I have a puzzling issue with Visual Studio 2017 and C#. The editor thinks one of my base classes does not exist. It keeps giving me a red-squiggly line underneath it with the message that the class cannot be found. I inherit from this class in two places and get the same red squiggly line.
But what is odd is that:
My application runs perfectly.
I can debug it and step into the derived and base class code with no problems.
I can still right-click on the class name and go to definition and it goes to the right place.
Both the base class and the derived class are in exactly the same namespace in the same assembly. Their source files are in exactly the same folder and both are public classes.
I do not have this problem with any other class in my solution (which is large)
Here is one example of the inhertance that's giving me the red squiggly line
using System.Collections.Generic;
using Trainer.Core.Interfaces;
using Trainer.Core.ViewModels;
using Trainer.Model;
using Trainer.Sdk;
namespace Trainer.Capture.ViewModels
{
public class CalibrationJob : JobVm // <-- RED SQUIGGLY LINE UNDER "JobVm" HERE
{
... etc ...
When I put the mouse cursor over the red-underlined base-class name "JobVm", I get the following error message from Intellisense
"The type or namespace 'JobVm' could not be found (are you missing a
using directive or an assembly reference?)"
Here are the first few lines of JobVm's source file
using System.Threading;
using System.Windows.Input;
using Trainer.Core.Interfaces;
using Trainer.Core.ViewModels;
namespace Trainer.Capture.ViewModels
{
public class JobVm
{
...
So I tried changing the inheritance explicitly specify the full base class name
namespace Trainer.Capture.ViewModels
{
public class CalibrationJob : Trainer.Capture.ViewModels.JobVm
{
... and then the error message became slightly different:
"The type or namespace JobVm does not exist in namespace Trainer.Capture.ViewModels"
But of course it does exist. It's right there in the same assembly and folder.
I've tried to find a way to delete the Visual Studio intellisense cache but I don't have any .SDF files and I don't see anything else. This is a completely C# solution.
I guess I can keep on going as everything works fine but this is bugging me. I'm thinking there must be some other issue.
Any idea what's going on here? Am I missing something obvious?
Even though they use the same namespace, if your objects are in different projects, then you want to make sure any Nuget packages or included assemblies used in each project are running the same version. I have found that if one project is running a different version then you may get the squiggle lines. I have experienced that before.
Related
I have a nested namepace DO as a part of a big project.
namespace IDAL
{
namespace DO
{
public struct MyStruct
{
// Code
}
}
}
I need to change the name of the IDAL namespace to DalApi and the nested namespace IDAL.DO toDO.
The first part was easy enough using the Visual Studio Rename option.
I ran into more difficulty with the second part. I can't use the Rename option to extract the namespace and make it a non nested namespace.
I tried just removing the outer namespace like this,
namespace DO
{
public struct MyStruct
{
// Code
}
}
but the I needed to start fixing up all of the times that the namespace was referenced (i.e. IDAL.DO.WeightCategory - where WeightCategory is an enum needs to be changed to DO.WeightCategory just to give one example). While that seemed that it would work, it seemed that it was a lot of difficult work which probably had an easier solution.
I tried to use the Ctrl+H search and replace feature to try and replace all instances where this happened but it didn't seem to solve the problem (it was set to replace for entire solution).
Is there a Visual Studio 2019 tool where I can easily change (refactor) a nested namespace to a non nested namespace?
From Visual Studio, while having the cursor on MyStruct, do a CTRL+. on it:
And then just click on "Move to namespace..." and write whichever namespace you want, and VS will take care of the rest:
Do you also need the effective namespace IDAL.DO to change? If not you could simply swap to the fully qualified namespace like so:
namespace IDAL.DO
{
public struct MyStruct
{
// Code
}
}
If you do want to change the full namespace to become simply DO then refactoring tools are indeed what you'll need to use. The following links should get you started in that regard:
https://dev.to/gopkumr/adjust-namespaces-automatically-visual-studio-2019-1f0b
https://learn.microsoft.com/en-us/visualstudio/ide/refactoring-in-visual-studio?view=vs-2022
https://learn.microsoft.com/en-us/visualstudio/ide/reference/extract-method?view=vs-2022
https://learn.microsoft.com/en-us/visualstudio/ide/reference/move-type-to-matching-file?view=vs-2022
I have been looking around for a while now to see how can I enforce my C# projects to have full namespace path.
