatically assigned by ASP.NET.

Note: An .aspx page can only contain ONE control!


13/45

If you select view source in an .aspx page containing a form with no name, method, action, or idattribute specified, you will see that ASP.NET has added these attributes to the form. It lookssomething like this:

...some code

Submitting a Form

A form is most often submitted by clicking on a button. The Button server control in ASP.NET has thefollowing format:

The id attribute defines a unique name for the button and the text attribute assigns a label to thebutton. The onClick event handler specifies a named subroutine to execute.

In the following example we declare a Button control in an .aspx file. A button click runs a subroutinewhich changes the text on the button:

You may save a lot of coding by maintaining the ViewState of the objects in your WebForm.

Maintaining the ViewState

When a form is submitted in classic ASP, all form values are cleared. Suppose you have submitted a

form with a lot of information and the server comes back with an error. You will have to go back to theform and correct the information. You click the back button, and what happens.......ALL form valuesare CLEARED, and you will have to start all over again! The site did not maintain your ViewState.

When a form is submitted in ASP .NET, the form reappears in the browser window together with allform values. How come? This is because ASP .NET maintains your ViewState. The ViewState indicatesthe status of the page when submitted to the server. The status is defined through a hidden fieldplaced on each page with a control. The source could look something like this:

.....some code

Maintaining the ViewState is the default setting for ASP.NET Web Forms. If you want to NOT maintainthe ViewState, include the directive at the top of an .aspxpage or add the attribute EnableViewState="false" to any control.

Look at the following .aspx file. It demonstrates the "old" way to do it. When you click on the submitbutton, the form value will disappear:


14/45

Example

Your name:

Here is the new ASP .NET way. When you click on the submit button, the form value will NOTdisappear:

Example

Click view source in the right frame of the example to see that ASP .NET has added a hidden fieldin the form to maintain the ViewState

Sub submit(sender As Object, e As EventArgs)lbl1.Text="Hello " & txt1.Text & "!"End Sub

Your name:

The TextBox control is used to create a text box where the user can input text.

The TextBox Control

The TextBox control is used to create a text box where the user can input text.

The TextBox control's attributes and properties are listed in our web controls reference page.
http://www.w3schools.com/aspnet/aspnet_refwebcontrols.asphttp://www.w3schools.com/aspnet/aspnet_refwebcontrols.asp


15/45

The example below demonstrates some of the attributes you may use with the TextBox control:

Example

A basic TextBox:

A password TextBox:

A TextBox with text:

A multiline TextBox:

A TextBox with height:

A TextBox with width:

Show example

Add a Script

The contents and settings of a TextBox control may be changed by server scripts when a form issubmitted. A form can be submitted by clicking on a button or when a user changes the value in the

TextBox control.In the following example we declare one TextBox control, one Button control, and one Label control inan .aspx file. When the submit button is triggered, the submit subroutine is executed. The submitsubroutine writes a text to the Label control:

Example

Sub submit(sender As Object, e As EventArgs)
http://www.w3schools.com/aspnet/showasp.asp?filename=demo_textbox_ex1http://www.w3schools.com/aspnet/showasp.asp?filename=demo_textbox_ex1


16/45

lbl1.Text="Your name is " & txt1.TextEnd Sub

Enter your name:

In the following example we declare one TextBox control and one Label control in an .aspx file. Whenyou change the value in the TextBox and either click outside the TextBox or press the Tab key, thechange subroutine is executed. The submit subroutine writes a text to the Label control:

Example

Sub change(sender As Object, e As EventArgs)lbl1.Text="You changed text to " & txt1.TextEnd Sub

Enter your name:

The Button control is used to display a push button.

The Button Control


17/45

The Button control is used to display a push button. The push button may be a submit button or acommand button. By default, this control is a submit button.

A submit button does not have a command name and it posts the page back to the server when it isclicked. It is possible to write an event handler to control the actions performed when the submitbutton is clicked.

A command button has a command name and allows you to create multiple Button controls on a page.

It is possible to write an event handler to control the actions performed when the command button isclicked.

The Button control's attributes and properties are listed in our web controls reference page.

The example below demonstrates a simple Button control:

Add a Script

A form is most often submitted by clicking on a button.

