在沒有你的問題的Minimal, Complete, and Verifiable example的,我會假設你正試圖反序列化類的列表看起來像這樣:
public class Vehicle
{
public string Id { get; set; }
[XmlElement(IsNullable = true)]
public DateTime? RenewalDate { get; set; }
}
public class RootObject
{
public Vehicle Vehicle { get; set; }
}
而且,反序列化失敗的屬性"RenewalDate"
,因爲不存在JSON中出現的null
值,因此存在包含翻譯的xsi:nil="true"
屬性的對象。要解決這個
一種方式是引進以下custom JsonConverter
:
public class NullableStructConverter<T> : JsonConverter where T : struct
{
public override bool CanConvert(Type objectType)
{
return objectType == typeof(Nullable<T>);
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
var underlyingType = Nullable.GetUnderlyingType(objectType);
if (underlyingType == null)
throw new InvalidOperationException(string.Format("Type {0} is not nullable", objectType));
var token = JToken.Load(reader);
if (token.Type == JTokenType.Null)
return null;
if (token.WasNilXmlElement())
return null;
return token.ToObject(underlyingType, serializer);
}
public override bool CanWrite { get { return false; } }
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
throw new NotImplementedException();
}
}
public static partial class JTokenExtensions
{
public static bool WasNilXmlElement(this JToken token)
{
if (token == null)
return true;
if (token.Type == JTokenType.Null)
return true;
var obj = token as JObject;
if (obj != null)
{
// Check if all properties were translated from XML attributes
// and one was translated from xsi:nil = true
// There might be namespaces present as well, e.g.
// "@xmlns:p3": "http://www.w3.org/2001/XMLSchema-instance"
if (obj.Properties().All(p => p.Name.StartsWith("@"))
&& obj.Properties().Any(p => p.Name == "@nil" || p.Name.EndsWith(":nil") && p.Value.ToString() == "true"))
return true;
}
return false;
}
}
然後反序列化如下:
var settings = new JsonSerializerSettings
{
Converters = { new NullableStructConverter<DateTime>() }
// Whatever other settings you require.
};
var root = JsonConvert.DeserializeObject<RootObject[]>(json, settings);
工作.Net fiddle。
另一種選擇是將JSON裝載到JToken
層次結構,取代了從null
JSON值nil
XML元素翻譯所有JSON對象,然後最後反序列化到模型。首先,介紹其使用WasNilXmlElement()
從第一溶液中以下擴展方法:
public static partial class JTokenExtensions
{
public static JToken ReplaceNilXmlElementObjectsWithNull(this JToken root)
{
var rootContainer = root as JContainer;
if (rootContainer == null)
return root;
var list = rootContainer.DescendantsAndSelf()
.OfType<JObject>()
.Where(o => o.WasNilXmlElement())
.ToList();
foreach (var obj in list)
{
var replacement = JValue.CreateNull();
if (obj.Parent != null)
obj.Replace(replacement);
if (root == obj)
root = replacement;
}
return root;
}
}
和反序列化如下:
var settings = new JsonSerializerSettings
{
// Whatever settings you require.
};
var root = JsonConvert.DeserializeObject<JToken>(json, settings)
.ReplaceNilXmlElementObjectsWithNull()
.ToObject<RootObject[]>(JsonSerializer.CreateDefault(settings));
該溶液避免了對JsonConverter
每個空類型的需要。工作fiddle #2。
來源
2017-07-16 06:32:28
dbc
當原始XML中不是'nil'時,'''RenewalDate''的值是什麼?你試圖將JSON反序列化爲什麼樣的c#模型?如果你只是做'JToken.Parse(jsonString)'它應該可以正常工作,所以請分享你的目標模型的反序列化失敗。 – dbc
這個[mcve]有沒有機會?如果您向我們展示了迄今爲止所做的工作以及確切的失敗位置,我們更有可能爲您提供可實際使用的解決方案。見[問]和https://codeblog.jonskeet.uk/2010/08/29/writing-the-perfect-question/。 – dbc