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Crashing WPF app with Regional settings

2010-02-19T21:56:00.008+02:00

Recently a buddy from the Support team came over and complained that Quorum stopped working on his (Vista, .NET 3.5SP1) machine suddenly. Funny part is that the app kept crashing at the point of displaying the WPF window (splash screen) and we all assumed (burned by the previous experience) that it's the graphics driver issue.

Updating the drivers did not solve the problem and we were back to the machine Event log, where we noticed the following entry (Event 1001, name CLR20r3):

The machine did not have VS installed so we tried hooking-up the command line debugger (MDbg.exe) from the .NET SDK and the following exception was thrown:

Cannot convert string in attribute 'EndPoint' to object of type 'System.Windows.Point'. Premature string termination encountered.  Error at object 'System.Windows.Media.LinearGradientBrush' in markup file '...;component/wpfwindow.xaml' Line 20 Position 34."

Puzzled. The same code worked as a breeze on another machine with the same hardware (at least the graphics subsystem) and we started comparing the settings, installed apps, updates, etc. The part of the message saying "Premature string termination encountered" indicated that something is wrong with the way the XAML is parsed and probably the delimiter cases were wrong. But the regional settings were set to US English and there was nothing unusual. Trying to change the list separator made no difference. Then, the guy remembered that he wanted to test certain functionality on his machine as reported by the customer, so he played with regional settings trying to reproduce the bug. Result was devastating: not just that he almost got the machine cleaned and paved with the fresh Vista installation, but he was also not able to help the customer asking for a totally different thing.

Googling the problem revealed the following MS KB entry:

FIX: An exception in the XAML parser is thrown when you run a WPF application on a computer that has customized English (United States) regional settings

Obviously, resetting the settings (changing to 'UK English' and then back to 'US English') did solve the problem, and luckily, we did not yet have reports from customers about similar situations. The link above states that the fix can be obtained if the "MS Customer Support Center is contacted". I still wonder why the update has not been released as hot-fix download or maybe even part of the Windows Update?? It remains to test the same behavior on .NET 4 and see.

Microsoft Momentum 2009

2009-12-10T18:17:00.033+02:00

Last month there was an MS event going on in Cyprus, Momentum 2009. Being different from previous events, this one seemed to me as the best until now. If nothing else but because of the venue where the event took place.

Usual MS events in Cyprus are 'played' at the hotel conference rooms while this year's Momentum had a full-size Hall within the Cyprus State Fair exhibition area. Professionalism was on their side this time.

From the side of the CDNUG, we kept the Developers track (there was IT track going on in parallel) together with Karl.

I talked about Windows API CodePack and all nice UI goodies in Windows7.

Artemis has more details about the event and his session here.

General Dev. track review can be found on the CDNUG website here.

Desktop app and Paging the results list

2009-10-11T20:55:00.010+03:00

Probably something you have been burned with in the past, while working with the potentially large sets of data, was the efficient display methods. Ever since I started playing with the WPF and the powerful binding it brings, I have faced poor performance when binding substantial result sets to a ListBox for example.

Then, the virtualization comes along: being able to allow platform to render just the required number of results that are visible at the specific point of time provides much better results. I must admit that it was a cumbersome process at first, but the results were impressive and that made me understand the virtualization sooner than expected.

Now, since the problem with the performance is solved, we are good to go! But not so soon. Lately, I've hit another wall: filling the source with the data usually is what takes time and while pushing the hard work to another thread may give some more responsive UI, I have been (once more) challenged to look for a solution. The problem this time was the relatively slow response from the server and the data arrival was delayed due to many factors (net congestion, busy server, bad scaling, etc) so for the larger result set it would have rather disappointing results.

It may sound like a myth, but everyday Joe really does have kind of fate in the desktop apps when it's about speed. Things open instantaneously, response is short and in an event when there is a 1 second delay - it does not look nice. Trying to explain that the 10-year old MS Access app was much simpler, not scalable and insecure - doesn't improve the situation. Speed and response still remains an issue.

While that same everyday Joe "expects" the desktop app to fly, he/she has a completely different opinion when using the web based apps. The delays are expected (there were delays from the start), poor response even improves lately mostly due to the higher bandwidth or some AJAX here and there, but in essence, there are no complaints and things magically *work*.

One interesting point that we have had discussed within the team was how to tackle our problem of the slow server response while maintaining the UI speed and responsiveness? So, we thought about doing exactly what the web apps do when there are large result sets: page it!

