ASP.NET IOptions example

IConfigurationExample.cs

// appsettings.json (Configuration)
{
  "BankingOptions": {
    "SavingsInterestRate": 3.5,
    "LoanLimit": 50000,
    "MinimumBalance": 1000
  }
}

// BankingService.cs (Service that Reads Configuration Directly)
public class BankingService
{
    private readonly IConfiguration _configuration;

    public BankingService(IConfiguration configuration)
    {
        _configuration = configuration;
    }

    public string GetBankingSettings()
    {
        var savingsInterestRate = _configuration.GetValue<double>("BankingOptions:SavingsInterestRate");
        var loanLimit = _configuration.GetValue<int>("BankingOptions:LoanLimit");
        var minimumBalance = _configuration.GetValue<int>("BankingOptions:MinimumBalance");

        return $"Savings Interest Rate: {savingsInterestRate}%\n" +
               $"Loan Limit: {loanLimit}\n" +
               $"Minimum Balance: {minimumBalance}";
    }
}

// Program.cs (ASP.NET Core Setup and Configuration)
var builder = WebApplication.CreateBuilder(args);

// Register BankingService directly
builder.Services.AddTransient<BankingService>();

var app = builder.Build();

// Minimal API to expose settings via /settings endpoint
app.MapGet("/settings", (BankingService bankingService) =>
{
    return bankingService.GetBankingSettings();
});

app.Run();

IOptionsExample.cs

// appsettings.json (Configuration)
{
  "BankingOptions": {
    "SavingsInterestRate": 3.5,
    "LoanLimit": 50000,
    "MinimumBalance": 1000
  }
}

// BankingOptions.cs (Options Class)
public class BankingOptions
{
    public double SavingsInterestRate { get; set; }
    public int LoanLimit { get; set; }
    public int MinimumBalance { get; set; }
}

// BankingService.cs (Service that Uses Options)
public class BankingService
{
    private readonly BankingOptions _options;

    public BankingService(IOptions<BankingOptions> options)
    {
        _options = options.Value;
    }

    public string GetBankingSettings()
    {
        return $"Savings Interest Rate: {_options.SavingsInterestRate}%\n" +
               $"Loan Limit: {_options.LoanLimit}\n" +
               $"Minimum Balance: {_options.MinimumBalance}";
    }
}

// Program.cs (ASP.NET Core Setup and Configuration)
var builder = WebApplication.CreateBuilder(args);

// Register strongly-typed options
builder.Services.Configure<BankingOptions>(
    builder.Configuration.GetSection("BankingOptions")
);

// Register the BankingService as Scoped
builder.Services.AddScoped<BankingService>();

var app = builder.Build();

// Minimal API to expose settings via /settings endpoint
app.MapGet("/settings", (BankingService bankingService) =>
{
    return bankingService.GetBankingSettings();
});

app.Run();