ASP.NET Core Web App .NET 6, reading configuration from within a Razor pages' cs file - razor-pages

Question

I'm trying to find a simple way to access a value from the configuration of a .NET 6, ASP.NET Core Web App, in a Razor page's .cs file, using Visual Studio 2022. There's a lot of examples of how to do this online the old way. I'm trying to get up to speed with ASP.NET Core, and .NET 6, and I don't want to use the old techniques.
Right now I can connect to a SQLite database with a very simple configuration. Here's the code in my Index.cshtml.cs file,
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.Extensions.Configuration;
using System.Data.SQLite;
namespace Something.Pages
{
public class IndexModel : PageModel
{
private readonly ILogger<IndexModel> _logger;
public IndexModel(ILogger<IndexModel> logger)
{
_logger = logger;
}
public void OnGet()
{
var cnnStrBuilder = new SQLiteConnectonStringBuilder();
cnnStrBuild.DataSource = "DBFile.SQLite";
using (SQLiteConnection cnn = new(cnnStrBuilder.ConnectionString))
{
cnn.Open();
...
}
}
}
}
This works. I can read and display data without the need for a DBContext, or EntityFramework, or anything else. All I want to change is to get the connection string from the appsettings.json file. My appsettings.json looks like this,
{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
},
"ConnectionStrings": {
"MyConStr" : "DBFile.SQLite"
},
"AllowedHosts": "*"
}
in my Program.cs file is the builder object, which I could use to get the configuration.
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddRazorPages();
var app = builder.Build();
// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
app.UseExceptionHandler("/Error");
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.MapRazorPages();
app.Run();
but how do I get access to the builder object in the Razor page's .cs file so I can get to the configuration? .NET 6 is supposed to make things like this easier, I thought.
BTW, I purposefully left 'connection string' out of the title of this post because I feel like this should be a generic thing. It shouldn't be so hard to retrieve a string value from the configuration settings from anywhere in the application. What am I missing?

Answer 1

You can inject an instance of IConfiguration in your PageModel which you can use to access appsettings.json values.
public class IndexModel : PageModel
{
private readonly ILogger<IndexModel> _logger;
private readonly IConfiguration _configuration;
public IndexModel(ILogger<IndexModel> logger, IConfiguration configuration)
{
_logger = logger;
_configuration = configuration;
}
public void OnGet()
{
var cnnStrBuilder = new SQLiteConnectonStringBuilder();
cnnStrBuild.DataSource = _configuration.GetConnectionString("MyConStr");
using (SQLiteConnection cnn = new(cnnStrBuilder.ConnectionString))
{
cnn.Open();
...
}
}
}
You can also check this article for more info:
https://www.learnrazorpages.com/configuration/