Now, this was a challenge in the WinForm apps and the already familiar DataGrids (which are de-facto standard for the business desktop apps from the "battleship gray" era) were never designed to do so. Users always expected to see "everything" in a single shot, being able to sort, group, filter and whatever-else with a single mouse click. Adding paging to any of the DataGrid variants (third-party mostly) simply does not seem natural.

In WPF it seems like a good opportunity to re-arrange the user's opinion. While using some new ways of presenting the data that is far, far better (and different) from the battleship-gray style, we have a unique opportunity to bring results paging into the desktop apps. And the end-users seem not to complain! For them, a WPF app seems like a completely new experience and they are "easier" to accept new stuff. That is, provided that it still allows them to do their job.

CDNUG community event

2009-04-02T20:26:00.005+03:00

After so long time I've finally attended the latest CDNUG event on last Tuesday. It was good to meet and talk with Artemis and Evangelos.

Artemis spoke about Entity Framework and we all participated in the numerous demos.

I liked the exercises with the LINQ capabilities in combination with the Entity Framework.

XElement.Value and the new line hell

2009-03-14T20:04:00.007+02:00

Ever since I tried XElement, it always made me anxious when I had to workout few lines with the good, old System.Xml.XmlNode. Thanks to LINQ, we got these nice X* family of classes that are so much more easier and helpful.

Recently, we've moved the parts of our cache initialization methods to use XDocument and XElement instead. Some of the cache type classes contain multi-line strings usually displayed in a WinForms TextBox. Accessing the content of an element is simple as using the Value property.

textBoxNotes.Text = MyNode.Element("notes").Value;

In fact, everything works as expected, except the multi-line text. Property Value getter trims off the "\r" character from the string (which is required for the TextBox to actually show the text in the new line) and the lines appeared glued to each other in a single line.

Haven't found anything on this issue yet. It seems annoying to use:

Element("foo").Value.Replace("\n", "\n\r");

MVP award

2006-07-01T22:21:00.002+03:00

Just got an email with the subject "[MVP] Congratulations! You have received the Microsoft MVP Award".

At first I thought it was a spam and almost lost it! But then I read it again...

I'm still very surprised with the announcement and excited as well. The competency I've got the MVP award for is: Visual Developer - Client Application Development. This must be due to the activity in the our User Group and the subjects I used to cover in previous speaking engagements (WindowsForms and WPF).

MVP program offers many nice opportunities of connecting with fellow MVPs in the area and around the world. As an addition to that, you get the unofficial stuff directly from the Microsoft product teams and the ways to express your opinion.

Award is valid for one year and renewable based on the contributions to the community. I actually feel encouraged to do even more, as long as the time will allow. The ideas already started popping-up...

SQL 2005 Developers Marathon

2006-06-07T20:32:00.000+03:00

We had successful event yesterday in the Cyprus College campus (Nicosia) about MS SQL Server 2005 called SQL Marathon. Chad delivered few sessions that were about all new features of SQL Server 2005 and the audience was very satisfied with the content.

We are looking forward to organize some larger scale events in November, mostly related to WinFX, Vista and Office 12.

CDNUG event #9: Introduction to WPF

2006-03-15T21:47:00.001+02:00

I just returned home from tonight's User Group meeting where I spoke about the WPF (a.k.a. Avalon).

Must say that I'm not impressed how everything went, mostly because the demos I had prepared earlier didn't really work as expected. The content took me much more time than I ever thought it will and it might have been my mistake that I wanted to talk about EVERYTHING in a single hour. WinFX is a huge topic and the session supposed to be the intro to WPF - but at the end it took its toll. Few glitches with the January CTP of WinFX and Sparkle brought my demos to the ground but hopefully the audience got the idea what's hiding behind WPF and how powerful it is.

I was glad to see that there were lot of people interested in the subject - there were over 30 attendees - the most we had until now! Good lesson I learned from today is that I need to:

Prepare,
Prepare, and
Prepare.

That's it. Sessions need preparation, especially when working with the CTP stuff. I haven't tested the demos more than once each one and almost none of them worked. Another mistake was timing: I haven't timed myself well while preparing the content. It took me double time while presenting the material then while preparing it. In the upcoming months I hope to split the hard content in many small, specialized topics and present drill-down of each of the interesting features of WPF. As long as the time allows...

