James Gregory

As part of my current quest to fully automate our build, I found my self needing the ability to copy a database backup from our remote server. The backup is in a folder along with several other backups, with a filename based on the date. I didn’t fancy trying to programmatically guess the filename, so I wrote an NAnt task to grab the newest file in a directory. Thanks to Richard Case for his overview of how to create a custom NAnt task.

The getfilename task simply gets the filename of a file in a directory, then pushes the name into the specified property. The filename to find can be based on the creation date, last modified date etc…

The DeleGrid is a paged GridView control that handles data-binding through the use of events and delegates rather than with a traditional collection.

What this means is that you have full control over the data that is shown in the currently displayed page. Traditionally you’d retrieve the whole recordset then page it locally, but with the DeleGrid you can utilise your database/ORMs paging features.

I’ve updated the ObjectField to be considerably simpler than it was before. While writing my Data-binding hierarchical objects post I wrote this about the BoundField implementation:

Using a TypeDescriptor to get the property… This strikes me as a bit odd to be honest, because the DataBinder has the ability to evaluate a hierarchical path.

Which is interesting, because I was using a TypeDescriptor in my ObjectField implementation!

After my post about my ObjectField column, I thought I’d elaborate a bit on why it’s necessary.

When you’re data binding against an object that isn’t flat (i.e. has properties that are more than simple types - namely classes), you are bound to encounter the following exception, which is caused by the BoundField incorrectly handling a hierarchical object path.

A field or property with the name MySubObject.PropertyName was not found on the selected data source.

The version of the ObjectField that this post refers to is now out of date. Please go to the ObjectField 1.1 post for the latest version.

I encountered a problem while binding a complex object to a GridView, in that the BoundField doesn’t support specifying a nested value in it’s DataField property. So if you have a list of Customer’s, and want to display the TelephoneNumber property from inside the customer’s ContactDetails property, you’re out of luck.

<asp:BoundField DataField="ContactDetails.TelephoneNumber" />

The above would fall over with an exception along the lines of: A field or property with the name 'ContactDetails.TelephoneNumber' was not found on the selected data source.