The problem: you create an abstract class that inherits from something that can be designed in Visual Studio, like Form. Then you inherit another class from this abstract one. And when you get into the Visual Studio designer you see a nice colorful error message: The designer must create an instance of type 'bla bla bla' but it cannot because the type is declared as abstract.

The solution is detailed in a post of Brian Pepin: use the TypeDescriptionProviderAttribute decoration on the abstract class in order to tell .Net (thus to Visual Studio) what concrete type to declare and instantiate should the need arise.

Update: Brian's article is no longer available. I will update the link as soon as possible. Meanwhile, try this article from Microsoft.

Update: I have found the original article somewhere else and relinked it. Also, check out the fourth comment on this entry, where TrevDev links to a Microsoft Connect bug on the TypeDescriptorAttribute which suggests the attribute is not used correctly. That probably explains why people on VS2008 have problems, while the solution works on VS2005.

Now, all you have to do is read the post in question, with one reserve. The blog entry (and some other pages I have found on the net) say that this only works for Whidbey (VS2005), but I am using VS2008 and it worked just as well. However, for a second opinion try this CodeProject article that uses a little conditional compiling trick to switch from abstract classes with abstract methods and properties to normal classes with not implemented classes and methods based on debug/release modes. I kind of dislike the approach, mostly because it needs more effort to implement it, but it could help people that have this problem and maybe use some other IDE other than VS2005 or VS2008.

Just yesterday I was struggling with the same issue, only this facette of it seems like a completely different bug. You see, I added this control to the library and everything worked fine EXCEPT the visual designer. It is known that the Visual Studio 2008 WPF designer is not the best possible piece of software, but this was one of those errors you don't know where it comes from.

So, let's take it from the beginning. I had something like
<HierarchicalDataTemplate DataType="{x:Type Code:League}" ItemsSource="{Binding Path=Divisions}">
<TextBlock Text="{Binding Path=Name}"/>
Somewhere in the Window declaration there was a
which is the namespace of the test application for the control in the library.
The application worked, but in the designer an error like "Type reference cannot find public type named 'League'.".

Many people gave the solution to remove the name of the assembly in the namespace declaration. So If I had something like "clr-namespace:MyControls.Desktop.Code;assembly=MyControls" and it was the current assembly, I should just remove it. Well, it wasn't the case here, was it?

In the end I found the solution here. You see, even if the assembly name was not specified, it was implied! And even if it was an application, not a library, it still was an assembly. And the Application name was... something with spaces in it!!

So, again, just go to the Project properties and change the Assembly name to not have spaces!

So, I had just wasted a long time being stupid about a user control, but I had finally fixed everything and I was willing to try it out. Initially I had tested it by directly entering it in XAML, but now I wanted to add it to the toolbox and drag and drop it to the WPF form.

First I got an error like "The following assemblies are installed SDK assemblies but could not be shown in the customize toolbox dialog because they are missing one or more components. Please make sure that all necessary libraries are available:" and then Microsoft.Ink.dll. It didn't seem to do anything bad, but I googled it anyway. It seems that a lot of people had this problem. The only solution was to actually close Visual Studio and then open it again. Other people reported more complicated issues like Visual Studio suddenly closing or showing a lot more libraries and doing it every time. This could help in that case: 363321. Choose Items in Toolbox causes Visual Studio 2008 SP1 to crash.
It also may be linked to the Visual Studio 2008 SDK, which I had recently installed.

Anyway, after that problem was solved, I proceeded on loading my WPF user control library by clicking Choose Items on a new Visual Studio toolbox tab and then browsing the DLL. Boom! "There are no components in 'something.dll' that can be placed on the toolbox.". That is because you must FIRST select the WPF Components tab in the Choose Items dialog, THEN click Browse. If you have Visual Studio 2005 you are out of luck, you don't even have the WPF components tab and the only way to do it is use the XAML editor.

