asp by okyestao

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									CIS 451:
Introduction to ASP.NET

    Dr. Ralph D. Westfall
    January, 2009
    Web Development Problem
   HTML designed to display static pages
       only interactive when user clicks links
            can’t provide animation
                 except animated GIFs
            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 long directory/file names works
             somewhat, 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
             information
            set cookies (data for server for next visit)
    Client Side Scripts (continued)
   what (client side) JavaScript can’t do
       connect with databases, and possibly other
        applications on the server
       provide meaningful security for
            access control (but JavaScript Source has
             some "hackish" scripts)
            hiding proprietary code if it's in the HTML
             file or user has a tool to find it (e.g., Web
             Developer add-on for Firefox)
Solution 2: Server Side Scripts
   use common gateway interface (CGI)
   offer database & security capabilities
   written in C, C++, Perl, etc.
       relatively difficult to program & maintain
   use server resources relatively
    inefficiently
   separate programs in addition to HTML
       but this is probably an advantage
Solution 3: ASP
   Active Server Pages
   released by Microsoft 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 language
   can go in same files as HTML code
   provides many of the capabilities of CGI
   uses server resources more efficiently
    than CGI
   using 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.NET
   can also use C# and J# with VWDX
   .NET supports over 30 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, Web Matrix or Visual
        Web Developer Express 2008 (free!)
   IIS or VWDX on your computer
       or free 14-day ASP.NET hosting
   web browser
Creating an ASP.NET Page
   create an HTML document
   add ASP code in appropriate places
   save with extension of .aspx
   if don't have local server on computer,
    upload to a remote ASP.NET server
       Cal Poly Intranet server won't run ASP
   view in browser (file can be on local
    machine with server or remote server)
Simple ASP.NET Page
(not Visual Studio)
   create a document with HTML code
   add .NET code within HTML (inline)
       at top, need
        <%@ Page Language="VB" %>
   save with extension of .aspx
   upload to remote server (if don't have
    Web Matrix or IIS) or paste into VS
   view in browser
hello.aspx
 <%@ Page Language="VB" %>
 <html>
  <body> <!-- paste below </form> tag-->
   <%
     Response.Write("<P>Hello, world!")
   %>
     <P>The time is: <% = Now() %>
   </body>
 </html> <!-- View Source in browser -->
ASP.NET Coding within HTML
   use <% at start, %> at end
   on same line (inline)
      <% = Time %>
   or on multiple lines (block)
      <%
    Response.Write "<P>Hello, world!"
    Response.Write 'like VB.NET Debug.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
       hit counter example
        <%
        nHits = nHits + 1
        Response.Write "Hits = " & nHits
                       '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 %>               <!-note->
 <!-what will you see from this?->
 <!-fontcolor.aspx 'notes->
    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]")
form2.html
<html><body>
 <form method="get"
 action="resp2.aspx">
 Last Name <input type="text"
 name="custName" id="custName">
</body></html>
<!--need to refresh?-->
Default.aspx
 <%@ Page Language="VB" %>
 <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
Using Visual Studio.NET for ASP
   using Visual Studio.NET or Visual Web
    Developer Express 2008
       Create: Web Site… ASP.NET Web Site
       add a Label to Default.aspx designer and
        expand it vertically and horizontally to
        occupy 25% of the screen
       double click the screen (outside of the
        label) to start a Page_Load Sub
       paste code on following page into Sub
VB.NET Web Code
Dim i As Integer
Dim 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>"
Next
Label1.Text = output
Run Code
   click Start
   (first time) modify the web.config…>OK
   view code and then make changes as
    necessary
ASP.NET Code Samples
   CIS 451 ASP Code Samples
   W3 Schools online tutorials and
    demonstration code

								
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