I have been searching EVERYWHERE for this IObjectWithChangeTracker Interface that I think I need for a problem in my current project and I FINALLY discover (via this) that it isn't actually built into .Net
What I still can't figure out is how in the world do I use it!! I can't find the code anywhere, I have no idea what these T4 things are. Or where I find them. Someone help?
That site is specific for silverlight - entity framework already has self tracking entities.You can attach new objects you create as modified, deleted, etc, but altering a current object automatically tracks its state. So - what are you trying to do? : )
t4 files are code generation files. You can basically include a template (.tt file) in your project and when you run your project, the file is processed and generally create one or more code output files.
See:
http://msdn.microsoft.com/en-us/library/bb126445.aspx
Related
I create a lot of object classes when I do programming. There are many situations where same object definition will be reused across multiple projects. In windows, I simply build them into .dll file library and include them as the project reference. Therefore, when I need to add additional properties or methods, I just need to do it once and I don't need to worry about go through all projects and manually update the object class definition.
Now, I'm given a project to build an Android application which requires several object classes that's being used within other projects (and must be synced). Of course, I can manually create them within Android and update them every time whenever there's a change, but this is very dangerous because one day in the future, it is very likely to be out-of-synced.
Anyone have suggestions on how to share class library across C# and Android?
Thank you
The only way I know how to do this is to use Xamarin which would allow you to write your entire Android application in C#.
The problem is Android and .Net use completely different runtimes that are not compatible.
I don't have a clear enough view of what your application does, but if you are using the C# objects on a webAPI and looking to keep your objects synced with the client app, you can use Breeze.js - this keeps your client/server biz objects synced. The classes get pulled in dynamically via a meta service call.
I need to declare an attribute for coverage exclusion in my code, the issue is that i have a project group and i wish to create it somewhere where i can access it from all projects when i need it, right now i have it outside of the namespaces so it would be easier to use, and its declared in each project like:
public class CoverageExcludeAttribute : Attribute
{
}
is there any better way to achieve this goal in a way it could be access anywhere in my project group and declared only once, without having to add its namespace (e.g by using the global namespace) to each file i use the attribute in?
Thank you
While I actually agree with P.Brian.Mackey, I think the only way to do it is exactly as DjKraze said:
Create a new micro-project of type ClassLibrary, add a single .cs file with your Coverage(..) class and ensure that class is inside no namespaces block. Then build it and for each one of the other projects do a Add-Reference to that micro-project you just created.. That way it will surely work, and you will have a handy place to put any further 'common code' to be available everywhere.
However, each project will have to be updated with the reference. This is the minimum requirement - all in all, if you want to use anything instead of copying, it must be referred..
Sorry, almost no other options for such thing!
The other way is to .. ugh, copy. You can easily set up a simple pre-build script that will copy given .cs file to each one of your projects, but "adding" the file to the .csproj's build list is a bit harder, still possible with use of some Ruby or Python or friends...
Hm.. saying that, It may be possible to write a pre-build script to inject a reference to the micro-project automatically.. But I wont know if this is worth doing. Do you have more than 50-100 projects? Else, probably it's not worth..
This only applies to VS2010 and above
If you want some source code defined in each of your projects, but without a project reference, take a look at some of the functionality provided by NuGet, especially Source Code Transformations. These allow the addition of some source code to the project when you add the NuGet package to the project.
You can use Dependency Injection
http://en.wikipedia.org/wiki/Dependency_injection
The most popular are: Microsoft Unity, Ninject, NHibernate, StructureMap, Autofac.
Good luck!
Problem: Class B is a subclass of Class A. RIA service returns a list of object Bs. Class A and B are both necessarily defined on the server-side. They serialize fine, and I can use them in the primary client project.
I have two other libraries, organized as client libraries. One is for custom controls, and the other is for classes that are shared between custom controls and the actual client project.
I need Class A to be accessible from the Classes library clientside (so that the custom controls can get to it). How can I do this?
I've done this:
http://msdn.microsoft.com/en-us/library/ee707369%28v=vs.91%29.aspx
but the *.shared.cs convention doesn't give libraries other than the actual Client library access to Class A. The second method (Add as Link) does do what I want it to do, except that updating ClassA.cs in the server project doesn't cause the Client version to update, making it necessary to update both class files each time they're changed, which is unacceptable.
edit: Add as Link worked great after trying again several times.
In Visual Studio (2010, at least — dunno exactly whe the feature was added), you can add an existing item to a project as a 'link', meaning the source file is shared between projects. Only one version of the source file exists.
Right-click on your project.
Click on 'Add..Existing Item'.
Find the source file of choice and select it.
The 'Add' Button is a drop-down. Click the drop-down icon in the button.
Click on 'Add As Link'.
Easy!
Now any change to the share source file is reflected on both places. The drawback, of course, is that the developer gets no indication that changes to the shared source file might have wider ramifications than she might realize.
Another option would be to create a hard link so two file names reference the same file ('inode' in Unix terms). On the command line, just chant the magic incantation:
fsutil hardlink create <new-filename> <existing-filename>
something like:
fsutil hardlink create c:\foo\bar\some-project\bazbat.cs c:\foo\bar\another-project\bazbat.cs
The restriction is that both names have to be on the same volume.
