public static MappedConstructor Map(ConstructorInfo constructor, IContainer container)
{
MappedConstructor mappedConstructor = new MappedConstructor(constructor);
var parameters = constructor.GetParameters();
mappedConstructor._serviceFuncs = new List <Func <object> >();
foreach (var parameter in parameters)
{
if (container.TryGetRegistration(parameter.ParameterType, out _))
{
if (typeof(IEnumerable).IsAssignableFrom(parameter.ParameterType))
{
mappedConstructor._serviceFuncs.Add(() => container.GetServices(parameter.ParameterType.GenericTypeArguments[0]));
}
else
{
mappedConstructor._serviceFuncs.Add(() => container.GetService(parameter.ParameterType));
}
}
else
{
mappedConstructor.IsValid = false;
break;
}
}
return(mappedConstructor);
}
public object Activate(IContainer container)
{
if (_constructors == null)
{
_constructors = ImplementationType.GetTypeInfo()
.DeclaredConstructors
.Where(c => c.IsPublic);
}
MappedConstructor constructor = PickConstrutor(container);
return(constructor.Activate());
}
private MappedConstructor PickConstrutor(IContainer container)
{
List <MappedConstructor> mappedConstructors = new List <MappedConstructor>();
foreach (var constructor in _constructors)
{
MappedConstructor mappedConstructor = MappedConstructor.Map(constructor, container);
if (mappedConstructor.IsValid)
{
mappedConstructors.Add(mappedConstructor);
}
}
if (!mappedConstructors.Any())
{
throw new ArgumentException($"No valid constructors for {ImplementationType.FullName}.");
}
else if (mappedConstructors.Count == 1)
{
return(mappedConstructors.First());
}
else
{
var maxParameterConstrutors = mappedConstructors.GroupBy(
c => c.Constructor.GetParameters().Length,
c => c,
(key, grp) => new { ParamCount = key, Construtors = grp.ToList() })
.OrderByDescending(c => c.ParamCount)
.First();
if (maxParameterConstrutors.Construtors.Count == 1)
{
return(maxParameterConstrutors.Construtors.First());
}
else
{
throw new ArgumentException($"Multiple constructors with the same number of parameters for type {mappedConstructors.First().Constructor.DeclaringType}");
}
}
}