For example actual if namespace for class X is Foo.Bar.Car.Dealer when doing Ctrl+. in visual studio it sometimes puts statement like using Car.Dealer; this specially becomes a problem with multiple projects solution. I have been looking around for StyleCop rule or something that might help me get this done.
Any help or ideas?
EDIT
The above statement holds true only if the using class falls under same namespace prefix. Here is complete code example:
File: X.cs
namespace Foo.Bar.Car.Dealer {
class X {}
}
File: UsingClass.cs
namespace Foo.Bar.Another.ClassPath {
using Car.Dealer;
class UsingClass {
private X _x;
}
}
The VS picked using Car.Dealer but I want to enforce using Foo.Bar.Car.Dealer
I do not know about versions prior to 2012, but from then on the icon that pops up for action upon coming across an unknown type offers both adding the namespace via using directive or to simply prefix the type being referenced by the full namespace.
If you do not want to add the namespace via using directive (which would look like using Foo.Bar.Car.Dealer;),
then in your example you simply need to reference your type X as Foo.Bar.Car.Dealer.X.
Example:
//assuming your X type is instantiable
Foo.Bar.Car.Dealer.X myX = new Foo.Bar.Car.Dealer.X();
I got a strange error when tried to build my project ExpertSystem in solution ExpertSystem:
Error 1 The type name 'App' does not
exist in the type
'ExpertSystem.ExpertSystem' D:\Users\Kirill\Documents\Visual
Studio
2010\Projects\ExpertSystem\ExpertSystem\obj\x86\Debug\App.g.cs 60 26 ExpertSystem
I didn't even knew that VS creates this file while building. So, I started search the problem in my last edits in code and found that problem is in my last class:
namespace ExpertSystem
{
public class ExpertSystem
{
//...
}
}
When name of class is changed to something different from ExpertSystem, project compiles without errors.
Can anyone explain, can I actually have classes in C# with the same name as namespace/project/solution? Or is this a some kind of VS/WPF bug?
Thanks.
VS generates partial class for each XAML file (not during build, but during design), in order (for instance) to declare and fill the named components as class fields.
If you want to easily read the content of the designer generated App.g.css file (associated with the App.xaml and App.xaml.cs file), go to the App.xaml.cs file and perform a "Go to Definition" on the InitializeComponent() function call in the class constructor. I don't know what lurks in your, but I would expect that the designer generated something like this (maybe not this, but the issue will be the same):
var foo = (SystemExpert.App)(Application.Current)
Which should be understood as:
var foo = (global::SystemExpert.App)(Application.Current)
Now, if you create a SystemExpert class in your SystemExpert assembly namespace, and as the App class is declared in the SystemExpert namespace too, the compiler will understand that:
var foo = (global::SystemExpert.SystemExpert.App)(Application.Current)
^^^^^^^^^^^^^^^^
the current namespace
Naming a class exactly the same way as a namespace is bad practice: it can confuse the compiler.
Can anyone explain, can I actually have classes in C# with the same name as namespace/project/solution?
Yes, you can. It's part of the C# language.
Therefore the compiler can't figure out whether the code meant to look for the ExpertSystem.ExpertSystem namespace or the ExpertSystem class in the ExpertSystem namespace. (Well it can, but it got it wrong.)
To complement BoltClock's answer with a solution that will work while keeping the namespace and class names as they are:
The error is reported in a file named App.g.cs, which is generated by the compiler. Thus, fixing the issue in that file will not help, as the file will be overwritten with the error upon the next compilation (or rewritten once you have copied the code to another machine).
