Automatically adding ValidatorCalloutExtenders to your validators
I recently had to work on a pretty big ASP.NET page with lots of fields that needed to be validated.
We thought it would be cool if we used the AJAX Toolkit ValidatorCalloutExtender control on the validators to keep the validation inline and concise.
To quote from the AJAX Toolkit page:
ValidatorCallout is an ASP.NET AJAX extender that enhances the functionality of existing ASP.NET validators. To use this control, add an input field and a validator control as you normally would. Then add the ValidatorCallout and set its TargetControlID property to reference the validator control.
Because we had over 30 text fields, it would have been really tiresome to add extenders manually to each of the validators. So a way to attach them dynamically was needed.
Fortunately, this is pretty easy to do by iterating through the Page.Validators collection, dynamically creating ValidatorCalloutExtender controls and adding them to the Page.
Challenges
- The first problem I had was an error that occured when trying to dynamically add controls to the Page.Controls collection:
Owner-drawing a Windows.Forms TextBox
This article describes how SharpSpell is able to modify existing TextBox controls to display wavy red underlines below misspelled words.
Here’s an image to demonstrate what I mean:

(This image is borrowed from SharpSpell, but you get the point) (more…)
Calling a Windows Service from ASP.NET via Remoting & IpcChannel
I recently had to design a Windows Service that connects to several game servers via UDP, gathers stats, and then updates a MSSQL database.
These stats were then made available in real-time on a web-site written in C# and ASP.NET.
Before Remoting
For the first version of the application, the web-site and Windows Service were completely independent. The web-site would just query the database and determine, or make a best guess about what was going on inside the Windows Service at that exact time. This worked pretty good, and although the database is now about 1GB in size and growing fast, I optimized it good enough for this to work in real-time without a hitch.
There was some caching going on, thanks to the OutputCache directive in ASP.NET, but surprisingly enough there were no performance issues.
After Remoting
All right, so because I needed to display some extra information about ‘online’ users, that the Windows Service knew about, but the database didn’t, I decided to have a look at .NET Remoting. This was my first time working with it.
These were the issues I experienced (as a Remoting newbie) when rewriting the Windows Service to be accessible via .NET Remoting: (more…)
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