After I installed Postal for MVC5 today, whenever I try to add a new MVC 5 View Page (Razor), I get the following error:
Error: this template attempted to load component assembly
'Microsoft.VisualStudio.Web.Mvc.5.0, Version=5.0.0.0, Culture=neutral,
...'
How can I fix this? I am not able to add new views to the project.
Well, first, you mean you're not able to use the view scaffold. You can add anything you want to your project manually. A view is merely a text file with a cshtml or vbhtml extension, depending on what language you're using in it (C# or VB, respectively). Once you do enough work with MVC, you'll find the scaffolds actually get in the way. They're slow and you've usually have to make mass changes to them anyways.
That said, attempt to create the view without a model. If that works, then Visual Studio is just being buggy as it's oft to be. Try closing Visual Studio completely and restarting it. That usually fixes these types of things.
Related
I'm leveraging a large existing codebase of business objects and their associated data access layer into an ASP.NET MVC web application. When scaffolding views for the business objects, the scaffolding engine fails with the following message in Visual Studio 2013:
Error
There was an error running the selected code generator:
'The method or operation is not implemented.'
In Visual Studio 2012, the error is:
Error
There was an error running the selected code generator:
'The Extender Provider failed to return an Extender for this object.'
Already tried:
Copying the default templates to a CodeTemplates folder: I got custom templates to work just fine on some POCOs I added directly to the project, but they fail on the real objects I want to use.
Wrapping the CodeTemplates in try/catch blocks with the catch set to write to trace: I tried this method but never got any trace results. I suspect the error is before the template itself starts processing.
Of note, the business objects are split into three partial classes each. The "Model class" select list in the "Add View" window shows three of each class name, but selecting any of the three for any of the business object classes gives the same error.
How can I find out what is causing the actual error and either correct it or find a workaround?
Check what version of EntityFramework are you using, if it is > 6.1.0
turn it to 6.1.0. or lower.
I dont know why it is so, but when i changed version of EntityFramework in my project scaffolding starts work correctly.
In my experiences, most error is either the code haven't compiled yet (It's kinda a weird issue, VS sometimes can't see the class that is not compiled yet), or perhaps different namespace used,
I hope that's really helps
I have a MVC5 project that is currently set on the "Release Configuration" and it works 100%. However, as soon as I switch the project configuration from Release to Debug, then everything goes wrong... even if I switch it back to Release mode, everything is still broken. Only way I can get the project working again is to restore from a backup.
Here are what is happening.
Firstly, when running the project, I get the following error:
BC30451: 'ViewData' is not declared. It may be inaccessible due to its
protection level.
If I open any view in the project with Visual Studio 2013, I can see that all sorts of things are marked as errors like ViewData, Html, Url, etc.
When referring to #Html or #ViewData in the view, it normally refers to the .Html and .ViewData properties of the view's base class (WebViewPage). However, if I start typing "#Html." in any of the views, I can see in the autocomplete that it is referring to the System.Web.Webpages.Html namespace instead of the WebViewPage.Html property. It is as-if the view isn't inheriting from the System.Web.Mvc.WebViewPage class.
Any guidance as to where I can start looking to get this fixed or why this is happening?
Edit:
So since nobody responded, I went through the long way. I created a brand new MVC5 project, added all the packages via Nuget and then simply copied all my files over from the old project to the new one and now it works.
Does anybody have any idea what the heck could be causing this? I don't want to go through all this trouble again in the future if the project again suddenly decides to stop working.
Ok, I think I've found part of the cause here. Thing is, since the original code is valid (it compiles correctly and intellisense picks it up) and the code used to work and then all of a sudden, one day after compiling, it just stops working.
Anyway, in the view, when specifying the ModelType, if you don't use the full name, this error can occur or occurs eventually.
For example, using:
#ModelType Models.SomeNamespace.SomeClass
will cause the error (even though the Root Namespace for the project is "MyProject") and it can be fixed by simply specifying the full namespace and class name.
#ModelType MyProject.Models.SomeNamespace.SomeClass
It's possible that a debug assembly is locked. Can close Visual Studio, search and delete for all bin folders in the solution directory. Then open and rebuild.
The other options is to go into the MVC project properties and compare the two build configurations. Are you targeting a different .NET framework between Release and Debug? 32 bit vs 64 bit? etc?
Looks like some MVC assemblies are corrupted.
Have you checked your referenced assemblies for some errors?
