#Overview#
Shows using the new project configuration API from ASP.NET Core in any project (not just ASP.NET Core) as well as a little extension method for hooking it up to SimpleInjector to use the Options pattern.
Check out https://docs.asp.net/en/latest/fundamentals/configuration.html
#Usage#
class Program
{
public static IConfigurationRoot Configuration { get; private set; }
static void Main(string[] args)
{
var builder = new ConfigurationBuilder();
builder.SetBasePath(Directory.GetCurrentDirectory())
.AddXmlFile("App.config", optional: true, reloadOnChange: true)
.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);
builder.AddEnvironmentVariables();
Configuration = builder.Build();
var simple = new SimpleInjector.Container();
simple.AddOptions(Configuration);
foreach (var v in Configuration.AsEnumerable())
{
Console.WriteLine($"{v.Key} : {v.Value}");
}
var dbOptions = simple.GetInstance<IOptions<DatabaseSettings>>();
Console.WriteLine($"DB Name : {dbOptions.Value.Name}");
Console.ReadKey();
}
}#The Extension Method#
public static void AddOptions(this Container container, IConfiguration configuration)
{
container.ResolveUnregisteredType += (sender, e) =>
{
if (e.UnregisteredServiceType.IsGenericType &&
e.UnregisteredServiceType.GetGenericTypeDefinition() == typeof(IOptions<>))
{
var argType = e.UnregisteredServiceType.GenericTypeArguments.First();
var optionsType = typeof(IOptions<>).MakeGenericType(argType);
var concreteOptionsType = typeof(OptionsWrapper<>).MakeGenericType(argType);
var optionValue = Activator.CreateInstance(argType);
PopulateSettingObject(configuration, argType, optionValue);
var options = Activator.CreateInstance(concreteOptionsType, optionValue);
e.Register(() => options);
}
};
}
private static void PopulateSettingObject<T>(IConfiguration configuration, Type argType, T optionValue) where T : class, new()
{
var props = argType.GetProperties();
foreach (var p in props)
{
var name = p.Name;
var value = configuration[name];
p.SetValue(optionValue, value);
}
}