An Introduction to ASP+ in .Net

An Introduction To ASP.NET
K. Yue, copyright 2001
Created April 3, 2001

Introduction

ASP.NET is used to be called ASP+.
ASP.NET is the 'glue' technology of the Microsoft's .NET framework.
The .NET Framework is an environment for building, deploying, and running Web Services and other applications.
The .NET consists of three main parts:
- the Common Language Runtime,
- the Framework classes
- ASP.NET.
The .NET framework is Included in the .NET SDK beta.
Getting started by downloading and installing the .NET SDK: MSDN's article on getting started.
ASP.NET is backwards-compatible with earlier versions of ASP.
Can co-exist with ASP 3.0.

Advantages of ASP.NET

Improved Performance
- Compiled to CLR (Common Language Runtime) code.
- Built-in Cache: output caching and data caching.
Improved Scalarability
- Distributed session: sessions may be maintained as a separate process, in a separate machine or in a database.
- Processes are closely monitored by ASP.NET runtime for deadlocks, etc.
Better development
- More object-oriented approach.
- Server controls with namespaces.
- Tight XML support.
- Caching
- ADO+ for better database access.
- New classes such as Trace for debugging and development.
- Better separation of logic and presentation.
- Better component model based on COM+.

Simple Examples

Example: datagrid

<%@ language="vb" %>
<%@ import namespace="system.data" %>
<%@ import namespace="system.data.ado" %>

<script language="vb" runat="server">
dim cnn as adoconnection
dim cmd as adodatasetcommand
dim ds as new dataset

public sub page_load(sender as object,e as eventargs)
    if page.ispostback=false then
        cnn=new adoconnection("dsn=mydsn")
        cmd=new adodatasetcommand("select * from sometable",cnn)
        cmd.filldataset(ds,"result")
        resultgrid.datasource=ds.tables("result").defaultview
        resultgrid.databind()
    end if
end sub
</script>

<form id=form1 runat="server">
<asp:datagrid id="resultgrid" runat="server"
    font-name="Verdana"
    font-size="10pt"
    BorderColor="black"
    CellPadding="3"
    headerstyle-backcolor="gray"
    headerstyle-forecolor="black"
    alternatingitemstyle-backcolor="silver"
    itemstyle-backcolor="#ccccff"/>
</form>

Notes:

Importing namespaces are similar to using packages in Java.
Visual Basic is used, not VBScript.
Visual Basic is more object oriented. For example, note the use of the new constructor.
Dataset is used in ADO.NET instead of RecordSet in ADO.
asp:datagrid is one of the built-in ASP.NET server controls.

Example:

drawing.asp

<%@ Page Language="C#" Debug="true" %>

<html>
<script language="C#" runat=server>
private void btnclick_click(object sender, EventArgs e) {
   int i = 0;
   i = int.Parse(txtRed.Text);
   i = i * 256 + int.Parse(txtGreen.Text);
   i = i * 256 + int.Parse(txtBlue.Text);
   lblcolor.BackColor = System.Drawing.Color.FromARGB(i);
}
</script>
<body>
<form action="drawing.aspx" method="post"
      runat="server">
<asp:Label runat="server" id="lblcolor"
    Text="CSCI 4230 Internet Application Development"/>
<br><br>
Red (0 to 255):
<asp:TextBox id="txtRed" Text="0" Width="3em"
             runat="server"/>
<asp:RangeValidator id="redVal" Type="Integer"
    ControlToValidate="txtRed"
    MaximumValue="255" MinimumValue="0" runat="server"
    ErrorMessage="Number must be 0 to 255!" runat="server"/>
<br>
Green (0 to 255):
<asp:TextBox id="txtGreen" Text="0" Width="3em"
    runat="server"/>
<asp:RangeValidator id="greemVal" Type="Integer"
    ControlToValidate="txtGreen"
    MaximumValue="255" MinimumValue="0" runat="server"
    ErrorMessage="Number must be 0 to 255!" runat="server"/><br>
Blue (0 to 255):
<asp:TextBox id="txtBlue" Text="0" Width="3em"
    runat="server"/>
<asp:RangeValidator id="blueVal" Type="Integer"
    ControlToValidate="txtBlue"
    MaximumValue="255" MinimumValue="0" runat="server"
    ErrorMessage="Number must be 0 to 255!" runat="server"/>
<br><br>
<asp:Button Text="Click Here" id="btnClick"
    onClick="btnclick_click" Runat=server />
<br>
</form>
</body>
</html>