In the following example we declare one TextBox control, one Button control, and one Label control inan .aspx file. When the submit button is triggered, the submit subroutine is executed. The submitsubroutine writes a text to the Label control:

ExampleSub submit(sender As Object, e As EventArgs)lbl1.Text="Your name is " & txt1.TextEnd Sub

Enter your name:
http://www.w3schools.com/aspnet/aspnet_refwebcontrols.asphttp://www.w3schools.com/aspnet/aspnet_refwebcontrols.asp


18/45

We may use data binding to fill lists with selectable items from an imported datasource, like a database, an XML file, or a script.

Data BindingThe following controls are list controls which support data binding:

asp:RadioButtonList

asp:CheckBoxList

asp:DropDownList

asp:Listbox

The selectable items in each of the above controls are usually defined by one or more asp:ListItemcontrols, like this:

However, with data binding we may use a separate source, like a database, an XML file, or a script tofill the list with selectable items.

By using an imported source, the data is separated from the HTML, and any changes to the items are

made in the separate data source.

In the next three chapters, we will describe how to bind data from a scripted data source.

ArrayList

The ArrayList object is a collection of items containing a single data value.

Create an ArrayList

The ArrayList object is a collection of items containing a single data value.Items are added to the ArrayList with the Add() method.

The following code creates a new ArrayList object named mycountries and four items are added:

Sub Page_Loadif Not Page.IsPostBack thendim mycountries=New ArrayListmycountries.Add("Norway")


19/45

mycountries.Add("Sweden")mycountries.Add("France")mycountries.Add("Italy")

end ifend sub

By default, an ArrayList object contains 16 entries. An ArrayList can be sized to its final size with theTrimToSize() method:

Sub Page_Loadif Not Page.IsPostBack thendim mycountries=New ArrayListmycountries.Add("Norway")mycountries.Add("Sweden")mycountries.Add("France")mycountries.Add("Italy")mycountries.TrimToSize()

end if

end sub

An ArrayList can also be sorted alphabetically or numerically with the Sort() method:

Sub Page_Loadif Not Page.IsPostBack thendim mycountries=New ArrayListmycountries.Add("Norway")mycountries.Add("Sweden")mycountries.Add("France")mycountries.Add("Italy")

mycountries.TrimToSize()mycountries.Sort()

end ifend sub

To sort in reverse order, apply the Reverse() method after the Sort() method:

Sub Page_Loadif Not Page.IsPostBack thendim mycountries=New ArrayListmycountries.Add("Norway")mycountries.Add("Sweden")mycountries.Add("France")mycountries.Add("Italy")mycountries.TrimToSize()mycountries.Sort()mycountries.Reverse()

end ifend sub


20/45

Data Binding to an ArrayList

An ArrayList object may automatically generate the text and values to the following controls:

asp:RadioButtonList

asp:CheckBoxList

asp:DropDownList

asp:Listbox

To bind data to a RadioButtonList control, first create a RadioButtonList control (without anyasp:ListItem elements) in an .aspx page:

Then add the script that builds the list and binds the values in the list to the RadioButtonList control:

Example

Sub Page_Loadif Not Page.IsPostBack thendim mycountries=New ArrayList

mycountries.Add("Norway")mycountries.Add("Sweden")mycountries.Add("France")mycountries.Add("Italy")mycountries.TrimToSize()mycountries.Sort()rb.DataSource=mycountriesrb.DataBind()

end ifend sub


21/45

The DataSource property of the RadioButtonList control is set to the ArrayList and it defines the datasource of the RadioButtonList control. The DataBind() method of the RadioButtonList control binds thedata source with the RadioButtonList control.

Note: The data values are used as both the Text and Value properties for the control. To add Values

that are different from the Text, use either the Hashtable object or the SortedList object.

HashtableThe Hashtable object contains items in key/value pairs.

Create a Hashtable

The Hashtable object contains items in key/value pairs. The keys are used as indexes, and very quicksearches can be made for values by searching through their keys.

Items are added to the Hashtable with the Add() method.

