Useful ASP.NET Hints and Tips

Slow web pages - updating some bits after the page has loaded

2008-09-11T17:59:00.003Z

On one of my websites, I was finding that a particular database operation was taking a long time to execute. This in turn meant that the web pages were loading slowly as the user's browser was waiting for my server to return all of the data to display.Some of this data was not needed to be on the page straightaway, so I needed to investigate if I could make a JavaScript update to the page after

An AJAX control to see search results as you type

2008-03-14T12:05:00.002Z

I have a web form which displays search results. When I type in a new search string, press a button, it then updates the results.I needed to change this so that, as I type, the keystrokes cause the search to be run immediately and so the more I type, the results are filtered more and more. This required use of the AutoPostBack method and a check for the keyup() event of text input.Example:Type 1

Authenticating against Active Directory for Forms Authentication

2007-09-05T08:09:00.000Z

The code snippet below is used on some private sites (not exposed to the internet) which enables a windows forms web page to allow input of an active directory username and password and authenticate. The machine hosting the web page is a member of the domain (or trusts the domain).It's probably not ultra secure, but fulfills a purpose. Beware of some word wrap below.Imports

Multi threaded code

2007-08-30T12:44:00.000Z

Very occasionally, I need to fire off two worker processes in ASP.NET to handle a couple of tasks, and then when done, continue with the rest of the code in a web page.It has taken me ages to actually get around to doing this, until a multiple threaded application was required which may spawn 10 or more threads. So, I trawled around the 'net and got a solution together.This solution is in VB and

Asynchronous logging routine - VB.NET

2007-07-09T13:04:00.000Z

I have a number of applications in which there is a need to write out information to a database, be it due to a fault, or some condition that I want to trap.One thing I don't want to do when doing this, is to hang up the user experience whilst my logging is taking place, so I use a Delegate in ASP.NET to handle it for me. I send a request and then forget about the command.Below is some code I

Looping through role based security

2007-05-25T09:52:00.001Z

I came across a problem today in that I wanted to check whether a particular user had any permission to access a website, but needed to do this from another account, so using theUser.IsInRole() couldn't be done.This was relatively trivial - I needed to return all the roles, and then check each one to see if the user was contained within. It may be useful for someone else out therebool permission

CSS Friendly Control Adapters

2007-05-22T07:02:00.000Z

The CSS Friendly Control Adapters were created to avoid the rendering of certain ASP.NET controls being done with tables, and instead to use CSS. They are good in doing this, and I use them in a number of places.The adapters can change the rendering of the TreeView, Menu, DetailsView, FormView, GridView and DataList controls, as well as some of the Login controls.You don't have to use them for

Capturing Asynchronous Ajax errors

2007-05-04T13:09:00.000Z

I had a problem with some random asynchronous errors that an Ajax application was happening. Because they caused an error to be displayed on the client, I needed to be able to see them myself.When investigating the problem, I came across this post on forums.asp.net, which prompted me to write a piece of code to email me when errors happen.I use master pages, so this was a simple matter of just

Generating a shadowed page title in an HttpHandler

2007-04-14T10:22:00.000Z

Here is some code I recently wrote to handle a dynamic image of some text with a shadow on it. I use a slightly more customized version, but this may help if you need to so something similar.It uses an Http Handler (.ashx file), and the image output can be referenced just by using an IMG tag, with the SRC pointing to the handler.<%@ WebHandler Language="C#" Class="pagetitle" %>using System;using

Last day of the month

2007-03-30T09:06:00.000Z

I needed to generate the last day of the month for some code I was writing. It actually took me a little while to search for information on the internet, so in the end, I coded it myself.Here's the code I used, based on the date being today:Public Function GetLastDate() As DateDim thedate As Date = Now()Return DateSerial(Year(thedate), Month(thedate), 1).AddMonths(1).AddDays(-1)End Function

Simple mail subroutine for asp.net 2.0

2007-03-29T08:53:00.000Z

Below is the common mail handling routine I use for sending mail in all projects.Imports System.Net.MailPublic Class MailPublic Shared Sub sendEmail(ByVal sender as String, _ByVal sendername as String, ByVal recipient As String, _ByVal subject As String, ByVal message As String)' Sends a mail message using the specified detailsDim myMessage As New MailMessagemyMessage.From = New MailAddress(

Modal Popup with Textbox and Validator

2007-03-19T14:03:00.000Z

I ran into an issue today where I wanted to create a modal popup in ASP.NET 2.0 using Ajax, but also use a validator on a textbox which was part of that popup. This proved to be more complex than I hoped, but I just about got it working:The code I used was as follows:In the ASP.NET form, the following code is at the top of the page<

IP Address filtering with an XML Data Source

2007-03-19T11:32:00.000Z

IP Address filtering in ASP.NET 2.0 using an XML data source for the blocked IP addresses.This was an article wrote in 2006 to allow certain URLs to be denied access to the website, and returns a boolean value to say whether the site should be blocked or not.

Tip/Trick: Url Rewriting with ASP.NET

2007-03-12T22:14:00.000Z

ScottGu's Blog : Tip/Trick: Url Rewriting with ASP.NETLots of different ways of using URL rewriting. Useful to avoid scenarios where web pages are extracted from a database and allows friendly URLs, rather than ones which use querystring parameters.This post is from my favorite asp.net source, which is Scott Guthrie - the person who runs the group which designs asp.net products.