COS 381

Day 26

Agenda

Capstone projects are DUE May 10 at 1PM I will be covering ASP.NET from the handouts There will be one lecture on Database access Quiz 4 on May 4

ASP.NET and Database Access Assignment 7 (final one) is posted and is Due on

May 3 at Midnight Create a complex ASP.NET page http://perleybrook.umfk.maine.edu/samples/

assign7/UMFKorder.aspx

ASP.NET

Where ASP used interpreted languages ASP.NET uses complied languages ASP example (code) Same in ASP.NET (code)

ASP.NET uses many languages We will use C# Another example (code)

NEW Features of ASP.NET

The following are not part of ASP or any other traditional Web programming languages Server Controls Validation Controls List Controls and Rich Controls HTML Server Controls User and Custom Controls Web Services Integration

Server Controls

Programmable; prepackaged server code program code written to perform dynamic functions <asp:tagname …> Converted to HTML by server Look the same as standard from

elements but can be dynamically control by server side code at run-time

Example server controls (code)

Validation Controls

Used to validate data users enter into from elements Make a field required Compare against range of inputs Compare two values

Validation controls process data BEFORE a form is submitted

List Controls and Rich Controls

List controls are used to iterate, process and display dynamic data Database query Program array

Rich controls are complex components Calendar Ad Rotator

HTML Server Controls

Same as HTML elements except runat=“server”

Example (code)

User and Custom Controls

User Controls Mini-ASP.NET pages Included in other ASP.NET pages

Custom Controls Written entirely in another language

like C++, C# VB

Precompiled and added to ASP.NET

Web Service Integration

Small Programs to which you can call functions and get results

Transfer data using XML over HTTP AN Example

US Postal Service has web service to output all ZIP Codes

In order to include ZIP Codes in your ASP.NET application you simply poll the USPS Web Service

Web Service

HTTP Response

HTTP Request

Client PCWebserver

SOAP-CapableBrowser

WebService

--Interface

PropertiesMethodsSOAP Message

Using XML Syntax

Web Service

Similarities to ASP

ASP pages coexist with ASP.NET Cannot share session information

Still have Response and Request objects All info requested with a web page

Form data Query Strings

All info returned with a webpage

Components of .NET

3 major parts Common language runtime (CLR)

A virtual machine that runs all .NET programs Run-time language is Microsoft Intermediate

language (MSIL) Uses JIT Compilation

Common type system (CTS) Standard set of types

Value types (int, char…) Reference types for objects

Common naming convention (CLS) Class Library

Predefined code packaged as classes All .NET classes or part of System namespace

Class Libraries

Namespaces Hierarchical naming convention Matches class inheritance tree

Common Namespaces in .NET System root namspace System.data System.xml System.net System.security System.web

Writing C# code in .NET

Object oriented Class

public class Car { } Object

Car c = new Car(): Member variable

private int Gas; Method

private void Drive() {} Property

Public int Gasoline { get {return Gas; } set {Gas=value;}} Overloading

Method with different parameter list Inheritance

The power of OOP

Getting Started with .NET

Installing .NET Need .NET SDK

Loaded with Visual Studio .NET Available under MSDNAA

Need IIS Personal edition or Server

Microsoft Data Access Components (MDAC)

For data base access Service packs and updates

.NET Framework SDK

Assemblies ASP.NET pages Executed in CLR

Metadata Data about data Provides location of class definitions. How to

load classes and any defines attributes Global Assembly Cache

Centralized locations for assemblies

Working with Dreamweaver

Chapter 3 of text provides a good overview Only issue is that it assumes that you

have a web server available on your Desktop..we do in N-105. You may not have on your home computer

Setting up Dreamweaver MX to Create ASP.NET Applications

Open Dreamweaver MX. Select Site > New Site… from the Menu bar to create a

new site. On the Basic tab, enter the following information,

clicking Next at the bottom of each screen:   Name: MyASPNET Yes, I want to use a server technology.

Select ASP.NET C# as the server technology. Edit and then upload to remote testing server, storing

your files at H:\asp. URL to browse to the root of your site

http://perleybrook.umfk.maine.edu/classes/cos381/”last name”.

No, do not copy files when I am done editing. Click Done to create an initial cache of your site. Lets do this “Step by Step”

Web Form Controls

Learn by doing Create new ASP.NET C# page

Insert new Form Element

Set to Run at Server

Add Label Control

Web Form

Save and test previous example Go to “View Source”

Building Dynamic Pages

Update page based on external conditions

runat=“server” means that a control can be manipulated

Let’s modify our page to display an user input ADD asp:textbox ADD asp:button

Then we add a Page Load Function

Change Function text

About Post Back

Form “post’ back to themselves No need to reload form Makes the form interactive

isPostBack is true when Something control has caused the form

to be to be sent to the server and the form is “reloaded”

Problem is that you allways return to the same form page

Form vs Query Srting

In CGI programming we used the Query String to collect data from a form and pass it to our script Uses method=“get” Security/performance issue

In ASP.Net We use the action=“post” and read our values

from the response object Response.Form[“txtFirstName”]

We use get when we want to load a different page and pass data to the page

<a ref=“http://url/webform.aspx?data=stuff” >stuff</a>

Using Request.Form

Add Text

Examples ASP.NET

All examples from class are at http://perleybrook.umfk.maine.edu/samples/AS

PdotNet/script.htm Today’s Example (so far)

WebForm1 (code)