Two short points I'd like to make about working with WPF in Visual Studio 2008:
  1. In order to see Binding errors, you need to open the Output window while the app is running, since any binding error is silently dropped, but displayed there. There is also a Binding property called FallbackValue which you can set to "ERRRROOOORRR!!" :)
  2. XML files are seldom unformatted or having weird spaces and extra lines. Yet, there is not context menu for XML editors like the Format in ASP.Net as*x files. However, the option (and many more) is available in the Edit -> Advanced menu.
    • Format entire document: Ctrl+K, Ctrl+D
    • Format selection: Ctrl+K, Ctrl+F
  3. Unfortunately, some of the useful commands are just set up in the Options menu, like what to do with extra lines. So go to Tools -> Options -> Text Editor -> XAML -> Formatting.
    • To set it so that the XML is auto formatted at completion of start/end tag or when pasting code, go to the General option
    • To get rid of extra empty lines, go to the Spacing option and choose either Collapse multiple empty lines in content to a single line or Remove empty lines in content

There are two things you need to do. First, set the project as having a neutral language. This is done in Visual Studio 2008 by going to the project's properties, selecting Application, clicking on Assembly information and setting the language. However, it doesn't set an UltimateResourceFallbackLocation. So you have to do it manually, by editing the Properties\AssemblyInfo.cs file and adding
[assembly: NeutralResourcesLanguageAttribute("en-US", UltimateResourceFallbackLocation.Satellite)]

The second thing is rather dumb. I haven't found ANY way to do it from Visual Studio. I just edited the csproj file manually. It needs
set in (under, actually) every <PropertyGroup> in it.

What that does is create a language folder in the bin directory when compiled with a localizable resource file. Using the locBaml utility in the Windows SDK you can turn a resources.dll in the language folder into a CSV, then back into a dll like this:
LocBaml /parse ProjectName.g.en-US.resources /out:en-US.csv
LocBaml /generate ProjectName.resources.dll /trans:fr-CA.csv /cul:fr-CA

You will not find locBaml in the Windows SDK folder except maybe as a sample project. The sample project can be downloaded here. Don't forget to compile it!

Some other useful links:
WPF Localization
Localizing WPF Applications using Locbaml
LocBaml + MsBuild + ClickOnce Deployment

Rick Strahl presents an easier and better alternative by using normal resx files! I don't want to copy (too much) from his post, so just read it:
Resx and BAML Resources in WPF

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I was just installing a new system, with all the necessary tools of the trade (Visual Studio(s), Sql Server, etc) and after I've installed VS2005 I noticed that there was no entry for the Business Intelligence Studio. I've tried all kinds of "solutions" on the net, varying from using some complicated command line to running vs_setup (exe or msi) or even reinstalling everything (which I refused to do).

In the end the problem was simple enough: Visual Studio installed some SQL Express version and the SQL Server 2005 setup thought I already had Business Intelligence Studio installed, so it never did reinstall it. The solution is to run this command line:
on the SQL 2005 installation kit.

  • the parameters MUST be upper case, otherwise it will not work
  • it may be that only one of those parameters is actually necessary, but I have tried them both, anyway

Well, you might laugh out loud when you read this, but it is an achievement for me. I wanted to update a table (table A) which had a connection to another table (table B) through a many to many table (table A2B). I had changed A2B to link A to a new table C. I wanted to reflect that change in my Entity Model.

So the first step was to right click on the model and do an "Update Model from Database". Then went through all the steps and clicked Finish. Now entity A has both a collection of Bs and a collection of Cs. I wanted to delete the B collection but, to my chagrin, no delete option was available.

The epiphany came when I managed to select the graphical link from entity A to entity B. The link has the delete option! Which, I have to admit, does make sense. So whenever you want to remove an association between entities... well, select the association and delete it, not the entity properties.

It has been a pain in the ass for me to use the graphical designer in Visual Studio. Instead I have used writing the markup of web pages and controls using the keys. It went several times faster, but still, it lacked the speed of any text editor I have ever seen. Moving up, down, left, right with the keys would make the system lag, jerk, etc. It was never too annoying to investigate until today.

