使用 Json.NET 的 Pascal 案例动态属性

Pascal case dynamic properties with Json.NET(使用 Json.NET 的 Pascal 案例动态属性)
本文介绍了使用 Json.NET 的 Pascal 案例动态属性的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着跟版网的小编来一起学习吧!

问题描述

这就是我所拥有的:

using Newtonsoft.Json;

var json = "{"someProperty":"some value"}";
dynamic deserialized = JsonConvert.DeserializeObject(json);

这很好用:

Assert.That(deserialized.someProperty.ToString(), Is.EqualTo("some value"));

我希望它在不改变 json 的情况下工作(属性的第一个字母大写):

I want this to work (first letter of properties upper-cased) without changing json:

Assert.That(deserialized.SomeProperty.ToString(), Is.EqualTo("some value"));

推荐答案

我同意 Avner Shahar-Kashtan 的观点.您不应该这样做,尤其是在您无法控制 JSON 的情况下.

I agree with Avner Shahar-Kashtan. You shouldn't be doing this, especially if you have no control over the JSON.

也就是说,可以使用 ExpandoObject 和自定义 ExpandoObjectConverter.JSON.NET 已经提供了一个 ExpandoObjectConverter 所以稍微调整一下有你想要的.

That said, it can be done with the use of a ExpandoObject and a custom ExpandoObjectConverter. JSON.NET already provides a ExpandoObjectConverter so with some little adjustments you have what you want.

注意代码片段中的 //CHANGED 注释,以显示我在哪里更改.

Notice the //CHANGED comments inside the code snippet to show you where I changed it.

public class CamelCaseToPascalCaseExpandoObjectConverter : JsonConverter
{
  //CHANGED
  //the ExpandoObjectConverter needs this internal method so we have to copy it
  //from JsonReader.cs
  internal static bool IsPrimitiveToken(JsonToken token) 
  {
      switch (token)
      {
          case JsonToken.Integer:
          case JsonToken.Float:
          case JsonToken.String:
          case JsonToken.Boolean:
          case JsonToken.Null:
          case JsonToken.Undefined:
          case JsonToken.Date:
          case JsonToken.Bytes:
              return true;
          default:
              return false;
      }
  }

/// <summary>
/// Writes the JSON representation of the object.
/// </summary>
/// <param name="writer">The <see cref="JsonWriter"/> to write to.</param>
/// <param name="value">The value.</param>
/// <param name="serializer">The calling serializer.</param>
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
  // can write is set to false
}

/// <summary>
/// Reads the JSON representation of the object.
/// </summary>
/// <param name="reader">The <see cref="JsonReader"/> to read from.</param>
/// <param name="objectType">Type of the object.</param>
/// <param name="existingValue">The existing value of object being read.</param>
/// <param name="serializer">The calling serializer.</param>
/// <returns>The object value.</returns>
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
  return ReadValue(reader);
}

private object ReadValue(JsonReader reader)
{
  while (reader.TokenType == JsonToken.Comment)
  {
    if (!reader.Read())
      throw new Exception("Unexpected end.");
  }

  switch (reader.TokenType)
  {
    case JsonToken.StartObject:
      return ReadObject(reader);
    case JsonToken.StartArray:
      return ReadList(reader);
    default:
      //CHANGED
      //call to static method declared inside this class
      if (IsPrimitiveToken(reader.TokenType))
        return reader.Value;

      //CHANGED
      //Use string.format instead of some util function declared inside JSON.NET
      throw new Exception(string.Format(CultureInfo.InvariantCulture, "Unexpected token when converting ExpandoObject: {0}", reader.TokenType));
  }
}

private object ReadList(JsonReader reader)
{
  IList<object> list = new List<object>();

  while (reader.Read())
  {
    switch (reader.TokenType)
    {
      case JsonToken.Comment:
        break;
      default:
        object v = ReadValue(reader);

        list.Add(v);
        break;
      case JsonToken.EndArray:
        return list;
    }
  }