Try also cleaning all the .NET internal cache. More in this stackoverflow topic: Could not load file or assembly ... The parameter is incorrect
In my case imported ViewModel class name was incorrect, correcting it fixed the issue.
I have searched extensively and cannot find another person on the planet with this problem...
The symptoms are:In Visual Studio 2012, on a MVC 4.0 Project that was upgraded from VS2010 and is configured for dual version editing from VS2012 and VS2010. When I right-click on the Controllers Folder and select Add->Controller... from the context menu, I get an "Object reference not set to an instance of an object" error from Visual Studio.
The existing code in the project runs fine, and if I use the Add->New Item option instead, and pick the Controller from the dialog box, then I can add a blank controller. I just cannot add a typed controller using the method above.
If I however create a new MVC4 Project, then I can add typed controllers again using the same menu, so the problem does not exist in Visual Studio's installation, it has to exist in the Project File. I have also checked the references between my project and a new MVC Project and all the new project references are included in my project.Has anyone experienced something similar?How do I fix this?
The issue seems to have been caused by an incomplete install/registration of the MvcScaffolder package.
The following process resolved my issue for me.
Start Visual Studio and open the project. Open the Package Manager Console. (This was the "trick" or missing piece of information that led to the solution...)
Here I saw the following error caused by the PowerShell script used for registration:
New-Object : Could not load file or assembly 'System.Management.Automation, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.
At <ProjectPath...>\packages\MvcScaffolding.1.0.9\tools\registerWithMvcTooling.ps1:163 char:27
+ $newProvider = New-Object <<<< $powerShellScaffolderProviderType($mvcScaffoldingProvider)
+ CategoryInfo : NotSpecified: (:) [New-Object], FileNotFoundException
+ FullyQualifiedErrorId : System.IO.FileNotFoundException, Microsoft.PowerShell.Commands.NewObjectCommand
When I checked the registered scaffolders from the Package Manager Console I got:
PM> get-defaultscaffolder
DefaultName ScaffolderName
Action MvcScaffolding.Action
Controller MvcScaffolding.Controller
CustomScaffolder T4Scaffolding.CustomScaffolder
CustomTemplate T4Scaffolding.CustomTemplate
DbContext T4Scaffolding.EFDbContext
Mailer Mailer.Razor
Repository T4Scaffolding.EFRepository
UnitTest MvcScaffolding.ActionUnitTest
View MvcScaffolding.RazorView
Views MvcScaffolding.Views
So clearly the scaffolders are configured to use the MvcScaffolding package, but the package had a registration error.
A quick search for the error provided this link http://mvcscaffolding.codeplex.com/discussions/437692 which refers to https://visioautomation.codeplex.com/discussions/397034 that suggests installing PowerShell 3, which is actually part of the Windows Management Framework 3.0, available from http://www.microsoft.com/en-us/download/details.aspx?id=34595. I picked the Windows6.1-KB2506143-x64.msu file when prompted because I’m running Win 7-64-bit.
Restart the PC after installation, re-open Visual Studio and the project and look at the Package Manager Console. If the error is gone, then so is the controller problem.
I had this problem on VS2012 on Win8, We where working on a project that we started developing on VS2010 and i wasn't able to create new controllers with the CTRL+M, CTRL+C shortcut.
Opening any project and re-installing MvcScaffolder and its dependencies under Manage Nuget package have fixed this for me.
Didn't have to restart VS2012 at all.
Maybe your existing project have wrong ProjectTypeGuids element in .csproj file?
Right one for MVC4 is {E3E379DF-F4C6-4180-9B81-6769533ABE47}.
Try to compare what project type do you have in new project and in your existing project.
The preferred answer of installing the Windows Management Framework 3.0 did not work. The download "Windows6.1-KB2506143-x86.msu" did not work on my Windows 7 32 bit system. It failed with the error "The update is not applicable to your computer".
Reinstalling MVCscaffolding with Manage Nuget Packages did not work.
My ProjectType GUID was correct.
Microsoft Web Developer Tools was already installed.
Deleting and recreating the solution didn't work.
It was necessary to repair the Visual Studio 2012 installation from the install disk to fix this issue.
Installing "Microsoft Web Developer Tools" fixed this for me. Related:
How do I open a csproj with ProjectTypeGuids 349c5851-65df-11da-9384-00065b846f21?