This has the possibility, of course, confusing your source control system. I'm willing to bet that TFS hasn't consider the possibility that a filesystem isn't necessarily a tree structure and that the same file might exist in multiple directories.
Hard-linked files may be deleted in any order: the file ceases to exist when the last link to gets removed.
The 3rd option, of course, and likely the "best-practice" — hate that term! — is to factor out the shard classes into an independent assembly that gets deployed to both the client and server. If want to limit the number of assemblies floating around, post-build, you can use ilmerge to merge assemblies:
http://www.codeproject.com/Articles/9364/Merging-NET-assemblies-using-ILMerge
Merge two assemblies at runtime - C#
How to merge multiple assemblies into one?
Come to think of it, there's also no reason you can't embed the shared assemblies as embedded resources that get loaded on demand (or even at startup). This might even be cleaner than using ilmerge. Here's how to do that:
http://blogs.msdn.com/b/microsoft_press/archive/2010/02/03/jeffrey-richter-excerpt-2-from-clr-via-c-third-edition.aspx
I've been struggling to do this in a way that fulfills all of my requirements.
Here is what we have in our library:
Base classes for controllers and services
Business objects (stores, departments, etc)
Common Partial Views (Login, Error, etc)
Base class for HttpApplication
General common code (read an INI file, create a db conn, etc)
The one requirement that has been giving me trouble is as follows:
Lives in one place on a server. (i.e. copy local = false)
This breaks because:
The DLL containing the HttpApplication class must be in the same directory as the web apps dll to launch. I haven't found a way around that. I'm ok with duplicating this code in every app, but would rather not.
The shared views don't like to work if I use Assembly.LoadFrom() to load the dll from the shared location. (I've been using this method to precompile my views)
Any namespace shortcuts in web.config break at runtime with compilation errors because the web.config is parsed before the assembly is loaded.
My question to you folks is how do you handle your common code in a similar environment?
The GAC seems to be more trouble than its worth, and we want all of our apps to be using the same code, and not have multiple apps on multiple versions and have to maintain all of that. Are there design patters/best practices that can guide us in this regard?
Also, as a bonus, if you can solve any of the problems above, that would be great, too.
Thanks!
Edit: I guess a question that follows is whether or not we should even have a directory with the common dll(s) on the server, or if they should only be deployed as projects are deployed/updated?
Firstly, you will want to separate out what you're trying to achieve. Don't create 1 library that does everything or you will have a Big Ball of Mud. Don't be afraid to create several maintainable libraries to achieve what you're after. Is there a specific reason it needs to be stored in one location?
For example, several of the items you mention are MVC or web specific. If you have items that can be reused by MVC, create a class library that contains MVC base classes you inherit and reference them in your project. Use the single responsibility principle as much as possible.
Regarding the other items you mentioned, like database connectivity, if it's reusable, abstract it out in a data access class library and reference it. Other simple operations like reading an ini file or creating a file, create another library and abstract it to easy to use methods.
I prefer to copy the library dlls locally. You never know when you will need to make changes to the library, but you don't want all of your projects to stop compiling. When you're ready to implement a new version of the library, copy the dll in and recompile.
Not sure why all the hate towards the gac. It was designed to handle this specific problem. Install your common dlls to the gac and all apps can see them. Need to deploy a new one, just re-install it in one place.
Keeping properties of multiple Visual Studio projects manually in sync is annoying. So, how can you share properties between multiple projects?
Edit: I refer to properties like conditional compilation symbols, treatment of warnings and errors etc., i.e., things you can configure in Project->Properties tabs or by editing the project XML file.
Similar questions have been asked before, see: 1, 2 and 3. However, in my understanding, the answers have been C++-specific. I am looking for an answer for C# projects. Nevertheless, do not hesitate to answer for other kinds of projects (Visual Basic etc.) if you keep the separation clear, because someone else than me might be interested.
This blog post proposes a solution to the problem, but I would prefer something simpler.
Also, you can at least solve a part of the problem in the following way (note that although I tested it, I did not test it thoroughly):
Create an AssemblyInfo.cs file with the assembly attributes you intend to share. Link to this existing item in the individual projects. Use the original (local) AssemblyInfo.cs and put project-specific assembly attributes there. Unfortunately, overriding attributes does not seem to work, and managing the attributes via the GUI is now limited.
For that kind of things, I prefer to have a separate Class Library Project, with one (or more) static classes storing the (static) properties. Then add a reference to that project from every project that needs to have those properties in sync, and all those projects will have the same values and you have to change it in only one place.
For example, let's say that I have the same app in web and desktop form. Things like connection strings and such will have to be the same for both. So I will create three projects:
MyProject.Web (Web application)
MyProject.Desktop (Windows forms application)
MyProject.Common (Class library)
Then I add a new static class in Common called Properties with a static property called ConnectionString that returns the connection string.
I then add a reference to Common in Web and Desktop, and when I want to access the connection string from any of them I use Common.Properties.ConnectionString.
We make very heavy use of the .vsprops files to have shared macros defined between our native projects.
Someone asking exactly the same question as you came up with the idea of adding a "blank" visual C++ project to the solution so that could import the vsprops file and the properties would be generally visible to the rest of the solution. If it doesn't sound too gross a hack, I can find out how it worked out.