What happends is that whenever you work in a VS window, it sends events to just about everything on the screen. The more windows you have open, the more it lags. And the culprit for this particular problem: the Properties window. Every time I was moving with the keys it tried to update itself with the information of the object I was moving over. Closing the Properties window fixed it! \:D/

I've stumbled upon a little VS2008 addon that I think could prove very useful. It's called Clone Detective. Here is how you use it:
  • Make sure VS2008 is closed
  • Download and install the setup file
  • Additionally the source is freely available!
  • Open VS2008 and load a solution up
  • Go to View -> Other Windows -> Clone Explorer
  • Click the Run Clone Detective button

Now you should be able to see the percentage of cloned code in each file and also see the cloned code as vertical lines on the right vertical border next to the code.

I am going to quickly describe what happened in the briefing, then link to the site where all the presentation materials can be found (if I ever find it :))

The whole thing was supposed to happen at the Grand RIN hotel, but apparently the people there changed their minds suddenly leaving the briefing without a set location. In the end the brief took place at the Marriott Hotel and the MSDN people were nice enough to phone me and let me know of the change.

The conference lasted for 9 hours, with coffee and lunch breaks, and also half an hour for signing in and another 30 minutes for introduction bullshit. You know the drill if you ever went to one of such events: you sit in a chair waiting for the event to start while you are SPAMMED with video presentations of Microsoft products, then some guy comes in saying hello, presenting the people that will do the talking, then each of the people that do the talking present themselves, maybe even thank the presenter at the beginning... like a circular reference! Luckily I brought my trusted ear plugs and PDA, loaded with sci-fi and tech files.

The actual talk began at 10:00, with Petru Jucovschi presenting as well as holding the first talk, about Linq and C# 3.0. He has recently taken over from Zoltan Herczeg and he has not yet gained the necessary confidence to keep crouds interested. Luckily, the information and code were reasonably well structured and, even if I've heard them before, held me watching the whole thing.

Linq highlights:
  • is new in .NET 3.0+ and it takes advantage of a lot of the other newly introduced features like anonymous types and methods, lambda expressions, expression trees, extension methods, object initializers and many others.
  • it works over any object defined as IQueryable<T> or IEnumerable (although this last thing is a bit of a compromise).
  • simplifies our way of working with queries, bring them closer to the .NET programming languages and from the just-in-time errors into the domain of compiler errors.
  • "out of the box" it comes with support for T-Sql, Xml, Objects and Datasets, but providers can be built (easily) for anything imaginable.
  • the linq queries are actually execution trees that are only run when GetEnumerator is called. This is called "deffered execution" and it means more queries can be linked and optimised before the data is actually required.
  • in case you want the data for caching purposes, there are ToList and ToArray methods available

Then there were two back-to-back sessions from my favourite speaker, Ciprian Jichici, about Linq over SQL and Linq over Entities. He was slightly tired and in a hurry to catch the plain for his native lands of Timisoara, VB, but he held it through, even if he had to talk for 2.5 hours straight. He went through the manual motions of creating mappings between Linq to SQL objects and actualy database data; it wouldn't compile, but the principles were throughly explained and I have all the respect for the fact that he didn't just drag and drop everything and not explain what happened in the background.

Linq to SQL highlights:
  • Linq to SQL does not replace SQL and SQL programming
  • Linq to SQL supports only T-SQL 2005 and 2008 for now, but Linq providers from the other DB manufacturers are sure to come.
  • Linq queries are being translated, wherever possible, to the SQL server and executed there.
  • queries support filtering, grouping, ordering, and C# functions. One of the query was done with StartsWith. I don't know if that translated into SQL2005 CLR code or into a LIKE and I don't know exactly what happends with custom methods
  • using simple decoration, mapping between SQL tables and C# objects can be done very easily
  • Visual Studio has GUI tools to accomplish the mapping for you
  • Linq to SQL can make good use of automatic properties and object initialisers and collection initialisers
  • an interesting feature is the ability to tell Linq which of the "child" objects to load with a parent object. You can read a Person object and load all its phone numbers and email addresses, but not the purchases made in that name