Quorum client - .NET 2.0

2005-12-23T17:27:00.001+02:00

With the extreme effort of our team, we have Quorum client fully converted to .NET 2.0 in just a few weeks time.

The story goes something like this:

Three weeks ago we started the conversion of Delphi .NET (WinForms) application to C# within Delphi2005 IDE.

One week later, the guys from the team moved to C# Express to validate final .NET 2.0 migration. Me - still in VS2005 Beta2, for additional verification.

Chad pointed us to the Empower program on Microsoft Partner website as an excellent start-up (Empower program provides - once approved - five MSDN Pro subscriptions for relatively small fee). We joined the Empower program and became approved in just a few days

MSDN package arrived in almost no time (5 days) and we were fully VS2005 Pro equipped.

Quorum client projects in Delphi are removed from SVN. We are fully in .NET 2.0!

Christmas holidays are ahead and things are moving nicely. Many things remain to be completed and we don't have hard dates, yet. But we are working hard and heading towards the RC1, probably during the beginning of 2006.

CDNUG Launch Event: Afterthoughts

2005-12-17T19:35:00.000+02:00

CDNUG Launch Event 2005 just happened yesterday in Hilton hotel, Nicosia. We had 72 attendees (peak) with 4 sessions of the Dev. track. It was excellent!

With the great help of Khaled Chebat we managed to organize and present Launch in CDNUG way. There were lot of developers interested in .NET and some of them took initiative to join the group. There will be some photos and comments posted on our website so keep checking for the updates. I'm using this opportunity to thank to Evangelos, Andreas and Cosmin for extreme effort and the time these guys put into the event and made it reality. Having that this was our first big event, we found out some things the hard way and learned a lot.

Special thanks goes to Khaled who presented slides for all sessions, plus whole single session between already tight flight schedule and almost no-sleep time.

Thanks to Microsoft and the rest of our sponsors who supported the Launch financially.

Finally, thanks to all members of CDNUG (and others as well) who attended the event.

Upcoming CDNUG event

2005-11-14T21:53:00.001+02:00

Today I was informed about the Launch Event we are about to organize on 15th of December in Hilton, Nicosia.

It will be half-day event to complement VS2005 Launch Events all over the world. Something that is officially planned to be done in Cyprus sometime in March - we consider to be too late for the developers here. Therefore, with help from INETA we will have a Launch Event organized solely by the CDNUG and supported by Microsoft and other few local companies.

I will be speaking about Smart Client application development using WinForms 2.0 and deployment with ClickOnce technology. We got plenty of support materials and I hope it will be an event to remember! We started the organization with Evangelos having overview on the whole operation. We have lot of things in mind and I will blog later about some, once we decide on details.

.NET 2.0

2005-11-04T20:57:00.004+02:00

Today we had an internal discussion between the team members about our future developments and how shall we proceed with new version of Delphi.

Borland Cyprus had contacted us and we were really interested about the offer they had for the upgrade from Delphi2005. But, we went further than Delphi upgrade issue in our discussion and tried to foresee our next steps. We came to a conclusion that with D2006 we'll be getting fixed D2005 with .NET 1.1 support and maybe few additional bells-and-whistles we honestly don't really use in our project. Because SpiderSlik client is full WinForms application, we unanimously agreed that we are going to move to C# and .NET 2.0.

For me personally, this was a sad moment. Delphi was my favorite language and IDE, I learned lot of things working with it and followed it since '95. On the other hand, I adore C# synthax and features. While using VS2005 Beta2 for few months I found it more stable than D2005 after 3 service packs! And .NET 2.0 brings bunch of new features that I consider extremely important for our future development(s). Another fact is that VS2005 will be out in a few days. .NET 2.0 is out since Monday. If we continue with Delphi we may wait for 2.0 support in summer next year. Whatever the case, Borland will always be 6-12 months behind MS when .NET is in question - and that's a fact.

We are aware that our complete client codebase will have to be rewritten into C# and some plans regarding the migration will be drawn soon. Guys seemed excited about moving but we still need to wait from the company management to make the final decision.

Team expansion

2005-09-30T20:42:00.000+03:00

We have decided to hire two new developers to join our team. Between more than a dozen of interviews, we agreed on two guys who suppose to start on Monday. I have to say that my expectations were to high, mostly because I never worked with another 4 developers in a team (yes, that's true - at least not face to face, in a single room!).

