Error trying to scaffold a view in ASP.NET Core 6.0 MVC

Question

I'm trying to scaffold a new razor view using Visual Studio. I select a template, my model and my DbContext, then I get the error message shown below.

Things to note. My models, my DbContext and my website are all in different projects. From the message below I am using AddDbContext and I have a constructor that accepts a DbContextOptions parameter.

I read a comment on a blog post that the issue is because my context is in another project. The comment referenced something about the need to inject the Configuration into the DbContext to get the connection string and manually add it in the OnConfiguring override.

I can't find any examples if this is correct or how to set it up. Any help would be appreciated.

EDIT: Testing out the theory from the blog comment I mentioned above, I added this section into my DbContext. ConnectionString is a hardcoded string constant with my connection information. This does work and allow me to scaffold, so the question still remains. How can I inject this connection string into my DbContext to allow the scaffolding to work?

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    if (!optionsBuilder.IsConfigured)
    {
         optionsBuilder.UseSqlServer(ConnectionString);
    }
    else
    {
         base.OnConfiguring(optionsBuilder);
    }
}

EDIT: So after making this change, I checked in the code and had another developer pick it up. It appears this section above just needs to be there to allow scaffolding to work. He never changed the connection string to point to his environment. He no longer got the error above it just worked.

user_13701662 · Answer

I am not sure about what is the actual problem but it seems like we were having problems creating DbContext at design time. I manually added the code below and it's working now. It's just a temporary solution tho.

   public AppDbContext CreateDbContext(string[] args)
        {
            var optionsBuilder = new DbContextOptionsBuilder();
            optionsBuilder.UseSqlServer("Data Source=.;Initial Catalog=JwtTemplate;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False");
            return new AppDbContext(optionsBuilder.Options);
        }

Reference: https://stackoverflow.com/a/70559350

Error trying to scaffold a view in ASP.NET Core 6.0 MVC

1 Answers