View
215
Download
1
Category
Preview:
Citation preview
ASP.NET
Dr. Ralph WestfallMay, 2011
Web Development Problem
HTML designed to display static pages only interactive when user clicks links
can’t provide animation except How Do I Make An Animated GIF?
can’t create custom pages for specific types of customers
can’t use databases, spreadsheets, etc. no security capabilities in HTML itself
except hiding passwords <input type="password" etc.
using very long/random directory/file names works a bit, but it's not HTML
Solution 1: Client Side Scripts
JavaScript (dominant product) can do animation, rollovers, message boxes calculations, validation of user inputs incorporate customized content into pages
e.g. based on day/time, user inputs, etc. provide limited access to user’s system
system date, browser, plug-in informationset cookies (data for server for next visit)
Client Side Scripts (continued)
what (client side) JavaScript can’t do write meaningful data to files on the
server (other than cookies) provide adequate security for
access control (but JavaScript Source has some "hackish" scripts)
hiding proprietary code
Solution 2: Server Side Scripts
use common gateway interface (CGI)offer database & security capabilitieswritten in C, C++, Perl, Python, etc. relatively difficult to program & maintain
use server resources relatively inefficientlyseparate programs in addition to HTML but this is probably an advantage
Solution 3: "Classic" ASP
Microsoft's Active Server Pages released in 1996, works with Microsoft servers Windows Server 2008 free Visual Web Developer Express
2008 IDE includes a lightweight personal web server for developing ASP.NET applications
so does Visual Studio
Solution 3: ASP (continued)
simple languagecan go in same files as HTML codeprovides many of the capabilities of CGIuses server resources more efficiently than CGIusing ASP server extensions, can work with non-Microsoft servers, but …
ASP.NET
major revision of ASP can use different languages, not just
VB.NET VB.NET code looks more like Java
than the VBScript used previously .NET code is compiled into MSIL
(Microsoft Intermediate Language) MSIL is then interpreted into machine
language that runs on the server
ASP.NET: Many Languages
HTML (of course!)Visual Basic.NETcan also use C# and J# with VWDX.NET supports over 50 other languages C++ and JScript (Microsoft's version of
JavaScript) work with Visual Studio.NET other (non Microsoft) languages can
also work with Visual Studio.NET
Tools To Develop & Use ASP.NET
a tool to create code text editors: Notepad, TextPad, etc. HTML authoring tools: Dreamweaver,
FrontPage, etc. Visual Studio.NET, Visual Web
Developer Express 2008, Microsoft WebMatrix (2 free)
IIS or VWDX on your computer or free (for a while?) ASP.NET hosting
web browser
Simple ASP.NET
create ASP.NET projectProject>Add New Item>Web Formview Source window and add .NET code to file between <body> tags put:<% Response.Write("Hello, World!") %><p>The time is: <% = Now() %></p>
run code from that window
ASP.NET Coding within HTML
use <% at start, %> at endon same line (inline)
<% = Time %>or on multiple lines (block) <%
Response.Write("<P>Hello, World!")
Response.Write 'cf. Console.Write %>
ASP.NET Output in HTML
ASP inside a HTML tag <P>The time is: <% = Time %> use <% = followed by a variable or a
function that returns data, then %> variable can come from server itself, or
from client machine, or can be defined in code elsewhere in same or another ASP file
<% Dim strCar as String="Geo" %> <P>The car is: <% = strCar %>
Generating ASP Output - 2
ASP.NET code can write text and also data from ASP.NET variables <% Dim nAge as Integer = 22 nAge += 10 Response.Write("You will be" & nAge)
'text variable %>
Generating ASP Output - 3
can mix text, HTML, and ASP.NET variables in code this includes using ASP to write HTML
tags, in addition to writing variables and text
fontsize.aspx
<%
Dim intI as Integer
For intI = 1 to 7
%> <!-HTML inside ASP loop->
<font size = "<% = intI %>" >
Size is <% = intI %> </font><br/>
<% Next %> <!--what will you see from this? Notes about " "-->
Using ASP.NET with Forms
use HTML or ASP page to create a form be sure all form fields have id = "[ ]"
and also name = "[ ]" 'same as for id=
use an ASP.NET page to process inputs action attribute in form has name of an
ASP.NET file, and use Input (Submit) button
form field values accessible to ASP as Request.QueryString("[form field name]")
input.html
<form method="get"
action="output.aspx">
Last Name <input type="text"
name="custName" id="custName">
</form>
<!--need to refresh?-->
output.aspx
<!-- Visual Studio generated headers--> <html><body> Input from form: <% Dim strCustName as String
strCustName = _ Request.QueryString("custName")
Response.Write("last name is " & _ strCustName)%>
</body></html>
Using ASP.NET with Forms - 2
if have more than just one text field, must have a Submit button on form
<input type="submit" [etc.]> after development would use
<form method="post" [etc.]> when using post, also need to change
every Request.QueryString to Request.Form in the ASP page identified by the action
Another Demonstration
Create: Web Site… ASP.NET Web Siteadd a Label to Default.aspx designer and expand it vertically and horizontally to occupy 25% of the screen (could make Height="[]px" and Width="[]px"double click the screen (outside of the label) to start a Page_Load Subpaste code on following page into Sub
VB.NET Web Code
Dim i As IntegerDim colr() As String = {"000000", "333300",
_ "666600", "999900", "cccc00", "ffff00"}Dim output As String = ""For i = 0 To 5 output &= "<h1><font color=#" & colr(i)
_ & ">" & colr(i) & "</font></h1>"NextLabel1.Text = output
Run Code
click Start(first time) modify the web.config…>OKview code and then make changes as necessary
CIS 451 ASP.NET
ASP Code Samples
Recommended