And as the story goes, one of the candidates gave up today by giving a phone call (three days before he should start!) that he got a job at the government. Oh boy! Nothing much to do about it now.

Anyway, we still expect one of the two chosen guys to show up on Monday and I believe he's worth being with us. Trying to encourage ourselves and continue with interviews but I'm really tired of it. IF any interesting CV shows up, we'll see. In the meantime - we gotta work to do!

CDNUG event #4

2005-09-08T19:23:00.000+03:00

Last night we had 4th group event in the offices of Microsoft Cyprus with two very interesting sessions.

Our new member, Cosmin Onea, spoke about Rocky Lhotka's CSLA Framework and explained the way Rocky used to solve common problems we (developers of the distributed systems) usually have. His session gave me few ideas to think deeper about and try to materialize some concepts I had earlier in mind. Will blog about that later, once I have more real stuff in my hands.

The second session was about "Application Setting the .NET way INI, Registry or XML" where Chad went through the options available to developers for storing application settings.

From other news, Chad announced his leaving (going to work for Microsoft) by giving up the User Group presidential position to Evangelos and I've been assigned the vice-president of the CDNUG. Cosmin has been assigned secretarial position but we will share the work, at least at the beginning. Find more info here.

.NET sockets

2005-08-20T08:03:00.002+03:00

Tonight I completed the change I've been working on for last few days. SpiderSilk client libraries have been changed from Indy to native .NET sockets (System.Net.Socket).

Previous network layer on the client has been implemented using Indy since the early beginning of the project. Indy still remains the core of the server side Connection framework and the stub of the protocol. Replacement came as the first step in the long-term plan to keep the SpiderSilk client as much as possible under the System namespace, that is - a pure .NET app. We are still using blocking sockets as the whole architecture has been built upon Indy - which, of course, uses blocking sockets. Performance wise there's no much difference, although I've noticed slight delay while establishing the connection at the start-up. Other than that - everything works perfectly.

CDNUG event #3

2005-08-05T09:53:00.000+03:00

On last Wednesday another CDNUG event happened, this time in Limassol (offices of InfoScreen) with small number of attendees but with two new members.

Chad spoke about ADO.NET datasets, WebServices and Atozed IntraWeb spanned into two hour-each sessions. As usual, you can find more info here.

Beta postponed

2005-07-16T18:50:00.001+03:00

Hot summer in Cyprus doesn't have to do much with the heat we have in the office. Mostly due to the work that is being packed up during my absence, additionally caused by decisions taken in direction other than SpiderSilk - by the company management.

The whole team will be transferred temporarily to another (web) project for some time (probably for a couple of months) meaning that SpiderSilk Beta won't be released in August as planned.

CDNUG event #2

2005-07-07T11:32:00.001+03:00

My first ever session, first show-up and performance just happened last evening. I suppose I did quite good although it's hard to judge from my point.

Mono is one of my favorite subjects and it seemed quite OK to speak about it. I investigated a bit to find out some weird & geeky stuff and the rest was already digested for sometime.

Chad assisted me by showing to the crowd how the projects under VS.NET compiled on Windows - were able to run on Linux (FedoraCore4) even using (at this time) not yet completed Windows.Forms namespace. There were few ohs we could hear from the crowd. Of course, you can see more here.

Back to normal

2005-06-18T15:52:00.002+03:00

My holidays finished, I had rough time during the wedding preparation and I feel like I need a real holiday now.

Beside Jagodina, I spent sometime in Cluj-Napoca, Romania, visited Belgrade, Novi Sad and Krusevac on few occasions and the rest I spent on the road. Yes, I added 5,5k km on my parents car in just a three weeks time! Figured out that I could have gone to Cyprus and back and with almost a thousand km over. That is - I don't want to see my car for next few weeks (unless I have to).

Luckily, Monday is public holiday so we will be off. Perfect timing to recharge my batteries and get so much needed rest. As expected, I have bunch of photos and videos from the wedding and I will post them to the web once I get some free time.

CDNUG was not as active as I thought it will be, mostly due to the trips abroad that all of us had. Preparation for the second event started and it's very likely that I will have my first session about Mono, with Chad's help (hopefully). Keep watching the Yahoo! group site.

Going off

2005-05-22T07:45:00.001+03:00

Officially, I'm on holiday since Friday. There is a bunch of things I have to go through in next few days. I am about to have a church wedding (and a small party for family and friends), therefore I am not sure how much of a holiday will that be but it's something that we are stressed about for last couple of months and definitely waiting to finish.

Due to some trips I'll have, tomorrow early morning I'm heading towards the Romanian Consulate in Belgrade to get an entry visa. Yes, visa regime has changed since last July so there are few more headaches I'll have to pass through. :(

Since I'll be more offline than online during my holiday, this blog might not be updated very often. So I hope to have great stories once I get back (June 17).

CDNUG first official community event

2005-05-20T20:34:00.001+03:00

First community event of the CDNUG just happened yesterday in Nicosia.

Thanks to the guys from Microsoft Cyprus who allowed us to host the premiere event in their premises. We had total of 13 members present on both sessions presented by Chad and the overall impression was great, at least to me. ;) You can have a look at the CDNUG official website (still under construction!) for more info and photos, of course. More interesting workouts are planned to be performed during this summer so keep watching.

First CDNUG meeting

2005-05-06T09:58:00.002+03:00

First meeting of the Cyprus .NET User Group just happened yesterday in a nice Mexican restaurant in Limassol. Chad, Evangelos and me - that was about it.

We drew few main points regarding the UG establishment and future expansion. We also agreed on frequent informal meetings to discuss and plan bigger events that should take place every 3~4 months. Chad was eager to do the initial presentations, which will be of great help for the UG and attractive to the new members.

As we speak, I'm trying to spread the movement to other developers I know. Next week we agreed to meet in Nicosia and have another "unofficial" meeting with few more members, hopefully. Stay tuned for more news!

[UPDATE]

Chad posted a message with notes from yesterday's meeting here.

Cyprus .NET User Group

2005-04-28T16:32:00.002+03:00

Today I received an invitation from Chad to form a user group related to .NET technologies. We came up with the Yahoo! group for the start and called it CDNUG targeting all .NET users in the island of Cyprus.

I was thrilled with the idea so I joined the same moment. I did spread the information to other members of our team as well, but I'm not aware of their reaction yet. If everything goes as planned with the CDNUG, occasional meetings (monthly community nights) are "on the horizon" and probably some conferences/events in the future.

If you live in Cyprus + anyhow related to .NET and would like to become member, please do so. We are glad to accept new members and grow the community.

Desktop Alert

2005-03-24T08:25:00.000+02:00

I was quite bored last night looking at the messages receiver implemented in Q that I decided to do something about it.

Having the exact-moment experience, I really liked the way Outlook (2003) displays alerts once new email is received using non-distracting notification window near the system tray. There is also other bunch of apps showing the similar functionality (IMs, GMail alert, etc) so I thought of doing something similar to that.

The result was a plain, borderless form that mimics animation using combination of Timers and Opacity property, auto-hides after the specific number of seconds. The window is not sizable at run-time and since the message body could be longer than the space provided, I left the "clickable" label that will call good, old MessageBox.Show() method - displaying whole message body.

Even though the Alert window adds a bit of spice to the boring "battleship gray" structure, messaging in Q will have to be enriched with other functionalities in the future. For the time being, I just keep writing notes about it.

SpiderSilk receives a product name

2005-03-23T10:12:00.002+02:00

Yes, that's right: our flagship product got a public name - InfoScreen Quorum.

After bunch of ideas, including some mythological names from Greek history, we settled down on Quorum.

It's a word from Latin language and it is primarily used in Corporate/Legal sector that SpiderSilk is going to cover: Annual General Meetings (AGMs) and other meetings as well - where quorum of present members is important to make the taken decisions valid.

As the development process has been re-scheduled, we are in final phase of polishing both client and server and our QA dept. have started the extensive testing process.

My first blog entry - Grand opening

2005-01-15T13:50:00.002+02:00

Well, the time has come - and finally I found some free of it to setup this Blog...

After some time of browsing I found this neat blog script, and believe it or not - I've installed it in less than 2 minutes. Possibly because we already had configured system the way that Serendipity requires.

From now on, this will be the place where different ideas and point's of view of an InfoScreen blogger will be reflected.

[UPDATE: 21 February 2008 - 14:10]

I have finally managed to set myself on the track of blogging... again.

For that reason I am moving my previous blog entries from a custom, serendipity based blog on my company's website to blogger.com.

Above was my first post ever in the blogoshpere.