DataGrid limitation

This week I hit a limitation in the Silverlight DataGrid control. I'm hoping it's just something I've not learned yet with bindings but it does appear that the simplest solution is to display the data in a different manner.

Problem: The data I'm trying to display is essentially a collection of collections of some object. So the rows can be any number, normal for a datagrid, and the columns are also any number. That's not so normal for a datagrid. Usually you have a set number of columns and your rows vary.

Solution: I tried adding columns to the datagrid dynamically, and while this worked just fine (adding them in codebehind) the real issue I hit was how to bind to the underlaying objects. The data is being built dynamically and I tried a couple of formats. I tried a collection of Arrays, and also an ObservableCollection of ObservableCollections. I could bind to the objects but as Bindings in Silverlight have to bind to properties I couldn't come up with a solution presenting the data this way.

My solution as a result has been to display the data in a more traditional manner, with a lists and a datagrid. When you select an item in the list it repopulates the data in the datagrid to show the objects.

If anyone comes across a way to bind a datagrid cell to a collection of collections please let me know.

Silverlight Xmas meetup

This month, I was toying with not actually having a meeting due to how close to Christmas the normal date falls.

My laptop has failed and I've been flat out with work. However, the room has been booked and I thought it would still be cool to meet up and chat about the newly launched Silverlight 4 beta, and have some Christmas drinks.

TOPIC: Christmas Drinks plus Silverlight 4 beta cheer
DATE: Wednesday, December 23rd, 6:00pm
VENUE: 43Below. 43 Barrack Street, Perth
COST: Free. All welcome

Be great to catch up.

Failed laptop

Ouch. My Dell m1730 which has served me fairly faithfully for the last 18+ months has died. The graphics card has always run really hot and it killed the battery some time ago. I replaced the battery (not knowing it was most likely the exessive heat) a few months ago.

My machine hung a few times and so I logged a call with Dell. they came and replaced the motherboard which is when the technician noticed the heat of the graphics card. 6 weeks later they replaced the graphics card. That was yesterday.. The technician left and one reboot later the machine would not boot. It would sit at 80% on the BIOS screen. I couldnt even get into the BIOS. So I called Dell and asked for my old graphics card back and the answer was no. ow!

The replacement graphics card is due in February which is probably another 6 week wait. I use this thing for work so that's not good for me. The option given to me by Dell was to replace the whole machine. I have a mate who had 7 faults in 9 months with this machine and they gave him an Alienware M17x of equal specs so that would be an excellent alternative for me.

Would be nice if I could add a few extras to it but I suspect they will choose the specs (equal or greater specs I was told). Thanks Dell!
My thought on Dell's is they are pretty good, but always get as much warranty as you can because faults can become very expensive. Lifetime of a laptop is 2 years for me so more than that is a bonus. I always get 3 years of cover.

Will let you know what I end up with.

EnqueueConditional never passing

I came across a unit test that seemed to hang. Problem was with the EnqueConditional() method which essentially never became true. A quick search turned up this blog post which has a solution.

Making sure asynchronous donesn't cause a deadlock

EnqueueConditional(() =>
{
// SP: Added timeout on checking the IsBusy
Assert.IsTrue((DateTime.Now - startTime) < TimeSpan.FromSeconds(30), "Timeout on condition 'StudImpVM.IsBusy == false;'");
return StudImpVM.IsBusy == false;
});

Adding this Assert into the conditional check causes it to fail the unit test rather than sit waiting for something that may never happen.

Perth SDDN Silverlight meeting for November

TOPIC: Ola Karlsson – Smooth Streaming
DATE: Wednesday, November 25th, 6:00pm
VENUE: 43Below. 43 Barrack Street, Perth
COST: Free. All welcome


This month Ola will be showing off how Silverlight handles Smooth Streaming.

Smooth Streaming is a feature of Internet Information Services (IIS) Media Services, an integrated HTTP-based media delivery platform.

Also there will be a license for Silverlight Spy to give away, as we forgot to give it away last month. oops!

Hope you can make it along.

Adobe PDF preview handler 64-bit fix

I came across this issue on my machine today and wasn’t sure if it was a first time thing or if it had always been there. I don’t normally preview PDF’s so much so possibly the later.

Anyway, the reg file did as advertised on this blog post. Thanks so much Adobe. 

Adobe PDF preview handler 64-bit fix

Basically:

Open RegEdit and go to:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes\CLSID\{DC6EFB56-9CFA-464D-8880-44885D7DC193}

There should be an existing AppID value, incorrectly set to {6d2b5079-2f0b-48dd-ab7f-97cec514d30b}

Change the AppID value to {534A1E02-D58F-44f0-B58B-36CBED287C7C}

SDDN Meeting October

TOPIC: Stephen Price – SketchFlow
DATE: Wednesday, October 28th, 6:00pm
VENUE: 43Below. 43 Barrack Street, Perth
COST: Free. All welcome

This month I’ll be doing a quick walkthrough of Sketchflow, a great tool for prototyping the flow of your Silverlight or WPF applications.

Look forward to seeing you there, and don't forget, bring a Designer with you!

I also have a license to Silverlight Spy to give away, it’s a great tool for finding out what’s going on in your Silverlight app.