{E3E379DF-F4C6-4180-9B81-6769533ABE47} - MVC4 Project
{fae04ec0-301f-11d3-bf4b-00c04f79efbc} - CSharp Project
{349c5851-65df-11da-9384-00065b846f21} - Web Application Project (this is what you need web dev tools for)
The update Windows6.1-KB2506143-x64.msu worked for me. The problem started after a full SpyWare software scan. I think that it removes more things than the usual. So, back to normal life.
I had the same problem, im using database first, and it was because i have changed the .edmx contex.tt to generate the contex.cs with the connection name set to a custom method,
: base(sqlHelper.getMainConnectionString())
every time, before i change/update the .edmx, i need to change the connection name to it's creation defaults:
: base("name=YourWebconfigConnectionstringName")
rebuild the project and it works again
Answer:
Check your connectionstring string and provider parameters at the webconfig, then delete and recreate the .edmx this will force the generator to rebuild all the database objects, metadata included OR delete all tables in the designer, change the contex.cs to the default creation name, rebuild the project, add the tables, rebuild the project, it shoul work again.
This problem manifested on a target MVC5 project using VS2017.
Like the original op, a new project was attempted to perform an Add Controller with EF scaffolding against ApplicationUser. The error did initially manifest until a single user was registered forcing the database to be created. After that, add scaffolding worked without incident. I think this makes sense because the entity didn't really yet exist before the first registration, although I will stand corrected if someone more knowledgeable than myself has a more accurate explanation. But because Add Controller worked with a new project, just as the original op determined, it didn't seem to be a VS2017 installation problem. This pointed to something wrong with the taret project.
At this point in the target project an Undo All in Team Explorer was executed to get the project back to a previously working point. While this might be accomplished by getting a specific version, for this target project all that was required was an Undo All. A word of caution: in the case of this specific project, before undoing, the Package Manager was used to rollback the database to the starting point that would match with the Undo All. If one performs a get specific version, be sure to check if the database needs to get rolled back to the proper configuration. After resetting all the project changes, the object reference not set to an instance of an object error was no longer present during the Add Controller operation, fixing the error within the target project.
I post this response somewhat reluctantly because I am unable to duplicate the error, and I am unsure of what actually caused the problem in the first place, but this is a particularly nasty error if one is in the middle of a project and Add Controller starts failing. I figured if someone has this problem and rolling back the current change set might fix it for them, like me they will be thankful. If I later determine the pattern of activity that caused the problem to crop up in the first place, I'll surely add more to this post.
I'm running VS 2019 Enterprise, ASP.NET Core 3.1.3.
I was trying to add MVC controller with views using Entity Framework (EF) after scaffolding in database first approach.
I run on this issue because one of the tables in my ER model was missing primary key.
That table was connected to table for which I tried to generate MVC controller through another table that has primary key so I didn't noticed initially that error.
I’ve created a new C# asp.net mvc 4.0 (beta) Internet Application and I’m having a somewhat odd behavior in the Add View dialog in Visual Studio 2010 (sp1).
When I decide to create a strongly-typed View, inside the Add View dialog, the Model class dropdown does not show my ViewModel class.
For the record, yes I did compile the application before triggering the Add View dialog.
I believe I have pinpointed the issue but do not know how to fix it.
Below are the repro-steps if anyone cares to reproduce the behavior:
In Visual Studio 2010 (sp1), create a new C# asp.net MVC 4.0
(beta) Internet Application.
Inside the Models folder, create a new simple class called
“GazouViewModel.cs”
Build the application, open the HomeController, right-click the
Index() ActionResult and select Add View…
In the Add View dialog, check the “strongly-typed view” checkbox and
in the Model class: dropdown, you’ll notice your “GazouViewModel”
In Solution Explorer, right-click your project and select “Manage
NuGet Packages”
Search, find and install the “Bootstrapper.Autofac” package.
Rebuild the application and verify if your “GazouViewModel” still
displays inside the Add View dropdown’s dialog.
The “GazouViewModel” should still be displaying in the dropdown.
In Solution Explorer, right-click your project and select “Manage
NuGet Packages”
Search, find and install the “Autofac ASP.NET MVC4 (Beta)
Integration” package.
Rebuild the application and verify if your “GazouViewModel” still
displays inside the Add View dropdown’s dialog.
The “GazouViewModel” should still be displaying in the dropdown.
In Solution Explorer, right-click your project and ADD a new class
(Class1.cs) anywhere it doesn’t matter.