The following code creates a Hashtable named mycountries and four elements are added:

Sub Page_Loadif Not Page.IsPostBack thendim mycountries=New Hashtablemycountries.Add("N","Norway")mycountries.Add("S","Sweden")mycountries.Add("F","France")mycountries.Add("I","Italy")

end ifend sub

Data Binding

A Hashtable object may automatically generate the text and values to the following controls:

asp:RadioButtonList

asp:CheckBoxList

asp:DropDownList

asp:Listbox



22/45

Then add the script that builds the list:

sub Page_Loadif Not Page.IsPostBack thendim mycountries=New Hashtablemycountries.Add("N","Norway")mycountries.Add("S","Sweden")mycountries.Add("F","France")mycountries.Add("I","Italy")rb.DataSource=mycountriesrb.DataValueField="Key"rb.DataTextField="Value"rb.DataBind()

end ifend sub

Then we add a sub routine to be executed when the user clicks on an item in the RadioButtonListcontrol. When a radio button is clicked, a text will appear in a label:

Example

sub Page_Loadif Not Page.IsPostBack thendim mycountries=New Hashtablemycountries.Add("N","Norway")mycountries.Add("S","Sweden")mycountries.Add("F","France")mycountries.Add("I","Italy")rb.DataSource=mycountriesrb.DataValueField="Key"

rb.DataTextField="Value"rb.DataBind()end ifend sub

sub displayMessage(s as Object,e As EventArgs)lbl1.text="Your favorite country is: " & rb.SelectedItem.Textend sub


23/45

Output of this program

Norway

Italy

Sweden

France

Your favorite country is: France

ASP.NET The SortedList Object

The SortedList object combines the features of both the ArrayList object and the

Hashtable object.

The SortedList Object

The SortedList object contains items in key/value pairs. A SortedList object automatically sort theitems in alphabetic or numeric order.

Items are added to the SortedList with the Add() method. A SortedList can be sized to its final sizewith the TrimToSize() method.


24/45

The following code creates a SortedList named mycountries and four elements are added:

sub Page_Load

if Not Page.IsPostBack then

dim mycountries=New SortedList

mycountries.Add("N","Norway")mycountries.Add("S","Sweden")

mycountries.Add("F","France")

mycountries.Add("I","Italy")

end if

end sub

Data Binding

A SortedList object may automatically generate the text and values to the following controls:

asp:RadioButtonList

asp:CheckBoxList

asp:DropDownList

asp:Listbox


Then add the script that builds the list:

sub Page_Load



mycountries.Add("N","Norway")

mycountries.Add("S","Sweden")



rb.DataSource=mycountries

rb.DataValueField="Key"

rb.DataTextField="Value"


25/45

rb.DataBind()

end if

end sub


Example

sub Page_Load



mycountries.Add("N","Norway")

mycountries.Add("S","Sweden")




rb.DataValueField="Key"

rb.DataTextField="Value"

rb.DataBind()

end if

end sub

sub displayMessage(s as Object,e As EventArgs)

lbl1.text="Your favorite country is: " & rb.SelectedItem.Text

end sub


26/45

ASP .NET - XML Files

We can bind an XML file to a list control.

An XML File

Here is an XML file named "countries.xml":

Norway

N

Sweden

S

France

F

Italy

I

Bind a DataSet to a List Control

First, import the "System.Data" namespace. We need this namespace to work with DataSet objects.Include the following directive at the top of an .aspx page:


27/45

Next, create a DataSet for the XML file and load the XML file into the DataSet when the page is firstloaded:

sub Page_Load


dim mycountries=New DataSetmycountries.ReadXml(MapPath("countries.xml"))

end if

end sub

To bind the DataSet to a RadioButtonList control, first create a RadioButtonList control (without anyasp:ListItem elements) in an .aspx page:

Then add the script that builds the XML DataSet:

sub Page_Load


dim mycountries=New DataSetmycountries.ReadXml(MapPath("countries.xml"))


rb.DataValueField="value"

rb.DataTextField="text"

rb.DataBind()

end if

end sub


28/45


Example

sub Page_Load


dim mycountries=New DataSet

mycountries.ReadXml(MapPath("countries.xml"))


rb.DataValueField="value"

rb.DataTextField="text"

rb.DataBind()

end ifend sub

sub displayMessage(s as Object,e As EventArgs)

lbl1.text="Your favorite country is: " & rb.SelectedItem.Text

end sub

ASP.NET - The Repeater Control

The Repeater control is used to display a repeated list of items that are bound to thecontrol.