Moving between pages

Since Web Form Post Back ….how do you go to another web Page? Response.Redirect(“Url”);

If you don’t want to finish processing the page you are on Response.Redirect(“Url”, true);

The hidden form element __VIEWSTATE gets lost

Session Variables

To move data between different Web forms you can use Session Variables To Set a Session Variable (original Web Form

Session[“aVariable”] = “some data”; To get a Session Variable (second Web Form)

lblSomeLable.Text = Session[“aVariable”].ToString();

String str = Session[“aVariable”].ToString(); Example (code1) (Code2)

Working With Drop-Down Lists

To add a Drop Down use Dreamweaver’s wizard

Drop Down List

Coding Drop Downs In Body section

<asp:dropdownlist ID="dblSampleList" runat="server">

<asp:listitem>List Item 1</asp:listitem></asp:dropdownlist>

To add a item dynamicallydblSampleList.Items.Add("List Item 2");dblSampleList.Items.Add("List Item 3");

Example (code)

Binding Data

Used for binding data from a Database or an array to a controls at run time Another way to add list items Bind values to variables

Two Styles for Binding Data exist Textbook Error

References to BindData() should be change to DataBind()

Binding Data

First Style <%# variable %>

In body of HTML Type in or use ASP.NET Bound Data Icon

in Dreamweaver Must call Page.DataBind(); in Page_load

function (note error in text book!) Will be replaced by value of variable

Second Style

Binding Data

Second Style In Page_Load Function

someList.DataSource = someList; Page.DataBind();

Example (code)

Event Handling in ASP.NET

Events are messages sent out by objects Different objects – Different messages

In ASP.NET events occur when the server detects an event page-Level events

Occur when users visits a web page Control events

Occur when a user manipulates an ASP.NET control

Page Events

Web Form trigger 11 events when loaded (in order)1. Initialization (Page_Init)2. Load View State3. Post Back Data Processing4. Page Load (Page_Load)5. Post Back Change Notification6. Post Back Event Processing7. Pre-rendering (Page_PreRender)8. Same view State9. Rendering10. Disposing11. Unload

Page Level Events

These events do not need to be registered Most common Used Page Event is

Page_Load<script runat="server">protected void Page_Load(Object Src, EventArgs E){ if (!PostBack) DataBind();} </script>

Example (code)

Control Events

Must have registered Handlers Use Delegates which listen for events

and then delegating responsibility for the event to the assigned handler

Generally event handlers (like Page_Load) have two parameters

Object src The object which created the event

EventArgs E Specific information about the event

Creating a handler for a ASP.NET Control

ASP.NET Control must be in a Web Form that is set to runat=‘server”

Use Dreamweaver Wizard

Control Events

The Dreamweaver wizard will register the event but you still need to write the handler code Between <script> tags in Head

void btnTest_OnClick( Object Src, EventsArgs E){

Some C# code }

Example (Code)

Adding Controls and Events Programmatically

Between <script> tags in head Button btnTest = new Button(); btnTest.Text = “daButton”; btnTest.Click += new

EventHandler(this.btnTest_OnClick); samePanel.Controls.Add(“btnTest”); Make sure you write the

btnTest_Onclick functions Example (code)

Complex Controls

Have lots of functionality; sometimes called rich controls

We will look at two complex controls Ad Rotator File upload

You can create your own Complex Controls (chap 10 & 11 in text)

AD Rotator

Places Different images in your Web Form every time someone loads the page. Images are licked to a web site 3 Parts

Images The ASP.NET Ad Rotator Control A XML configuration file

Example (Code)

XML config File

<?xml version="1.0" encoding="iso-8859-1" ?> <Advertisements>

<Ad><ImageUrl>*.jpg</ImageUrl> <NavigateUrl>URL</NavigateUrl> <AlternateText>text</AlternateText> <Impressions>50</Impressions><Keyword>Macromedia</Keyword>

</Ad><Ad>

<ImageUrl>*.jpg</ImageUrl> <NavigateUrl>UrL</NavigateUrl><AlternateText>Text</AlternateText><Impressions>30</Impressions> <Keyword>Microsoft</Keyword>

</Ad></Advertisements>

example

Adding The Ad Rotator Control

Use Dreamweaver wizard More tags icon Under ASP.NET tags use asp:adrotatoor

Web Form Validation

Input fields need to be checked Check for errors before using the data in a

program or putting into a database We can check for

Existence Format Range of vales Data type

ASP.NET includes validation controls that automatically provide form field validation with little or no extra coding

Preprogrammed Validators

Does both client side and server side validation of data DHTML

CSS JavaScript

ASP.NET includes 5 preprogrammed Validators Required field Range Compare Regular expression Custom

Adding a Required field validator

Must use a Web Form that runat=‘server”

Adding a Validation summary

This is a place for all the validation errors to appear

Example (code)

Value Based Validators

Required Text Validators only require that some text is entered but you may want to check to actual text entered Compare against

Value (compare validator) Type (compare validator) Another control (compare validator) A regular expression (regular expression

validator) A range of values (range validator) Other conditions (custom validator)

Adding value Validators

Regular Expression

Same as JavaScript and Perl \w is alpha char \d is decimal char * zero or more + one or more ? Zero or one . Matches any character except newline [] range of characters [A-Z] upper case \* matches * \w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)

Matches e-mails

Validations examples

Compare, Range & Regular expression Example (code)

Custom validator Example (code)

Assignment #7 http://perleybrook.umfk.maine.edu/samples/assign7/UMFKorder.aspx