Linq to Entities highlights:
  • it does not ship with the .NET framework, but separately, probably a release version will be unveiled in the second half of this year
  • it uses three XML files to map source to destination: conceptual, mapping and database. The conceptual file will hold a schema of local object, the database file will hold a schema of source objects and the mapping will describe their relationship.
  • One of my questions was if I can use Linq to Entities to make a data adapter from an already existing data layer to another, using it to redesign data layer architecture. The answer was yes. I find this very interesting indeed.
  • of course, GUI tools will help you do that with drag and drop operations and so on and so on
  • the three level mapping allows you to create objects from more linked tables, making the internal workings of the database engine and even some of its structure irrelevant
  • I do not know if you can create an object from two different sources, like SQL and an XML file
  • for the moment Linq to SQL and Linq to Entities are built by different teams and they may have different approaches to similar problems

Then it was lunch time. For a classy (read expensive like crap) hotel, the service was really badly organised. The food was there, but you had to stay in long queues qith a plate in your hand to get some food, then quickly hunt for empty tables, the type you stand in front of to eat. The food was good though, although not exceptional.

Aurelian Popa was the third speaker, talking about Silverlight. Now, it may be something personal, but he brought in my mind the image of Tom Cruise, arrogant, hyperactive, a bit petty. I was half expecting him to say "show me the money!" all the time. He insisted on telling us about the great mathematician Comway who, by a silly mistake, created Conway's Life Game. If he could only spell his name right, tsk, tsk, tsk.

Anyway, technically this presentation was the most interesting to me, since it showed concepts I was not familiar with. Apparently Silverlight 1.0 is Javascript based, but Silverlight 2.0, which will be released by the half of this year, I guess, uses .NET! You can finally program the web with C#. The speed and code protection advantages are great. Silverlight 2.0 maintains the ability to manipulate Html DOM objects and let Javascript manipulate its elements.

Silverlight 2.0 highlights:
  • Silverlight 2.0 comes with its own .NET compact version, independent on .NET versions on the system or even on operating system
  • it is designed with compatibility in mind, cross-browser and cross-platform. One will be able to use it in Safari on Linux
  • the programming can be both declarative (using XAML) and object oriented (programatic access with C# or VB)
  • I asked if it was possible to manipulate the html DOM of the page and, being written in .NET, work significantly faster than the same operations in pure Javascript. The answer was yes, but since Silverlight is designed to be cross-browser, I doubt it is the whole answer. I wouldn't put it past Microsoft to make some performance optimizations for IE, though.
  • Silverlight 2.0 has extra abilities: CLR, DLR (for Ruby and other dynamic languages), suport for RSS, SOAP, WCF, WPF, Generics, Ajax, all the buzzwords are there, including DRM (ugh!)

The fourth presentation was just a bore, not worth mentioning. What I thought would enlighten me with new and exciting WCF features was something long, featureless (the technical details as well as the presenter) and lingering on the description would only make me look vengeful and cruel. One must maintain apparences, after all.

WCF highlights: google for them. WCF replaces Web Services, Remoting, Microsoft Message Queue, DCOM and can communicate with any one of them.

FxCop is a free Microsoft utility that analyses compiled .Net code and makes suggestion based on rules, may them be design, security, performance of company policy rules.

The first problem is that you can only use it on compiled code. That means executables and DLLs. But what about ASP.Net 2.0? It doesn't build a DLL anymore, like 1.1 did. How can one use it? I have built an application (one that you will have to message me to send to you) that takes the project name as a parameter and then creates an FxCop project file with the DLLs from the site bin folder as reference DLLs and the DLLs from the Asp.Net temporary folder of that project as analysis targets. That means that you can also use it for ASP.Net now.

The second problem is that FxCop is now part of Team System, the overpriced and overhyped version of Visual Studio, and any attempts to use it with the Standard or Professional versions are cumbersome and undocumented. Siderite to the rescue! Here is a quick way to integrate FxCop as an external tool to Visual Studio and use it for either Console and Windows Forms applications or Asp.NET sites.

