Initialising Data seeding

Question

I am following Rick Anderson's lectures about ASP.Net Core Mvc. I am facing a problem in the fifth part about working with a database, concerning data seeding.
In program.cs I find a problem with the following statement:
//-----------------------
app.MapStaticAssets();
//-------------------------
When running the app I get the following error:

Error (active) CS1061 'WebApplication' does not contain a definition for 'MapStaticAssets' and no accessible extension method 'MapStaticAssets' accepting a first argument of type 'WebApplication' could be found (are you missing a using directive or an assembly reference?)
//-------------------------------
Rick has written: Test the app. Force the app to initialize, calling the code in the Program.cs file, so the seed method runs. To force initialization, close the command prompt window that Visual Studio opened, and restart by pressing Ctrl+F5.
//------------------------------
I tried everything, but not good enough because I still get the same error.
Does the problem relate to the seed method?
Appreciating any help

Answer 1

Hi @Abdou/Fawzy Aboyoussef

Error (active) CS1061 'WebApplication' does not contain a definition for 'MapStaticAssets' and no accessible extension method 'MapStaticAssets' accepting a first argument of type 'WebApplication' could be found (are you missing a using directive or an assembly reference?)

For this error, it does not relate the seed method. It might relate that you didn't add the.NET 9 SDK and Runtime in your computer.

So, you can check and try the following:

1. Use the latest version Visual Studio and install the .NET 9.0 Runtime (via Visual Studio Installer)
2. Check the project file, make sure you are using the .net9.0 TargetFramework, and upgrade the related package to 9.0 version.
3. Open the project root folder, delete the bin and obj folder, and then rebuild the application.

Besides, when using MapStaticAssets, refer to the following code:

Finally, if still not working, try to create a new .NET 9 MVC application and check whether it works or not.

In my application, the Program.cs file like this:

using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using Net9MVCSample.Data;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
var connectionString = builder.Configuration.GetConnectionString("DefaultConnection") ?? throw new InvalidOperationException("Connection string 'DefaultConnection' not found.");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
    .AddEntityFrameworkStores<ApplicationDbContext>();
builder.Services.AddControllersWithViews();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseMigrationsEndPoint();
}
else
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseRouting();

app.UseAuthorization();

app.MapStaticAssets();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}")
    .WithStaticAssets();

app.MapRazorPages()
   .WithStaticAssets();

app.Run();

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Dillion