public override void Activate()
{
IDictionary <string, Lazy <object> > valuesLazy = ImportValues.ToDictionary(
x => x.Key.MemberName,
v => v.Value);
if (CachedInstance == null && this.Definition.ParameterlessConstructor)
{
_cachedInstance = CustomActivator.CreateInstance(Definition.GetPartType());
var unpackValues = valuesLazy.ToDictionary(k => k.Key, v => v.Value.Value);
CustomActivator.PopulateObjectProperties(_cachedInstance, unpackValues);
}
else if (this.Definition.ParameterlessConstructor)
{
var unpackValues = valuesLazy.ToDictionary(k => k.Key, v => v.Value.Value);
CustomActivator.PopulateObjectProperties(_cachedInstance, unpackValues);
}
else
{
var constructor = Definition.GetConstructor();
var requiredParameters = constructor.GetParameters();
//Sorting imports to match constructor order
object[] unpackValues = new SortedDictionary <string, Lazy <object> >(valuesLazy)
.Zip(requiredParameters, (lazyValues, required) => new { lazyValues, required })
.OrderBy(x => x.required.Name)
.Select(x => x.lazyValues.Value.Value)
.ToArray <object>();
_cachedInstance = Definition.GetConstructor().Invoke(unpackValues);
}
}
private bool TryGetImportValue(ImportDefinition definition, out object value)
{
lock (_lock)
{
if (_importValues != null && ImportValues.TryGetValue(definition, out value))
{
ImportValues.Remove(definition);
return(true);
}
}
value = null;
return(false);
}
// this is called under a lock
private void EnsureGettable()
{
// If we're already composed then we know that
// all pre-req imports have been satisfied
if (_initialCompositionComplete)
{
return;
}
// Make sure all pre-req imports have been set
foreach (ImportDefinition definition in ImportDefinitions.Where(definition => definition.IsPrerequisite))
{
if (_importValues == null || !ImportValues.ContainsKey(definition))
{
throw new InvalidOperationException(string.Format(CultureInfo.CurrentCulture,
SR.InvalidOperation_GetExportedValueBeforePrereqImportSet,
definition.ToElement().DisplayName));
}
}
}