如何从带参数的构造函数创建对象

Question

这段代码在默认构造函数中运行良好。如何从带参数的构造函数创建对象？

private readonly JsonSerializer _serializer;

private static readonly IReadOnlyDictionary<TypeId, Type> _derivedTypes;
        static ByTypeIdConverter()
        {
            var baseType = typeof(T);
            var assemblies = AppDomain.CurrentDomain.GetAssemblies();

            _derivedTypes = (
                    from domainAssembly in AppDomain.CurrentDomain.GetAssemblies()
                    from assemblyType in domainAssembly.GetTypes()
                    where !assemblyType.IsAbstract && assemblyType.IsSubclassOf(baseType)
                    select assemblyType).ToDictionary(t => (TypeId)t);
        }

public override T? ReadJson(JsonReader reader, Type objectType, T? existingValue, bool hasExistingValue, JsonSerializer serializer)
{
    var jObject = JObject.Load(reader);
    var typeId = jObject["_t"]?.ToObject<TypeId>();

    if (typeId is null || !_derivedTypes.TryGetValue(typeId, out var classType))
        throw new JsonSerializationException("Failed to get derived class type from json or found type was not expected");

    var creator = _serializer.ContractResolver.ResolveContract(classType).DefaultCreator;

    if (creator is null)
    {
        throw new JsonSerializationException($"Failed create instance of type {classType.Name}");
    }

    var result = creator();
    _serializer.Populate(jObject.CreateReader(), result);

    return (T)result;
}

一些附加信息我有 SomeBase class 和该基础的自定义 JsonConverter class。我只是像这样反序列化：

JsonConvert.DeserializeObject<SomeBase>(jsonData);

Answer 1

我创建了未初始化的对象。这帮助我解决了我的问题

if (creator is null)
                creator = () => RuntimeHelpers.GetUninitializedObject(classType);

如何从带参数的构造函数创建对象

How can I create object from constructors with parameters

c#

json

json.net

converters