  throw new Exception("Unexpected end.");
}

private object ReadObject(JsonReader reader)
{
  IDictionary<string, object> expandoObject = new ExpandoObject();

  while (reader.Read())
  {
    switch (reader.TokenType)
    {
      case JsonToken.PropertyName:
        //CHANGED
        //added call to ToPascalCase extension method       
        string propertyName = reader.Value.ToString().ToPascalCase();

        if (!reader.Read())
          throw new Exception("Unexpected end.");

        object v = ReadValue(reader);

        expandoObject[propertyName] = v;
        break;
      case JsonToken.Comment:
        break;
      case JsonToken.EndObject:
        return expandoObject;
    }
  }

  throw new Exception("Unexpected end.");
}

/// <summary>
/// Determines whether this instance can convert the specified object type.
/// </summary>
/// <param name="objectType">Type of the object.</param>
/// <returns>
///     <c>true</c> if this instance can convert the specified object type; otherwise, <c>false</c>.
/// </returns>
public override bool CanConvert(Type objectType)
{
  return (objectType == typeof (ExpandoObject));
}

/// <summary>
/// Gets a value indicating whether this <see cref="JsonConverter"/> can write JSON.
/// </summary>
/// <value>
///     <c>true</c> if this <see cref="JsonConverter"/> can write JSON; otherwise, <c>false</c>.
/// </value>
public override bool CanWrite
{
  get { return false; }
}
}

一个简单的字符串到 Pascal 大小写转换器.如果需要,让它更智能.

A simple string to Pascal Case converter. Make it smarter if you need to.

public static class StringExtensions
{
    public static string ToPascalCase(this string s)
    {
        if (string.IsNullOrEmpty(s) || !char.IsLower(s[0]))
            return s;

        string str = char.ToUpper(s[0], CultureInfo.InvariantCulture).ToString((IFormatProvider)CultureInfo.InvariantCulture);

        if (s.Length > 1)
            str = str + s.Substring(1);

        return str;
    }
}

现在你可以像这样使用它了.

Now you can use it like this.

var settings = new JsonSerializerSettings()
                   {
                       ContractResolver = new CamelCasePropertyNamesContractResolver(),
                       Converters = new List<JsonConverter> { new CamelCaseToPascalCaseExpandoObjectConverter() }
                   };

var json = "{"someProperty":"some value"}";

dynamic deserialized = JsonConvert.DeserializeObject<ExpandoObject>(json, settings);

Console.WriteLine(deserialized.SomeProperty); //some value

var json2 = JsonConvert.SerializeObject(deserialized, Formatting.None, settings);

Console.WriteLine(json == json2); //true

ContractResolver CamelCasePropertyNamesContractResolver在将对象序列化回 JSON 并再次使其成为 Camel 大小写时使用.这也由 JSON.NET 提供.如果不需要,可以省略.

The ContractResolver CamelCasePropertyNamesContractResolver is used when serializing the object back to JSON and makes it Camel case again. This is also provided by JSON.NET. If you don't need this you can omit it.

这篇关于使用 Json.NET 的 Pascal 案例动态属性的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持跟版网!

本站部分内容来源互联网,如果有图片或者内容侵犯了您的权益,请联系我们,我们会在确认后第一时间进行删除!

相关文档推荐

Force JsonConvert.SerializeXmlNode to serialize node value as an Integer or a Boolean(强制 JsonConvert.SerializeXmlNode 将节点值序列化为整数或布尔值)
Using JSON to Serialize/Deserialize TimeSpan(使用 JSON 序列化/反序列化 TimeSpan)
Could not determine JSON object type for type quot;Classquot;(无法确定类型“Class的 JSON 对象类型.)
How to deserialize a JSONP response (preferably with JsonTextReader and not a string)?(如何反序列化 JSONP 响应(最好使用 JsonTextReader 而不是字符串)?)
how to de-serialize JSON data in which Timestamp it-self contains fields?(如何反序列化时间戳本身包含字段的JSON数据?)
JSON.Net custom contract serialization and Collections(JSON.Net 自定义合约序列化和集合)