Bind a DataSet to a Repeater Control


29/45

The Repeater control is used to display a repeated list of items that are bound to the control. TheRepeater control may be bound to a database table, an XML file, or another list of items. Here we willshow how to bind an XML file to a Repeater control.

We will use the following XML file in our examples ("cdcatalog.xml"):

Empire Burlesque

Bob Dylan

USA

Columbia

10.90

1985

Hide your heart

Bonnie TylerUK

CBS Records

9.90

1988

Greatest Hits

Dolly Parton

USA

RCA

9.90

1982

Still got the blues

Gary Moore

UK

Virgin records

10.20

1990

ErosEros Ramazzotti

EU

BMG

9.90

1997


30/45

Take a look at the XML file: cdcatalog.xml

First, import the "System.Data" namespace. We need this namespace to work with DataSet objects.Include the following directive at the top of an .aspx page:

Next, create a DataSet for the XML file and load the XML file into the DataSet when the page is firstloaded:

sub Page_Load


dim mycdcatalog=New DataSet

mycdcatalog.ReadXml(MapPath("cdcatalog.xml"))

end if

end sub

Then we create a Repeater control in an .aspx page. The contents of the elementare rendered first and only once within the output, then the contents of the elementare repeated for each "record" in the DataSet, and last, the contents of the element are rendered once within the output:

...

...

...

Then we add the script that creates the DataSet and binds the mycdcatalog DataSet to the Repeatercontrol. We also fill the Repeater control with HTML tags and bind the data items to the cells in

the section with the method:

Example
http://www.w3schools.com/aspnet/cdcatalog.xmlhttp://www.w3schools.com/aspnet/cdcatalog.xml


31/45

sub Page_Load


dim mycdcatalog=New DataSetmycdcatalog.ReadXml(MapPath("cdcatalog.xml"))

cdcatalog.DataSource=mycdcatalog

cdcatalog.DataBind()

end if

end sub

Title

Artist

Country

Company

Price

Year


32/45

Using the

You can add an element after the element to describethe appearance of alternating rows of output. In the following example each other row in the table willbe displayed in a light grey color:

Example

sub Page_Load

if Not Page.IsPostBack thendim mycdcatalog=New DataSet




end if

end sub

Title

Artist

Country

Company

Price

Year


33/45

Using the

The element can be used to describe a separator between each record. Thefollowing example inserts a horizontal line between each table row:

Example

sub Page_Load

if Not Page.IsPostBack thendim mycdcatalog=New DataSet




end if

end sub


34/45

Title

Artist

Country

Company

Price

Year


35/45

ASP.NET - Database Connection

ADO.NET is also a part of the .NET Framework. ADO.NET is used to handle data access.With ADO.NET you can work with databases.

What is ADO.NET?

ADO.NET is a part of the .NET Framework

ADO.NET consists of a set of classes used to handle data access

ADO.NET is entirely based on XML

ADO.NET has, unlike ADO, no Recordset object

Create a Database Connection

We are going to use the Northwind database in our examples.

First, import the "System.Data.OleDb" namespace. We need this namespace to work with MicrosoftAccess and other OLE DB database providers. We will create the connection to the database in thePage_Load subroutine. We create a dbconn variable as a new OleDbConnection class with aconnection string which identifies the OLE DB provider and the location of the database. Then we openthe database connection:

sub Page_Loaddim dbconn

dbconn=New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;

data source=" & server.mappath("northwind.mdb"))

dbconn.Open()

end sub

Note: The connection string must be a continuous string without a line break!

Create a Database Command

To specify the records to retrieve from the database, we will create a dbcomm variable as a newOleDbCommand class. The OleDbCommand class is for issuing SQL queries against database tables:

sub Page_Load

dim dbconn,sql,dbcomm


36/45



dbconn.Open()

sql="SELECT * FROM customers"

dbcomm=New OleDbCommand(sql,dbconn)

end sub

Create a DataReader

The OleDbDataReader class is used to read a stream of records from a data source. A DataReader iscreated by calling the ExecuteReader method of the OleDbCommand object:

sub Page_Load

dim dbconn,sql,dbcomm,dbread



dbconn.Open()



dbread=dbcomm.ExecuteReader()

end sub

Bind to a Repeater Control

Then we bind the DataReader to a Repeater control:

Example

sub Page_Load

dim dbconn,sql,dbcomm,dbreaddbconn=New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;


dbconn.Open()



dbread=dbcomm.ExecuteReader()

customers.DataSource=dbread


37/45

customers.DataBind()

dbread.Close()

dbconn.Close()

end sub

Companyname

Contactname

Address

City

Close the Database Connection

Always close both the DataReader and database connection after access to the database is no longerrequired:

dbread.Close()


38/45

dbconn.Close()

ASP.NET 2.0 - New Features

ASP.NET 2.0 improves ASP.NET by adding several new features.

