ASP.NET Core 6 how to access Configuration during setup-CodePudding

In earlier versions, we had Startup.cs class and we get configuration object as follows in the startup file.

public class Startup
{
    private readonly IHostEnvironment environment;
    private readonly IConfiguration config;

    public Startup(IConfiguration configuration, IHostEnvironment environment)
    {
        this.config = configuration;
        this.environment = environment;
    }

    public void ConfigureServices(IServiceCollection services)
    { ... }

    
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env) 
    { ... }

}

Now in .NET 6 (With Visual Studio 2022), we don't see the Startup.cs class.Its altogether removed. So how do we get these objects like Configuration(IConfiguration) and Hosting Environment(IHostEnvironment)

How do we get these objects, to say read the configuration from appsettngs? Currently the Program.cs file looks like this.

using Festify.Database;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorPages();

builder.Services.AddDbContext<FestifyContext>();


////////////////////////////////////////////////
// The following is Giving me error as Configuration 
// object is not avaible, I dont know how to inject this here.
////////////////////////////////////////////////


builder.Services.AddDbContext<FestifyContext>(opt =>
    opt.UseSqlServer(
        Configuration.GetConnectionString("Festify")));


var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/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.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapRazorPages();

app.Run();

I want to read the configuration from appsettings file.

CodePudding user response：

WebApplicationBuilder returned by WebApplication.CreateBuilder(args) exposes Configuration and Environment properties:

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
...
ConfigurationManager configuration = builder.Configuration;
IWebHostEnvironment environment = builder.Environment;

WebApplication returned by WebApplicationBuilder.Build() also exposes Configuration and Environment:

var app = builder.Build();
IConfiguration configuration = app.Configuration;
IWebHostEnvironment environment = app.Environment;

Also check the migration guide and code samples.