C# 如何让Json.NET将Int32转换为URI
在C#代码中,我希望使用设计为int的Int32属性,但在使用Json.NET转换为Json时,我希望将它们序列化为URI,这样我就不必将所有模型映射到另一个模型,只用于Json输出。e、 g.简化模型:C# 如何让Json.NET将Int32转换为URI,c#,json.net,C#,Json.net,在C#代码中,我希望使用设计为int的Int32属性,但在使用Json.NET转换为Json时,我希望将它们序列化为URI,这样我就不必将所有模型映射到另一个模型,只用于Json输出。e、 g.简化模型: public class Order { public int? AccountID { get; set; } public int ProductID { get; set; } public decimal Total { get; set; } } 我想把它呈
public class Order
{
public int? AccountID { get; set; }
public int ProductID { get; set; }
public decimal Total { get; set; }
}
我想把它呈现成这样:
{ "accountUri": "/account/123", "productUri": "/product/456", "total": 789.01 }
{ "productUri": "/product/456", "total": 789.01 }
请注意,大小写和属性重命名已更改
如果AccountID为null,则json必须如下呈现:
{ "accountUri": "/account/123", "productUri": "/product/456", "total": 789.01 }
{ "productUri": "/product/456", "total": 789.01 }
在C#代码中,我仍然希望像使用普通int一样使用属性,因此我考虑使用int运算符重写
我不想在模型属性上使用属性,但我很乐意为Int32使用包装器类,如果需要,也不介意在包装器类上使用属性
下面的代码与答案很接近,但您得到了要点:
public class Order
{
public AccountIdentifier AccountID { get; set; }
public ProductIdentifier ProductID { get; set; }
public decimal Total { get; set; }
}
public abstract class IdentifierBase
{
private readonly string _uriPrefix;
private int? _value;
protected IdentifierBase(string uriPrefix, int? value)
{
_uriPrefix = uriPrefix;
_value = value;
}
public override string ToString()
{
if (_value.HasValue)
return _uriPrefix + _value.Value;
return null;
}
// insert int operator overrides here.
}
public class AccountIdentifier : IdentifierBase
{
public AccountIdentifier(int? value)
: base("/account/", value)
{
}
}
public class ProductIdentifier : IdentifierBase
{
public ProductIdentifier(int? value)
: base("/product/", value)
{
}
}
[Test]
public void JsonConvert()
{
var order = new Order
{
AccountID = new AccountIdentifier(123),
ProductID = new ProductIdentifier(456),
Total = 789.01M
};
using (var stringWriter = new StringWriter())
{
var writer = new JsonTextWriter(stringWriter) {Formatting = Formatting.None};
var settings = new JsonSerializerSettings();
var serializer = JsonSerializer.Create(settings);
// Camel case the properties.
serializer.ContractResolver = new CamelCasePropertyNamesContractResolver();
serializer.Serialize(writer, order);
writer.Flush();
var json = stringWriter.GetStringBuilder().ToString();
Console.Write(json);
}
}
这将产生:
{"accountID":{},"productID":{},"total":789.01}
三个问题:
[TestFixture]
public class MyPoC
{
public class OrderJsonConverter : JsonConverter
{
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
writer.WriteStartObject();
var order = value as Order;
if (order.AccountID.HasValue)
{
writer.WritePropertyName("accountUri");
serializer.Serialize(writer, "/account/" + order.AccountID);
}
writer.WritePropertyName("productUri");
serializer.Serialize(writer, "/product/" + order.ProductID);
writer.WritePropertyName("total");
serializer.Serialize(writer, order.Total);
writer.WriteEndObject();
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
var order = new Order();
var jsonObject = JObject.Load(reader);
order.AccountID = jsonObject.GetNullableIntFromUri("accountUri");
order.ProductID = jsonObject.GetIntFromUri("productUri");
order.Total = jsonObject["total"].Value<decimal>();
return order;
}
public override bool CanConvert(Type objectType)
{
return typeof(Order).IsAssignableFrom(objectType);
}
}
[Test]
public void JsonConvert_Is_Successful()
{
var order = new Order
{
AccountID = 123,
ProductID = 456,
Total = 789.01M
};
var json = JsonConvert.SerializeObject(order, Formatting.None, new OrderJsonConverter());
Console.WriteLine(json);
var deserialized = JsonConvert.DeserializeObject<Order>(json, new OrderJsonConverter());