Step 1. Download FxCop. The latest version is 1.35, but there is also a 1.36 beta available that knows about lambda expressions and stuff like that.
Step 2. Get from me the FxCopAspNet application (completely free and with source), or build your own. Here is a possibly working link for it: at MediaFire.
Step 3. Open Visual Studio, go to Tools/External Tools and add two FxCop entries:
- FxCop [use C:\Program Files\Microsoft FxCop 1.36\fxcop.exe as Command, "$(TargetPath)" as Arguments and C:\Program Files\Microsoft FxCop 1.36 as Initial Directory]
- FxCopAspNet [use C:\Program Files\FxCopAspNet\FxCopAspNet.exe as Command, "$(ProjectFileName)" as arguments and C:\Program Files\FxCopAspNet as Initial Directory]
Step 4. Just open your web site or application in Visual Studio, compile it, then click on the FxCop item that applies.

Now, this is not meant to be a tutorial on FxCop, here are some links that might enlighten people:
Download FxCop 1.36 Beta
Download FxCop 1.35
Open Source FxCop Integration Add-in for Visual Studio 2005
How to copy the necessary files from Team System to Visual Studio 2005 Professional to make integration work
Use FxCop from your own code
A small tutorial
FxCopUnit, FxCop testing unit project
Video on how to create your own FxCop rules

There are a myriad rules included in the default installation of FxCop, some of them are just annoying, like some naming rules or some telling you you shouldn't raise Exceptions just objects inherited from Exception, but some are pretty good. A lot more can be found on the Internet and now, with the integration in VS Team System, I expect a lot more to pop-up.

This book is written by a guy that made a small company dedicated to programming with free tools. Thus, it tries to show how to debug ASP.Net assuming that you come from an ASP background and that you don't have Visual Studio .Net. So I don't think I have to tell you how much useless information there is in there. It even covers programmatic code tracing.

That doesn't mean it is a bad book, just useless for me. If you expect some wonderful debugging frameworks or code structure that would allow you to easily debug your applications, then this book is not for you. Not to mention that at the time it was written, Visual Studio 2005 was not out yet.

Bottom line: just a hands on approach and some Google when you meet problems will solve any problems that are solved by this book.

You may have noticed that in debug mode, in Visual Studio, you have a little magnifier glass next to some of the variables in Autos, Local or Watch debug windows. Once you click on it, you get to visualize your data in a more comprehensive way. A good example are the DataSet Visualizer or the DataTable Visualizer which show you in a normal DataGridView a DataSet or DataTable.

The good news is that you can build your own visualizers and that in a very simple way. Here are the quick steps to achieving this, followed by some links to other people detailing:

  1. Create a new Visual Studio class library project
  2. Add a reference to the Microsoft.VisualStudio.DebuggerVisualizers library you can find directly in the .NET tab
  3. Go to Add New Item and choose Debugger Visualizer. That will create a small class for you with ToDos and stuff like that. What is important is that you don't really need to declare the Type of your data object in the class, as suggested by the template.
  4. Remove everything from the class except the override of the Show method
  5. Change the Show method in order to use your own data type.
  6. Add a reference to System.Windows.Forms
  7. Add a Windows Form to your library and make it display your data the way you like it
  8. Add the following lines to decorate the namespace of your visualizer class:

[assembly : DebuggerVisualizer(typeof (--YourVisualizer--),
Target = typeof (--Your Type--),
Description = "--Your Type-- Visualizer")]
namespace ...

Warning: use a different description from whatever default or own visualizers that are already there. Use stuff like "Siderite's DataTable Visualizer" not "DataTable Visualizer", since there is already an out-of-the-box visualizer with the same name and you won't get to see yours.

Now compile. The resulting DLL can be either copied in My Documents\Visual Studio 2005\Visualizers in this case any contained visualizers will be available only to that user or in C:\Program Files\Microsoft Visual Studio 8\Common7\Packages\Debugger\Visualizers to make the available to all users.

That is it! Now links to others explaining in more detail:
Writing a Visualizer at MSDN
Post on Debugger Visualizers from 4GuysFromRolla
Julia Lerman on Debug Visualizers

A problem with this solution is that the debugger visualizer expects your target type to be ISerializable. But what if it is not? The solution is to add another parameter to the DebuggerVisualizerAttribute like this:
[assembly : DebuggerVisualizer(typeof (--YourVisualizer--),
typeof (--YourVisualizerObjectSource--),
Target = typeof (--Your Type--),
Description = "--Your Type-- Visualizer")]
namespace ...

