Archive For August 2007

Referencing CheckBoxes in GridView, Repeater and DataList controls

calendar_today 30 August 2007 10:29

ASP.NET 2.0 ASP.NET Web Forms

If you want to find which CheckBoxes were selected in a multiple record DataBound control, the way that you you do it depends on the type of control you use. These examples demonstrate a CheckBox control being added to a GridView, Repeater and a DataList. For simplicity, I have placed all three controls on the same page, and used the Access version of theNorthwind database. One AccessDataSource control is used to bind the results of "SELECT [CategoryID], [Description], [CategoryName] FROM [Categories]" to all three controls.

ViewState, form fields, labels and Javascript

calendar_today 25 August 2007 12:34

ASP.NET 2.0 Javascript ASP.NET Web Forms

An interesting question came up on the ASP.NET forums asking why a TextBox which has its value changed by client-side Javascript persists those changes across postbacks, while a Label does not. And in a nut shell, this question covered two of the biggest causes of confusion among newcomers to ASP.NET: the difference between ViewState and IPostBackDataHandler; and the difference between client-side operations and server-side operations.

Bind Data From a SqlDataSource to a Label

calendar_today 25 August 2007 10:32

ASP.NET 2.0 ADO.NET ASP.NET Web Forms

Label controls in ASP.NET don't have a smart tag that allows you to select a data source, so at first glance, it is not easy to see how to bind a value returned from a SqlDataSource or AccessDataSource control to the label. Here's how to programmatically access the data returned by such a DataSource and apply it to a non-databound control.

Object reference not set to an instance of an object and INamingContainer

calendar_today 21 August 2007 11:36

ASP.NET 2.0 ASP.NET Web Forms

A list of standard ASP.NET web controls that implement INamingContainer

Consuming RSS feeds in an ASP.NET page

calendar_today 18 August 2007 23:12

ASP.NET 2.0 ASP.NET Web Forms

I like reading Scott Guthrie's blog. Trouble is, I get so busy, I forget to go over there and have a look to see what's new. I was searching for something the other day, and stumbled across someone else's blog (I forget whose), but I noticed that they had the 5 most recent items in Scott's blog embedded in their home page. It was only then that I discovered that Scott Mitchell has written a whole load more tutorials on Data Access, and that these have been available for a while. So I got to thinking that I should add a feed from Scott G's site onto the home page here, so I can be updated more quickly. Here's the bare bones of how I did it.

Debugging Classic ASP pages in Visual Studio 2005 on Windows XP Pro

calendar_today 17 August 2007 10:28

Classic ASP Visual Studio

As an ardent Dreamweaver user for classic ASP, I used to debug my scripts with a plethora of Response.Write and Response.End statements, outputting the values of various values to the browser to check that logic was working as intended. However, I recently discovered how to use the VS 2005 debugger to make debugging classic ASP (almost) a joy.

List the contents of a folder and link to each file

calendar_today 10 August 2007 21:33

ASP.NET 2.0

Iterating the contents of a folder is straightforward using classes from System.IO, and listing them as links to the actual file just requires a bit of html added to each file name.

Exporting data to a CSV, tab delimited or other text format

calendar_today 02 August 2007 23:41

ASP.NET 2.0 ADO.NET

A question that often comes up in forums is how to export data to a CSV file, or other text format. Here's a method that takes data from a DataReader and writes it to a file.