Row not found or changed & LINQ

This is a particularly well-known error (see here, here, and here), but this is the second time that I’ve had to do a search on this error so I thought that I’d post it here so that I can find it more quickly. Anyway, when this error occurs, make sure that the NULL types in the LINQ dbml file match your SQL schema NULL types. Mismatches between the two seem to be a common cause of this error.


SaveFileDialog Error When Debugging Silverlight Applications

If you’re having difficulties debugging a section of code that uses the SafeFileDialog.ShowDialog() method, the reason is that Silverlight requires that the ShowDialog() method be called from a user-generated action. For whatever reason, entering into debug mode makes Silverlight think that you are not responding to a user-action, even when you are. To work around this, simply place the breakpoint after you call the ShowDialog() method.


Extending a UserControl in Silverlight

In a current project that I’m working on, I needed to extend a UserControl to add some additional specialized functionality. This is very easy to do if all you need is to extend code, but it becomes much more difficult if you want to extend it via a XAML/C# UserControl. After much web searching, I found a very simple and elegant solution, thanks to this site. Basically, all you have to do is modify the root element of your extended file as follows:


Where SomeBaseTypeYouWantToUse is the class that you’d like to extend. Simple!


Update (6/3/2010):I ran into some weird problems with this hack that I was unable to resolve. If anyone ends up reading this, please let me know if this worked correctly for your application.

Setting Document Root to Point to a Network Share With Windows/Apache

Quick tip: If you’re wanting to have your Apache document root point to a network share in Windows, here’s what you have to do:

  1. Change your DocumentRoot to the network share (drive remapping doesn’t seem to work).  Example: DocumentRoot “//path/to/share”
  2. Make sure to update the DocumentRoot path in your <Directory> config
  3. Edit the Apache service
    1. On the “Log On’” tab, click the “Browse” button next to the “This account” radio button.
    2. Type in an account name that has access privileges to the network share and click “OK”
    3. Enter the correct password for the user
  4. Restart Apache and LOL your way to the bank.