Sunday, February 22, 2009

Binding to SelectedItems in WPF ListBox.

Here's a very interesting approach to solving the "can't bind to selected items" issue with the WPF ListBox control.  I'll definitely want to look into this more later, as I haven't had a chance to yet.  I'm still fighting issues getting CheckedItems initialized on my CheckListBox control that I've written and it suffers from the same issue as SelectedItems in ListBox.

Alex's blog has the approach I'm referring to.  Check it out.

Saturday, February 21, 2009

Holy Crap! HyperV versus nVidia drivers - everyone loses!

Wow, I've been trying to figure out why WPF apps are soooo slow on my machine for months now. I just chalked it up to Server 2008 being a server OS and having all the goodies for fast rendering turned off, or something like that.

Today, I stumbled across a post on a forum about problems with HyperV causing video and other apps that "use" video to be really slow on startup and run very sluggish, causing problems with audio and other side effects. It turns out that many (most) video drivers do not play well with HyperV (or HyperV doesn't play well with most video drivers - I'll let MS & the vendors argue over which is the correct statement, I'm staying out of the middle). As such, when running HyperV, the machine can be very sluggish when apps do anything that accesses the video hardware (obviously something that VS2008, VLC media player, and WPF applications do a lot of).

Finally, I bit the bullet and decided to uninstall HyperV and after doing so, my apps immediately run way faster. I'm not sure exactly how much faster, but I know that when running my UITestHarness app (part of the project I work on), the app would start up rather quickly, but when clicking on a button that shows a WPF window (the app is WinForms mainly), it would take a good 15 seconds to show the window. Now, those windows show immediately (less than 1 second). I find this rather amazing that there are such perf differences between HyperV and non HyperV configs. Oh well, hopefully they'll fix them soon, or I'll find a video card that doesn't have problems (reportedly ATI cards are often in better shape), 'cause I really like HyperV!