Console.WriteLine("AccountID: {0}", deserialized.AccountID);
Console.WriteLine("ProductID: {0}", deserialized.ProductID);
Console.WriteLine("Total: {0}", deserialized.Total);
}
}
}
public static class JObjectExtensions
{
public static int GetIntFromUri(this JObject jsonObject, string propertyName)
{
var id = jsonObject.GetNullableIntFromUri(propertyName);
return id.Value;
}
public static int? GetNullableIntFromUri(this JObject jsonObject, string propertyName)
{
var uri = jsonObject[propertyName].ToObject<string>();
var s = Regex.Replace(uri, @".*/(\d+)$", "$1");
int id;
if (int.TryParse(s, out id))
{
return id;
}
return null;
}
}
额外的工作将是验证uri是否正确,而不仅仅是一个通用的“从uri末尾删除id”。1)使用JsonProperty属性的PropertyName参数,例如:
[JsonProperty(PropertyName = "accountUri")]
public AccountIdentifier AccountID { get; set; }
2) {}是AccountIdentifier和ProductIdentifier类的内容。您需要为Order类编写自定义Json转换器,以便自定义(反)序列化内容
这是相关的
3) 您还可以通过JsonProperty进行设置
[JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
编辑:这里是Order类自定义JsonConvert的一部分。它不使用上述属性,而是手动处理。如果其他人能提供更好(更完整)的解决方案,请这样做
public class OrderJsonConverter : JsonConverter
{
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
writer.WriteStartObject();
var obj = value as Order;
writer.WritePropertyName("accountUri");
serializer.Serialize(writer, obj.AccountID.ToString());
writer.WritePropertyName("productUri");
serializer.Serialize(writer, obj.ProductID.ToString());
writer.WritePropertyName("Total");
serializer.Serialize(writer, obj.Total);
writer.WriteEndObject();
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
throw new NotImplementedException();
}
public override bool CanConvert(Type objectType)
{
return typeof(Order).IsAssignableFrom(objectType);
}
}
既然您决定考虑使用适配器模式,这里有一个示例实现:测试:
[TestFixture]
public class When_serializing_Order
{
[SetUp]
public void SetUp()
{
JsonConvert.DefaultSettings = () => new JsonSerializerSettings()
{
ContractResolver = new CamelCasePropertyNamesContractResolver(),
NullValueHandling = NullValueHandling.Ignore
};
}
[TestCase(123, 456, 789.01, "{\"accountUri\":\"/account/123\",\"productUri\":\"/product/456\",\"total\":789.01}")]
[TestCase(null, 456, 789.01, "{\"productUri\":\"/product/456\",\"total\":789.01}")]
public void Should_render_exact_json(int? accountId, int productId, decimal total, string expectedJson)
{
var order = new Order
{
AccountID = accountId,
ProductID = productId,
Total = total
};
string jsonOrder = JsonConvert.SerializeObject(new OrderAdapter(order));
Assert.That(jsonOrder, Is.EqualTo(expectedJson));
}
}
public class Order
{
public int? AccountID { get; set; }
public int ProductID { get; set; }
public decimal Total { get; set; }
}
public class OrderAdapter
{
private readonly Uri _accountUri;
private readonly Uri _productUri;
private readonly decimal _total;
public OrderAdapter(Order order)
{
_accountUri = order.AccountID != null ? CreateRelativeUri("account", order.AccountID.Value) : null;
_productUri = CreateRelativeUri("product", order.ProductID);
_total = order.Total;
}
public Uri AccountUri { get { return _accountUri; } }
public Uri ProductUri { get { return _productUri; } }
public decimal Total { get { return _total; } }
private Uri CreateRelativeUri(string resourceType, int id)
{
return new Uri(String.Format("/{0}/{1}", resourceType, id), UriKind.Relative);
}
}
如果您有任何问题,请发表评论,我将对任何需要进一步解释的内容进行注释。正确的解决方案是使用适配器模式。虽然这在技术上不是映射,但我怀疑您不会喜欢这样,因为您的声明“因此我不必为了json输出而将所有模型映射到另一个模型”。您还应该查看关注点分离。老实说,你真的应该重新考虑你对潜在解决方案的立场。你正在走一条没有多大意义的路,这条路很难走(而且会让其他开发人员感到困惑)。你应该已经使用完适配器模式,而不是等待答案。是的,我需要分离我的关注点。。。我将研究如何使用适配器模式。谢谢。我添加了一个答案来给你一个简明的例子。你的编辑是一个很好的答案。谢谢!编写所有覆盖需要做很多工作,但比第一个答案更容易接受,因为我不想使用属性。谢谢很好的解决方案。满足我的所有要求。。。esp没有属性。谢谢