private static object Create(Cat cat, Type type, Type[] genericArguments)
{
if (genericArguments.Length > 0)
{
type = type.MakeGenericType(genericArguments);
}
var constructors = type.GetConstructors();
if (constructors.Length == 0)
{
throw new InvalidOperationException($"Cannot create the instance of {type} which does not have an public constructor.");
}
var constructor = constructors.FirstOrDefault(it => it.GetCustomAttributes(false).OfType <InjectionAttribute>().Any());
constructor ??= constructors.First();
var parameters = constructor.GetParameters();
if (parameters.Length == 0)
{
return(Activator.CreateInstance(type));
}
var arguments = new object[parameters.Length];
for (int index = 0; index < arguments.Length; index++)
{
arguments[index] = cat.GetService(parameters[index].ParameterType);
}
return(constructor.Invoke(arguments));
}
static void Main(string[] args)
{
var cat = new Cat()
.Register <IFoo, Foo>(Lifetime.Transient)
.Register <IBar, Bar>(Lifetime.Transient)
.Register(typeof(IFoobar <,>), typeof(Foobar <,>), Lifetime.Transient);
var foobar = (Foobar <IFoo, IBar>)cat.GetService <IFoobar <IFoo, IBar> >();
Debug.Assert(foobar.Foo is Foo);
Debug.Assert(foobar.Bar is Bar);
}
private static void GetGenericService()
{
var cat = new Cat()
.Register <IFoo, Foo>(Lifetime.Transient)
.Register <IBar, Bar>(Lifetime.Transient)
.Register(typeof(IFoobar <,>), typeof(Foobar <,>), Lifetime.Transient);
var foobar = (Foobar <IFoo, IBar>)cat.GetService <IFoobar <IFoo, IBar> >();
Debug.Assert(foobar.Foo is Foo);
Debug.Assert(foobar.Bar is Bar);
}
public static IEnumerable <T> GetServices <T>(this Cat cat) => cat.GetService <IEnumerable <T> >();
public static T GetService <T>(this Cat cat) => (T)cat.GetService(typeof(T));