However, you can change the App.xaml file, from which App.g.cs is generated. The root element of the file will start with something like
<Application x:Class="ExpertSystem.App"
In there, the namespace ExpertSystem is supposed to be found, but with the class having the same name, the compiler assumes that App is a member or a nested type in your class ExpertSystem.ExpertSystem.
By pondering about this, you will realize that the compiler first tries to evaluate the value of the x:Class attribute relatively to the ExpertSystem namespace for some reason. This behaviour is responsible for your problem, but as we now know the specifics of the behaviour, we can write the code accordingly - with an identifier that is qualified relatively to the namespace ExpertSystem:
<Application x:Class="App"
After this change, it should compile fine, even if both the namespace and the class are named ExpertSystem.
I've got a project with several namespaces and many classes contained within one of them ->
Some.Namepsace. (namespace)
ExistingClass (class)
ExistingClass2 (class)
Constants (class)
.Enum (enum)
Within this project I created a class, but with an incorrect namespace like so
namespace Some.Namespace.Some.Namespace
{
public class NewClass {}
}
Now Some.Namespace.ExistingClass cannot resolve a reference to Some.Namespace.Constants.Enum - it appears to be looking for Some.Namespace.Some.Namespace.Constants.Enum.
Any idea why? NewClass does not reference anything, and is not referenced by anything so I don't see how it's namespace could affect any other components. I fixed the namespace issue on NewClass, and that fixes it.
A class inside Some.Namespace.Some.Namespace will try to resolve Some.Namespace.Constants.Enum
as: Some.Namespace.Some.Namespace.Constants.Enum, not Some.Namespace.Constants.Enum.
It would work if you tried to refer to the Enum as: global::Some.Namespace.Constants.Enum.
This must have something to do with the way C# in visual studio/csc attempts to resolve references. It would appear it goes something like this:
Look relative to the namespace of the calling object
If such a namespace is not found, attempt to look up the reference as if it's absolute
In my case, before I added Some.Namespace.Some.Namespace.NewClass, when VS tried to resolve the reference from Some.Namespace.ExistingClass to Some.Namespace.Constants.Enum, it first attempted a relative namespace lookup (starting from ExistingClasse's Some.Namespace), found no such namespace. It then attempted an absolute lookup and found it.
After I added Some.Namespace.Some.Namespace.NewClass, it found the namespace, noticed the object was not there, and decided to discontinue searching.
I'm having a problem with conflicting namespaces and code that gets autogenerated by the forms designer in Visual Studio 2008. I have search many forums and different documentation, but have not been able to find any solution to this problem.
I have one assembly called Foo.dll with the following namespace/code:
namespace Foobar.System
{
public class MySystemClass() { }
}
Then, I have another assembly which contains som commonly used forms:
namespace Foobar.MyCommonForms
{
public class MyForm : System.Windows.Forms.Form
{
public void SomeMethod()
{
var systemclass = new Foobar.System.MySystemClass();
}
}
}
Here, the compilers display the following error: Type or namespace 'Windows' is not part of namespace 'Foobar.System'. Obviously, the compiler tries to look for the class System.Windows.Forms.Form in namespace Foobar.System.Windows.Forms!
I have been able to solve this by using the alias 'x' instead of 'global' when referencing to the assembly Foo.dll, and declaring 'extern alias x' in my code files, and put 'x::' in front of every reference to types and classes in the namespace Foobar.System. The code compiles.
But it seems that the forms designer don't recognise this, and gives me an error when trying to display the form. This, again, can be solved by manually putting 'global::' in front of every reference to classes in System.Windows.Forms (e.g. global::System.Windows.Forms.Button), but every time chances are made to the form, the code is automaticaly re-generated, and the 'global::' part is removed.
So, the question is: Is there a way to make the forms designer aware of the alias 'x' that is used to reference my assembly Foo.dll, or is there another, better solution to this? Renaming the namespace Foobar.System to something else is just too much work.
There's no way around this, from what I can tell.
The popular refactoring tools such as Resharper or Refactor! both include the ability to globally rename a namespace. I'd seriously consider using those.