Improvements in ASP.NET 2.0

ASP.NET 2.0 was designed to make web development easier and quicker.

Design goals for ASP.NET 2.0:

Increase productivity by removing 70% of the code

Use the same controls for all types of devices

Provide a faster and better web server platform

Simplify compilation and installation

Simplify the administration of web applications

What's New in ASP.NET 2.0?

Some of the new features in ASP.NET 2.0 are:

Master Pages, Themes, and Web Parts

Standard controls for navigation

Standard controls for security

Roles, personalization, and internationalization services

Improved and simplified data access controls

Full support for XML standards like, XHTML, XML, and WSDL

Improved compilation and deployment (installation)

Improved site management

New and improved development tools

The new features are described below.

Master Pages

ASP.NET didn't have a method for applying a consistent look and feel for a whole web site.

Master pages in ASP.NET 2.0 solves this problem.


39/45

A master page is a template for other pages, with shared layout and functionality. The master pagedefines placeholders for content pages. The result page is a combination (merge) of the master pageand the content page.

Read more about master pages.

ThemesThemes is another feature of ASP.NET 2.0. Themes, or skins, allow developers to create a customizedlook for web applications.

Design goals for ASP.NET 2.0 themes:

Make it simple to customize the appearance of a site

Allow themes to be applied to controls, pages, and entire sites

Allow all visual elements to be customized

Web Parts

ASP.NET 2.0 Web Parts can provide a consistent look for a site, while still allowing user customizationof style and content.

New controls:

Zone controls - areas on a page where the content is consistent

Web part controls - content areas for each zone

Navigation

ASP.NET 2.0 has built-in navigation controls like

Site Maps

Dynamic HTML menus

Tree Views

Security

Security is very important for protecting confidential and personal information.

In ASP.NET 2.0 the following controls has been added:

A Login control, which provides login functionality

A LoginStatus control, to control the login status

A LoginName control to display the current user name

A LoginView control, to provide different views depending on login status

A CreateUser wizard, to allow creation of user accounts

A PasswordRecovery control, to provide the "I forgot my password" functionality

Roles and Personalization
http://www.w3schools.com/aspnet/aspnet_masterpages.asphttp://www.w3schools.com/aspnet/aspnet_masterpages.asp


40/45

Internet communities are growing very popular.

ASP.NET 2.0 has personalization features for storing user details. This provides an easy way tocustomize user (and user group) properties.

InternationalizationReaching people with different languages is important if you want to reach a larger audience.

ASP.NET 2.0 has improved support for multiple languages.

Data Access

Many web sites are data driven, using databases or XML files as data sources.

With ASP.NET this involved code, and often the same code had to be used over and over in differentweb pages.

A key goal of ASP.NET 2.0 was to ease the use of data sources.

ASP.NET 2.0 has new data controls, removing much of the need for programming and in-depthknowledge of data connections.

Mobility Support

The problem with Mobile devices is screen size and display capabilities.

In ASP.NET, the Microsoft Mobile Internet Toolkit (MMIT) provided this support.

In ASP.NET 2.0, MMIT is no longer needed because mobile support is built into all controls.

ImagesASP.NET 2.0 has new controls for handling images:

The ImageMap control - image map support

The DynamicImage control - image support for different browsers

These controls are important for better image display on mobile devices, like hand-held computersand cell phones.

Automatic Compilation

ASP.NET 2.0 provides automatic compilation. All files within a directory will be compiled on the firstrun, including support for WSDL, and XSD files.

Compiled Deployment (Installation) and Source Protection

ASP.NET 2.0 also provides pre-compilation. An entire web site can be pre-compiled. This provides aneasy way to deploy (upload to a server) compiled applications, and because only compiled files aredeployed, the source code is protected.


