issue with new create dbcontext class object in asp.net core 2.1 - entity-framework

Question

I m new in .net core 2.1
I m working with .net core 2.1 with code first approach
issue is when I create a new object dbcontext class then give error see below line
dbcontextstudent db=new dbcontextstudent(); //here give an red line
appsettings.json
},
"ConnectionStrings": {
"sqlserverconn": "Server=DEVISSHAHID; Database=studdbs; User id=xxxx;Password=xxxxx;"
},
Startup.cs
public void ConfigureServices(IServiceCollection services)
{
//connection string
services.AddDbContext<DbContext>(options => options.UseSqlServer(Configuration.GetConnectionString("sqlserverconn")));
student.cs
namespace WebApplication1.Models
{
public class student
{
[Key]
public int studid { get; set; }
public string studname { get; set; }
public string studsalary { get; set; }
public int studage { get; set; }
}
}
dbcontextstudent.cs
namespace WebApplication1.Models
{
public class dbcontextstudent : DbContext
{
public dbcontextstudent(DbContextOptions<dbcontextstudent> options) : base(options)
{
}
public DbSet<student> stud { get; set; }
}
}
HomeController.cs
I m not understood the above intellisense
I write the code as per intellisense but still give an error I know error is clear but not solved
which place doing I m wrong?

Answer 1

You will have to pass your DbContext type to the AddDbContext method in ConfigureServices method like this:
services.AddDbContext<dbcontextstudent>(options => options.UseSqlServer(Configuration.GetConnectionString("sqlserverconn")));
After that, you have registered the dbcontextstudent class in dependency injection.
You shouldn't create the instance of dbcontextstudent on your own like you did:
dbcontextstudent db=new dbcontextstudent();
Instead you can inject it though the constructor of your controller like this:
public HomeController : Controller
{
private readonly dbcontextstudent _db;
public HomeController(dbcontextstudent db)
{
_db = db;
}
... and then you can use the _db variable in your post action
}