In VS2010, when the Data Sources Window is used to generate the UI, the generated XAML injects design-time information so that the Binding Builder can be used to create bindings for the UI controls. But if your application was written in Visual Studio 2005 or 2008, or you used the XAML Editor, the Designer or Expression Blend without the Data Sources Window, your coding style is to assign the DataContext in code and not data bind to CollectionViewSources in your XAML, then you won’t be able to take advantage of the new Binding Builder. How to Enable Using the Binding Builder in WPF and Silverlight Applications by Karl Shifflett to the rescue – it demonstrates the simple requirements to enable you to use the new Binding Builder in a variety of scenarios like the ones mentioned above.
In his Styling A ScrollViewer/Scrollbar In WPF article Sacha Barber explains how to do exactly what the article’s title claims. :)
WPF: Data Virtualization article at CodeProject shows a different approach to the data virtualization for WPF ItemsControls – a collection class providing data virtualization with large data sets.
WPF : A graph control by Sacha Barber at CodeProject is a very nice article showing how to build a graph control in WPF, in a very detailed and elaborated way. The control looks great, by the way :) .
There is one severe problem with video playback in WPF/Silverlight that, for some reasons unknown to me, is getting very little (almost none) attention from both the community and Microsoft. Basically, it boils down to WPF being absolutely unable to properly play video content. Let me explain by using the following diagram:
First line shows video frames as they are in the video content. Second line depicts variable frame rate of the WPF renderer – as you know, WPF is changing the frame rate dynamically, and CPU load will affect frame rate too. There are two possible outcomes:
This is a bit oversimplified picture, but good enough for our purpose. In reality, the resulting on-screen picture will depend also on the screen refresh frequency, but artifacts will be more or less the same. In both cases the video playback it totally unacceptable though.
The issue is very serious, and, unfortunately, it is unsolvable in terms of today’s WPF. I think it will be not solved in the near future either, as solving it would require WPF to adopt constant-frame rate rendering paradigm, and synchronizing it with the display refresh rate. This is not likely to happen, as it is a drastic change to the fundamentals of WPF, and, at the same time, it will waste resources in non-video related applications (now WPF can decide what frame rate it will use, and can dynamically change it, e.g. dropping frame rate for “still” scenes and increasing it when animations start).
In our software we had to go through a lot of extra pain to “overcome” this issue – we render video using DirectShow by incorporating Win32 host into our WPF application and implement all kinds of “tricks” to allow WPF content to get into the video window airspace (to display OSD’s, menus, etc.) by using e.g. clipping regions (say Goodbye! to transparency though). There are a few third party projects out there (WPF MediaKit by Jeremiah Morrill is an excellent example) that allow one to mix DirectShow and WPF, but none of them will fix the above mentioned issues, as the resulting picture is rendered by WPF renderer and all the artifacts will be there still.
Probably, for majority of people this is not really an issue (at least until you point them to it; after that they can see it on their own and they become very annoyed), especially if you are playing some kind of home-made content from the YouTube (although YouTube has HD content nowadays too), but it is completely unacceptable for people at least somehow concerned about the video playback quality. DVD/DivX player costing $30 will not have these problems, so it is difficult to explain why $1000 machine (33 times more expensive!!!) cannot produce even remotely as good video playback on $2000 HD TV set.
In addition to these video playback problems, WPF on XP suffers from the tearing issue not only during video playback, but also during “normal” WPF animations. And this has even more profound effect, as it makes it impossible to implement animated WPF applications on XP.
Microsoft’s reaction to the tearing issue on XP is problematic. We have tried to approach them via all possible channels – Microsoft Connect program, Microsoft Metro program, newsgroups, personal contacts, everything. They either deny the issue, or say that it is unsolvable for XP in general case, so they are not going to solve it (but they could easily solve it for something like 95% of all XP installations by solving it at least for ATI and Nvidia cards), or they say that they will not solve it for XP anymore, as XP is not available so nobody cares. And this last reaction is problematic again, as the issue is present not only on Windows XP Home/Pro, but on Windows XP Embedded and Windows Embedded Standard as well. These OS’s will be around for some time still, and Windows 7 Embedded will not come before 2010 and, being Vista-based, will be a resource hog – something not necessarily good for embedded system.
It seems that Sun can say now, “rumors about my death were greatly exaggerated”. Recently they rather quietly released JavaFX – a rich client platform (what has happened to thin client dreams of Sun and alike? huh? ;) for creating and delivering rich Internet experiences across “all the screens of your life” (they are using this phrase all over the place, and it sucks, to be honest, but go figure).
From what they show in their videos, it looks rather like WPF/Silverlight for Java. In other words, it is the presentation layer for the Java platform. Performance-wise it looks rather good (OK, no idea what hardware was running those demos). For example, they were playing 9 (yes, nine!) video streams simultaneously, but then, who the f#$k needs 9 videos playing at the same time!? It is the same f#$*%ng old useless BS that Microsoft is showing all the time! Of course, it remains to be seen if it can play all this video content without framerate issues that plaque WPF/Silverlight. JavaFX Script is a declarative scripting language behind JavaFX.