41/45

Site Management

ASP.NET 2.0 has three new features for web site configuration and management:

New local management console

New programmable management functions (API)

New web-based management tool

Development Tools

With ASP.NET Visual Studio.NET was released with project and design features targeted at corporatedevelopers.

With ASP.NET 2.0, Visual Studio 2005 was released.

Key design features for Visual Studio 2005 include:

Support for the features described above

Upload files from anywhere (FTP, File System, Front Page....)

No project files, allowing code to be manipulated outside Visual Studio

Integrated Web Site Administration Tool

No "build" step - ability to compile on first run

Visual Web Developer is a new free ASP.NET 2.0 tool for non-corporate developers who don't haveaccess to Visual Studio.NET.

ASP.NET 2.0 - Master Pages

Master pages provide templates for other pages on your web site.

Master Pages

Master pages allow you to create a consistent look and behavior for all the pages (or group of pages)

in your web application.

A master page provides a template for other pages, with shared layout and functionality. The masterpage defines placeholders for the content, which can be overridden by content pages. The output

result is a combination of the master page and the content page.

The content pages contains the content you want to display.

When users request the content page, ASP.NET merges the pages to produce output that combinesthe layout of the master page with the content of the content page.

Master Page Example


42/45

Standard Header For All Pages

The master page above is a normal HTML page designed as a template for other pages.

The @ Master directive defines it as a master page.

The master page contains a placeholder tag for individual content.

The id="CPH1" attribute identifies the placeholder, allowing many placeholders in the same masterpage.

This master page was saved with the name "master1.master".

Note: The master page can also contain code, allowing dynamic content.

Content Page Example

Individual Content

Paragraph 1

Paragraph 2

The content page above is one of the individual content pages of the web.

The @ Page directive defines it as a standard content page.

The content page contains a content tag with a reference to the master page(ContentPlaceHolderId="CPH1").

This content page was saved with the name "mypage1.aspx".

When the user requests this page, ASP.NET merges the content page with the master page.

Note: The content text must be inside the tag. No content is allowed outside the

tag.

Content Page With Controls

India


43/45

The content page above demonstrates how .NET controls can be inserted into the content page justlike an into an ordinary page.

ASP.NET 2.0 - Navigation

ASP.NET 2.0 has built-in navigation controls

Web Site NavigationMaintaining the menu of a large web site is difficult and time consuming.

In ASP.NET 2.0 the menu can be stored in a file to make it easier to maintain. This file is normallycalled web.sitemap, and is stored in the root directory of the web.

In addition, ASP.NET 2.0 has three new navigation controls:

Dynamic menus

TreeViews

Site Map Path

The Sitemap FileThe following sitemap file is used in this tutorial:

Rules for creating a sitemap file:

The XML file must contain a tag surrounding the content

The tag can only have one child node (the "home" page)

Each can have several child nodes (web pages)

Each has attributes defining page title and URL


44/45

Note: The sitemap file must be placed in the root directory of the web and the URL attributes mustbe relative to the root directory.

Dynamic Menu

The control displays a standard site navigation menu.

Code Example:

The control in the example above is a placeholder for a server created navigationmenu.

The data source of the control is defined by the DataSourceId attribute. The id="nav1" connects itto the control.

The control automatically connects to the default sitemap file(web.sitemap).

TreeView

The control displays a multi level navigation menu.

The menu looks like a tree with branches that can be opened or closed with + or - symbol.

Code Example:

The control in the example above is a placeholder for a server created navigationmenu.

The data source of the control is defined by the DataSourceId attribute. The id="nav1" connects itto the control.

The control automatically connects to the default sitemap file(web.sitemap).

SiteMapPath

The SiteMapPath control displays the trail (navigation path) to the current page. The path acts asclickable links to previous pages.

Unlike the TreeView and Menu control the SiteMapPath control does NOT use a SiteMapDataSource.The SiteMapPath control uses the web.sitemap file by default.


45/45

Tips: If the SiteMapPath displays incorrectly, most likely there is an URL error (typo) in theweb.sitemap file.

Code Example:

The control in the example above is a placeholder for a server created site pathdisplay.

asp .net note

Documents