I've just fixed a strange bug I was having when comparing a web page in IE and Firefox. The page simply had a single textbox, and a button. By default, in accordance with W3C standards, both browsers will post-back to the server when the user hits <Enter> from within the textbox.

Just the behaviour I wanted, except that when the post-back occurs from IE, the button's event handler does not get triggered on the server!! Very strange ... but this article on 4guysfromrolla.com gives a great explanation.

Basically, IE does not post-back a fully serialised form if there is only one textbox on the page! The server does not know what triggered the post-back and so cannot call the correct server-side event handler. The workaround? ... add another textbox to the form (but just make it hidden!).

This is true for IE6 and IE7 ...

It's not an error message that you see often when working with ASP.NET, but if you’re deploying to a new, clean machine, it can happen quite easily.

The problem comes around due to the order that components were installed on the machine, namely that The .NET Framework was installed before IIS. As a result, ASP.NET is not correctly configured to run. The easiest way to rectify this is to re-install ASP.NET with IIS.

aspnet_regiis –i

If you only require default settings then this is the easiest option. The Microsoft KB specified in the error message suggests the –ga switch, but that requires a little more knowledge of the Windows system as it requires you to specify the Windows User Account to run under (which is different between Windows 2000, XP, 2003, etc). Easier to simply use the –i switch!

A problem I had recently was that a GridView bound to a SqlDataSource was not deleting the records when the Delete command was executed. I've tagged this entry as a "gotcha" as it isn't completely obvious where the problem might be to the uninitiated.

The Delete Sql command was executing fine, but after using SqlProfiler I noticed that the “ID” parameter was set to “Null”, hence the fact that no record was deleted. This was not what I expected as I had used the normal SqlDataSource and DataGrid wizard to set up the controls. What I was missing was setting the “DataKeyNames” property on the GridView to the name of the primary key of my data … “ID”. Now, the SqlDataSource passed through the correct Sql statement and all was good!

I’ve avoided the SqlDataSource/Designer approach whenever possible for the very reason that it’s difficult to see what’s going on when something doesn’t work. I was creating a prototype so time pressures won out and I used it!