Sun is promising to make JavaFX multiplatform, capable of running on desktop, mobile, TV and other Java-enabled consumer platforms, but so far they have desktop version only. Then, as far as I understand, development tools are not necessarily ready yet (judging from their sentence “JavaFX technology will provide a suite of tools and authoring solutions that enable unprecedented collaboration between designers and developers”). If they will deliver all these promises, Microsoft might get into deep trouble with WPF, as Java’s inability to provide good UIs were one of the main reasons why many were choosing .NET over Java on the client side (I am not discussing platforms – .NET 3.5 vs Java 6 – just presentation parts). What Sun has already made right, in my opinion, is their selection of Adobe PhotoShop and Illustrator as a designer tools, as these are light-years ahead of Microsoft Expression Designer.
Future will show, what will come out of all this, but the good point is that Microsoft will get some competition in this field, and might eventually do something to fix its platform’s shortcoming (though unlikely – so far they are taking extremely defensive and ignorant stance regarding WPF/Silverlight problems).
We have recently purchased PreEmptive Solutions Dotfuscator (which sounded like a good idea when we were making decision about it), but to be honest I am not very happy about it: it cannot properly handle WPF projects and you have to perform a lot of “voo-doo dances” to get at least some protection there (and all that while costing s|-|1t-load of money). This pushed me to do a new round of evaluations of competing products, and I have found few that are really interesting:
It seems that to get decent level of protection we will have to use either {smartassembly}, or both .NET Reactor and {smartassembly} (in case {smartassembly} would be not able to provide the same protection level for “normal”=non-WPF assemblies as .NET Reactor does – remains to be seen).
Webcam control with WPF or how to create high framerate player with DirectShow by using InteropBitmap in WPF application by Tamir Khason shows how to do exaclty what it claims to show :) in a way alternative to what Jeremiah Morrill is proposing (now, I do not have an opinion as of which is better or worse – they both have their uses).
Side Note Unfortunately, you cannot play decent quality video in WPF application (meaning in WPF “airspace”) no matter what you do – it has to do with non-constantness of the WPF rendering frame rate (and, on XP, add here WPF tearing artefacts), and I do not see how it can be fixed in the future as this problem is rooted extremely deeply in the core of WPF rendering pipeline. Microsoft knows about this issue, but does nothing to fix it.
Crack.NET is a runtime debugging and scripting tool that gives you access to the internals of a WPF or Windows Forms application running on your computer. It nicely rounds the Snoop and Mole for Visual Studio group, as it allows you to “walk” the managed heap of another .NET application, and inspect all values on all objects and types. In addition, you are able to write and execute IronPython scripts that run inside the target application.
Josh Smith is the author, and has a nice introductory page for the tool.
Dr. WPF has a great series titled ItemsControl: A to Z. Following parts are available so far:
There is version 4 of the Lester Lobo‘s XamlPadX – a replacement for XamlPad with few interesting add-ons like Command Interpreter, ability to view control styles, color selection, etc.
As expected (even earlier than expected, to be honest), today Microsoft released Silverlight 2 and Expression Blend 2 SP1.
Had no time to blog – work really takes all my time nowadays (and “nowanights” too :)…
Microsoft has finally released a newer version of Expression Blend. Now it is called Expression Blend 2 SP1 Preview or Expression Blend 2 SP1 RC Preview, depending on where on Microsoft’s site you are reading it, hinting that we will likely get the final release version rather sooner than later (in a month or two, who knows?). This is the version that marks the end of Expression Blend 2.5 CTP – Microsoft will not release newer versions of 2.5 CTP anymore; instead, all 2.5 features migrated to Blend 2 SP1, which is not bad IMHO.
I had not much time to play with it so far, but what I have seen looks really promising. For example, Blend finally stopped crashing all the time in case there were errors in XAMLs (or rather in code-behind); now it is displaying meaningful error messages about these problems, so you finally get a chance to fix it. Of course, there are still many problems which Microsoft most likely will not fix in this release anymore. For example, the Resources pane really sucks big time: if you have many resource files (and you have them if you are skinning your app), it is virtually impossible to navigate in them – they are sorted in weird order known only to Microsoft itself (or, maybe, it is just random?), and there is no way to do anything about it, e.g. sort them in alpha order.
In any case, it is really big step in the right direction. I would recommend to move to 2.0 SP1 ASAP in case you are using 2.5 CTP and developing WPF applications (cannot say about Silverlight/Silverlight 2 as I am not using those).
Dr. WPF published Introduction to D3DImage on CodeProject. The release of .NET 3.5 SP1 made possible a whole new level of WPF-DirectX interop: a custom DirectX scene can now be composed with a WPF scene using the new WPF’s D3DImage feature.
OMFG! One guy (OK, OK, he partially reused the work of another guy) made what whole Expression team was unable to do for ages – IntelliSense for Expression Blend add-in! WOW! Works in Blend 2.5.
Well, Josh Smith is always producing good stuff: his Using RoutedCommands with a ViewModel in WPF at CodeProject is really cool!
Found Weather Reader User Control (on CodePlex), that has the functionality of Vista weather gadget. The control parses a XML weather feed from the Internet and updates an object model that is data bound to the UI. The design is extensible and can be adapted to any general feed with minimal changes.
WPF Runtime Localization article on CodeProject describes one way to do it. Interesting approach is to use WPF Localization Extension available freely on CodePlex. And then there is an article that goes in the same direction: WPF Localization – On-the-fly Language Selection.
WPF blogs from Microsoft and ex-Microsoft guys/gals primarily (as well as guys that know their way around the Microsoft):
And here are blogs by ex-Microsoft people (sad, that they are not at MS anymore):
Channel 9
Other blogs:
