I'm pretty sure I know the answer but I'm wondering if there's a way to define a global "using" directive in my C# projects so that I don't have to repeat the directive on top of every code file.
My interest is really rooted with the introduction of extension methods in the .NET Framework. The only way to use an extension method is to define a using directive for the namespace containing the extension methods. Without the using directive, I lose Intellisense capabilities for the extension methods which means I won't always see what methods are available.
As a framework developer, making sure that the types and methods that are provided in the framework are clear and available to consuming developers is key to me. While documentation and training serve their purpose, I've found that most devs will hit the period and scroll through the Intellisense list to see what methods and properties are available. Even if they go to the Object Browser or view the reference documentation, they won't know about an extension method unless they know about it. This is where Intellisense comes in.
And, while I can add the using directive to the template VS uses, the "Remove and Sort" option in VS will remove the directive referencing the extension methods if one isn't being used.
So, all that being said, is there any way to define a global "using" directive in VS 2010? If not, any chance it's being considered by MS for the future?
You can place your extension methods in the global namespace, by making sure the containing classes are not declared within a namespace. This will make them globally available.
As for default namespaces - apart from changing the VS templates, this is not possible.
Of course, it is always possible the MS will consider it. Unlikely, but possible.
Instead of looking for a technical solution, perhaps you should look at educating your fellow developers and provide a convention regarding extension methods (for instance, a known location/namespace schema)?
The global using directive is a new language feature in C# 10. When running on .NET 6 there are also implicit global using directives available in certain namespaces.
In VS 2010 there is no option to do it but in VS 2022 with C# 10.0 you can use Global Usings.
global using <TheNamespace>;
To answer your actual problem, if you put your static class with extensions in no namespace, it will be available everywhere. Use with care!
If it's really important to you, you can have your company buy ReSharper and install it on all development machines, having this will give you Intellisense for those methods, with option to "auto add" the using directive.
From what I heard (didn't use it myself) the ReSharper scan all possible assemblies and I assume you can configure it to add "using" directive automatically when creating new class, though I'm not 100% sure in this.
You can create .net file templates for classes that contain your using directives.
See Creating Project and Item Templates (https://msdn.microsoft.com/en-us/library/ms247121.aspx).
You can save the template as part of the project you have your extensions in; however, this is best done in a different project.
Global using directives are introduced within C# 10.
It can be used through the same way as local using directives, except that you place a global keyword in front of it, in order to instruct the compiler to give access to the following directive accross the entire project:
global using System;
The recommended standard is to put all of your global using directives in a Usings.cs file to separate them from the rest of the project.
Related
How can I have a using directive that has a scope of the whole program instead of just the file it is in. For every module that I use I would only want to set this once. If there is no way to do this what is the workaround to get this to work.
I thought about putting them all into a header file but C sharp does not have a file include.
This is not possible. Fortunately.
Just wondering why you want to do this. This would be a bad programming habit anyway - put concerns and dependencies only when you really need them. If you add the same using directives everywhere, you also need the referenced assemblies everywhere, something you really don't want to do. Your project should rely on assemblies it needs, no more, no less.
Your argument about wasting time is a bit strange; if you loose so much time, you might have another problem in your architecture.
Note: Resharper is a tool that you may find useful.
Sorry, but what you are trying to achieve is not possible and I don't think that there are any workarounds. This is supported for example in WebForms or Razor views where you could declare common namespaces in the <namespaces> section of your web.config but unfortunately such artifact doesn't exist for standard C# files.
Having the using directives in each single .cs file allows you to take that file out of an existing project and drop it into another project, provided it has the same references.
Also, adding using directives is basically automatic at this point. My tool of choice, ReSharper. Place the cursor on whatever class isn't recognized, press Alt+Enter, and the using directive gets added automatically. If there are multiple choices, you get to pick the right one.
This is such a dumb question, but I can't figure out the lingo to ask Google.
In Java if I wanted to import all subclasses I would use something like
java.util.*
And all of util would be imported.
Firstly, what is the proper lingo for what I'm doing in C# so I can start using Google more effectively. Am I importing namespaces? Libraries? Subclasses? (Can you tell I'm new at this?)
Secondly, since I'm here, how is this accomplished in C#?
PS- I did click on every related question stackOverflow threw at me to see if the answer would pop up. No luck. I'm simply without words to describe what I'm looking for. The example should do just fine but... Anyone who can take a moment to either explain the lingo to me or perhaps simply point me at something that can (in a nutshell, I have a couple books for the long haul) that would be great.
Firstly, let's differentiate between assembly references and namespaces.
Assemblies are what you add references to in your c# project, they are the libraries that contain the actual classes you need, usually found as DLL files. The .net framework contains many such assemblies, and Visual Studio will try to reference the most commonly used ones in your project (e.g. for a WinForms project it will automatically add a reference to System.Drawing.dll).
Namespaces are logical partitions of the classes in an assembly.
Once you reference an assembly in the project, all classes in all namespaces are available for use, if you provide their full name.
This is where the using directive comes in.
It is simply syntactic sugar for not having to write very long names all the time.
For example, assuming your project references the System.Drawing.dll assembly, you would have to qualify a class from this assembly using it's full name, for example
System.Drawing.Imaging.BitmapData
Because this is tiresome and bloats the code, if you start your .cs file with
using System.Drawing.Imaging;
you could then instantiate a class using just the name BitmapData.
This will be true only for the .cs file in which you added the using directive, not for the whole project.
Also, it's important to note that using one namespace does not bring in all nested namespaces, you have to using each one individually.
You must brush up on your your Google-fu
http://www.harding.edu/fmccown/java_csharp_comparison.html#namespaces
It can be called importing / referencing/ using namespace.
Such a language feature is not available in c#.
A little explanation: Namesspaces can be spread across multiple libraries. so when you use a namespace it may refer to it from multiple referenced assemblies.
It's called namespace and it's imported by a keyword using. For example:
using System;
This statement enables you to reference all the classes that exist in that namespace. They, however don't enable you to reference any class in the subnamespace of declared namespace. You have to declare each namespace separately. For example:
using System;
using System.Text;
Of course, you need to have a proper references added to the project where you're specifying the using directive.
Within .Net, you first would need to ensure that there is a referenced assembly containing the namespace you would like to import. Once that reference exists, you can use the 'using' directive to bring that namespace into the class so as to not have to fully qualify all object names. You can find more information on this directive on MSDN.
If I misunderstood, let me know and I'll do my best to get you pointed in the right direction.
I'm a C#/.net/Visual Studio noob. I inherited a half-completed C# application for a mobile phone. In the course of debugging, I came across several half-finished classes that don't seem to be used anywhere else in the code. Is there a way to get determine if a class definition is instantiated anywhere?
The quickest way (in Visual Studio) is to right-click the type name and select Find all references from the context menu. This will show you all places where that type is referenced in the current solution.
You should get Resharper - it will show "dead" code in grey and make refactoring a lot easier! You may also prefer CodeRush.
Without ReSharper or a similar tool, you can always do a file search for "new ClassName(" in the entire solution.
I usually start with Shift-F12 (or right-click on class name and select "Find All References")
Unless you know the code, and the modules that may use it., CodeRush or Resharper are your better choices.
None of the other answers mentioned the modifiers which can be applied to classes/functions. You certainly want to take scope into consideration before deleting code. You may have other assemblies which use classes/functions.
Remove them from the project and let your unit tests (ahem, you have those right?) and your QA team (you have that right?) identify the problems.
Jokes aside, if it's SO obvious that it's not complete, why not simply remove the code and recompile?
The next steps I would take would be to use a tool like "Find All References" or Resharper (does it even have a feature to do that?)
You can list all the classes (searching for class [a-zA-Z0-9_]+), and then search for new <classname>. The ones not found at the second search are not used. Of course, a simple script in your favourite script language would help.
You'll need however to filter out the classes that are used as base classes of used classes.
Note that this way you'll not find the classes which are used only from unused classes, so several iterations might be needed. Moreover, if some two classes are using each other (but not used from outside), removing them might need additional effort.
Edit:
A better approach would be building dependency tree: for each of the classes you define which class is used by that class, and which class is a base class for that class. This way you find which classes are required for every single class. Then, you can define which classes are required (directly or indirectly) from the class containing Main. All other classes are "unreachable" and therefore not used.
This approach will however remove the classes instantiated by reflection. Well, there is no way to find out at compile time, which classes are going to be instantiated by reflection anyway.
Maybe using the ready tools (like others proposed) is a simpler alternative.
I've got a bit of a conundrum on my hands.
I'm currently compiling a load of 'code snippets' into reusable libraries that I obviously intend to use in multiple applications.
I'm having trouble deciding on an appropriate namespace and assembly name.
Basically, I've currently got JasonSummers.Validation as an example for my validation library, since I have no 'company' and no specific project which the code applies to.
However, later on, when I come to use said namespace in a client's project, I don't think it's really appropriate to have my name referenced in code which they will probably own the IPR for.
I would just use 'Validation' as the namespace (after all, StructureMap is StructureMap, not JeremyMiller.StructureMap) but this may cause confusion for future developers as 'Validation' is used in the 'System' set of namespaces provided by .net
All comments greatly appreciated.
You can always use name from biology e.g Tribulus. or any other for your root namespace. So your code goes into e.g Tribulus.Validation or Tribulus.Utilities etc. Toplevel namespace need not to be a functional name. It can be just a signature of a company or just a unique interesting name as i mention.
In my personal experience, I maintain a code base for that useful functions at source level, i.e., I copy every function I need in every project, under my client brand and assembly name.
I didn't found be useful to keep that functions at assembly level, exactly because that: it'll contain some names which can generate confusion and for an extra reason: a client paid for some functionality, but not for another (include in a general assembly). So, I just pack what he/she bought.
An option could be to use a neutral name, like Reusable and to merge your utility assembly by using ilmerge framework command.
Take a look at Microsoft's Namespace Naming Guidelines
I got it as an answer from Konamiman to my question which is related to yours.
I have a class that uses filesystem entities to manipulate data. We have several methods specifically designed to (attempt to) cope with some of the issues we face with this approach (file locking, non-existent files, etc.). Ideally I'd like to be able to issue a warning if another developer attempts access the filesystem directly via System.IO rather than using the helper methods.
Is this possible? The behaviour I'm looking for is to effectively mark methods such as File.ReadAllText() as if they were obsolete, but only within this project (NOT solution-wide).
I've done some digging around, and it looks like my only option is "tell them to make sure they use your methods". I'm hoping someone can give me a different, and more helpful answer. :)
--EDIT--
The suggestions of a custom StyleCop or FxCop rule are good, but unfortunately impractical in this scenario (not every developer in the department uses these excellent tools), and the legitimate methods that do the file access do use System.IO. Adding "ignore" attributes to the legit methods is a dangerous idea, too. If someone sees how I've "broken" my own rule, they'll likely copy the attribute to their own method.
Use a static analysis tool (such as StyleCop or FxCop) with a rule that captures "Do not use System.IO directly." Then integrate it as part of your automated build process and throw up if someone does try to use System.IO directly. No one likes to break the build.
You can write custom analysis rule for FxCop/Visual Studio Code Analysis and run these as part of your automated build.
Hmm. Not tried this myself, but how about forcing people to use your custom file handling classes, by using a namespace alias that "hides" the genuine System.IO. If I remember rightly these are applied at a project level.
Not sure if either of these suggestions are valid as I've never done them, but some food for thought:
Isn't this what "Enterprise Templates" are designed for? Don't they allow you to craft a policy file that restricts the allowed project references?
Alternatively, while not foolproof, could you add a pre-build event to the project that throws a warning if System.IO is referenced?
Can you add some custom functionality to a source-control commit hook? It won't find existing violations (if there are any) unless those files are changed but should detect new uses?
Any good?