Make that Class1 implement IAutofacRegistration and implement the
interface.
Rebuild the application and verify if your “GazouViewModel” still
displays inside the Add View dropdown’s dialog.
The “GazouViewModel” is no longer showing inside the Model class
dropdown.
It appears that as soon as I create a class that implements the IAutofacRegistration interface and build the application, I’m no longer capable of viewing my ViewModels in that dropdown.
Can anyone confirm if they are getting the same results as me?
And more importantly, how can one fix this?
IMPORTANT: I have tried the exact same steps with an mvc 3.0 application and the exact same behavior occurs…so this is not relevant to the BETA version.
Sincerely
Vince
If you get error message: "Running transformation: The input file appears to be using a schema version not supported by this template. This may lead to compile errors. Please use 'Add New Generated Item' to add an updated template".
You are used EF 5.x. You have to add metadata for EF 5.x to your T4 template. In file header call DefineMetadata()
<## template language="C#" debug="false" hostspecific="true"#>
<## import namespace="System.Text.RegularExpressions" #>
<## include file="EF.Utility.CS.ttinclude"#><## output extension=".cs"#><#
DefineMetadata();
at the bottom of your template create method
private void DefineMetadata()
{
TemplateMetadata[MetadataConstants.TT_TEMPLATE_NAME] = "CSharpDbContext.Types";
TemplateMetadata[MetadataConstants.TT_TEMPLATE_VERSION] = "5.0";
TemplateMetadata[MetadataConstants.TT_MINIMUM_ENTITY_FRAMEWORK_VERSION] = "5.0";
}
I solved this issue by beeing mad in like 2 hours and then deleting the Assembly.cs from the Properties-folder in the solution. After I made a rebuild of the solution, the "Add-view" model-dropdown suddently could find all my ViewModels, strange enough.
I guess the assembly version defined in Assembly.cs somehow got mixed up with the actual version used in the project. Anyhow, it works now for my case.
What worked for me was to simply build the solution after creating my model. Then I was able to find my model in the dropdownlist.
I've noticed this issue as well (using MVC 4 Beta on Visual Studio 2010). Re-starting Visual Studio solved the problem for me.
Just another solution to add to the pile as none of the other ones worked for me. This is another example of Visual Studio being terrible at handling long file paths and namespaces.
In my case the namespace was too long to display in the "Model class" dropdown. Shortening the namespace (a ridiculous pain in of itself) made the drop down work again!
UPDATE: As of this writing, I can no longer reproduce the error. Perhaps the NuGet packages I use have been updated to a newer version and incidentally fixed the error.
I will mark this post as closed.
Thanks for everyone’s input on this!
Vince
Just Clean and build your solution. It worked for me.
Using VS 2010 and MVC 3.0, at one point the Add View Model class dropdown was not showing any classes for me. Ivan's suggestion of restarting VS appeared to work for me.
I tried deleting AssemblyInfo.cs, did a Clean, and a Rebuild, but those didn't resolve the issue. When I restarted VS, the model classes were back in the dropdown.
I realize this is a bit out of date. I had a similar situation where my classes wouldn't load into the View Template wizard. I'm using VS 2012 with MVC3. Everyone else in the team was OK, just luckily old me had issues. After much research and trying lots of things the only thing that has consistently fixed it is running VS in safemode (from the command prompt: "C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\devenv.exe" /safemode). One of my extensions must be causing the issue and by running in Safe Mode those aren't loaded.
In WinForm and WebForm Application, Visual studio groups the 'View' File and 'Contorller' File, together. I found very easy to manage file in that way.
Now in ASP.Net Mvc , i'm finding difficult to manage views, separately in completely different folder.
Is there any way to group View and Controller files in VS Solution Explorer, like we used to do in WinForm and WebForm Application ?
I think they did that on purpose - views should be independent from controllers. Think of it like this: you should be able to put controllers into a totally different assembly and still have your application work. Your controllers should also be able to work with totally different set of views.
The framework is also setup to go to the views folder to fetch appropriate files. You would have to change that behavior yourself if you decide to move the views. Might not be worth the hassle.
And finally, if you really want to do it, you should probably look at your project file. There is a DependsUpon element that you can use to make a file go underneath another:
<Compile Include="Form1.Designer.cs">
<DependentUpon>Form1.cs</DependentUpon>
</Compile>
you can use VSCommands to group/ungroup files directly from Visual Studio