You see, the debugging is done through communication between a debuggee and a debugger. The VisualizerObjectSource is the debugee and the default one tries to serialize the target object and send it to the debugger. What you have to do it create your own class, inheriting from VisualizerObjectSource and overriding public void GetData(object target, System.IO.Stream outgoingData). This method has access to the actual object, so you can transform it into any other object, one that can be serializable.

A simple example is a DataView or a DataRow. You take the DataRow, you add it to a Table and you return the DataTable, which is serializable.

Another issue you might stumble upon is a weird Access Denied error for the DLL containing the visualizers, especially after adding a VisualizerObjectSource to the library. The solution is to add trust level to full to the site you are debugging. I am looking for a more elegant solution, but so far what you have to do is add this to the web.config of the site you are debugging:

<trust level="Full" originUrl="" />

More links, specific to this update:
RemoteObjectSourceException: Graphics is not marked as serializable
Visualizers For Web Debugging

In order to debug SQL many people open new windows in Query Analyser or Management Studio trying to see where the errors come from and opening transactions and rolling them back and basically be miserable.

Yet, even from Microsoft SQL 2000 stored procedures had debug support. You would use Query Analyser, open Object Browser, right click a stored procedure and select Debug.

However, in SQL 2005 you can't do that anymore. Query Analyser is no longer available, the Management Studio doesn't have debug options and the SQL 2000 Query Analyser doesn't allow you to debug stored procedures on SQL 2005 servers. But there is support for SQL debugging in Visual Studio .NET, in the Professional and Team versions. Let me rephrase: If you have the Express or Standard editions you are out of luck. No SQL 2005 debugging for you. I did some queries on the web searching for third party sql debuggers, maybe something from Microsoft, like their Javascript Debugger (which works better than the in-built javascript debugging in Visual Studio, btw)

There are some ugly problems that may occur:

Maybe others. In this case, please let me know so I can update the post. Other people need help too, you know?

Even so, SQL debugging is not as straight forward as usual debugging. From the Microsoft entry on How to debug stored procedures in Visual Studio .NET I quote the Limitations of stored procedure debugging:
  • You cannot "break" execution.
  • You cannot "edit and continue."
  • You cannot change the order of statement execution.
  • Although you can change the value of variables, your changes may not take effect because the variable values are cached.
  • Output from the SQL PRINT statement is not displayed

While working on a Windows app that used Crystal Reports 9 with Visual Studio 2003 on .NET 1.1 I've stumbled upon a problem. For no apparent reason, the saving of a report took minutes rather than seconds, the .cs file associated with the report sometimes disappeared and randomly errors like the one below appeared:

Custom tool error: "Code generator 'ReportCodeGenerator' failed. Exception stack = System.IO.FileNotFoundException: File or assembly name CrystalDecisions.CrystalReports.Engine, or one of its dependencies, was not found.
File name: "CrystalDecisions.CrystalReports.Engine"
at CrystalDecisions.VSShell.CodeGen.ReportClassWriter..ctor(String filePath)
at CrystalDecisions.VSShell.CodeGen.ReportCodeGenerator.GenerateCode(String inputFileName, String inputFileContent)

I've searched the net and found a lot about wrong versions, deploying, etc. But I wasn't deploying anything, for crying out loud! First I thought it was about installing the Crystal Reports X runtime. I removed it, but that didn't solve anything. What was I to do?

Well, a temporary solution was to backup the .cs file somewhere, as it seemed not to change. Then I would just copy it back and add it to the project and it would work, but again, the time consumed by saving the report was huge! And there were caching problems. Sometimes I would see the report without the last modification in the application.

After a while I realised that actually I was deploying something. The project also had an installer, with the Crystal Reports .msm files. I remembered that I did install the application once, in order to test the installation process. Then, of course, I did remove it from the installed applications. That was it! All I had to do was to reinstall the application, thus repairing some Crystal Reports files or configuration that the uninstall process previously messed up.