使用 Json.NET 序列化时如何应用重新映射所有属性名称的一般规则？

Question

将 Json 对象反序列化为 .Net 时type，如果字段名称不匹配，我发现您可以type用以下方式装饰您的属性[JsonProperty(PropertyName = "name")]

对于一些不匹配的属性来说，这很好，但是有没有办法设置约定或规则呢？

杰森

{
  "Job": [
    {
      "Job #": "1",
      "Job Type": "A",
    }
  ]
}

C＃

    [JsonProperty(PropertyName = "Job Type")]
    public string JobType { get; set; }

    [JsonProperty(PropertyName = "Job #")]
    public string JobNumber { get; set; }

我有许多字段使用相似的名称，我想弄清楚，有没有办法告诉设置规则以始终删除空格（EG：）Job Type -> JobType并替换#为Number（例如Job # -> JobNumber：）？

看起来自定义ContractResolver可能是唯一的解决方案，但我似乎不知道如何使用它来删除空格并将“#”替换为“Number”。有人有参考示例吗？

或者，我希望有一个我忽略的简单的解决方案。

PS 还接受更好标题的建议。

Answer 1

假设您使用的是 Json.NET 9.0.1或更高版本，这可以通过自定义NamingStrategy. 例如，这是基于詹姆斯·牛顿·SnakeCaseNamingStrategy金StringUtils.ToSnakeCase()(James Newton-King) 的一篇文章：

public class CustomNamingStrategy : NamingStrategy
{
    public CustomNamingStrategy(bool processDictionaryKeys, bool overrideSpecifiedNames)
    {
        ProcessDictionaryKeys = processDictionaryKeys;
        OverrideSpecifiedNames = overrideSpecifiedNames;
    }

    public CustomNamingStrategy(bool processDictionaryKeys, bool overrideSpecifiedNames, bool processExtensionDataNames)
        : this(processDictionaryKeys, overrideSpecifiedNames)
    {
        ProcessExtensionDataNames = processExtensionDataNames;
    }

    public CustomNamingStrategy()
    {
    }

    protected override string ResolvePropertyName(string name)
    {
        return SpaceWords(name);
    }

    enum WordState
    {
        Start,
        Lower,
        Upper,
        NewWord
    }

    static string SpaceWords(string s)
    {
        // Adapted from StringUtils.ToSnakeCase()
        // https://github.com/JamesNK/Newtonsoft.Json/blob/master/Src/Newtonsoft.Json/Utilities/StringUtils.cs#L191
        // 
        // Copyright (c) 2007 James Newton-King
        //
        // Permission is hereby granted, free of charge, to any person
        // obtaining a copy of this software and associated documentation
        // files (the "Software"), to deal in the Software without
        // restriction, including without limitation the rights to use,
        // copy, modify, merge, publish, distribute, sublicense, and/or sell
        // copies of the Software, and to permit persons to whom the
        // Software is furnished to do so, subject to the following
        // conditions:
        //
        // The above copyright notice and this permission notice shall be
        // included in all copies or substantial portions of the Software.
        //
        // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
        // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
        // OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
        // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
        // HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
        // WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
        // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
        // OTHER DEALINGS IN THE SOFTWARE.

        char wordBreakChar = ' ';

        if (string.IsNullOrEmpty(s))
        {
            return s;
        }

        StringBuilder sb = new StringBuilder();
        WordState state = WordState.Start;

        for (int i = 0; i < s.Length; i++)
        {
            if (s[i] == ' ')
            {
                if (state != WordState.Start)
                {
                    state = WordState.NewWord;
                }
            }
            else if (char.IsUpper(s[i]))
            {
                switch (state)
                {
                    case WordState.Upper:
                        bool hasNext = (i + 1 < s.Length);
                        if (i > 0 && hasNext)
                        {
                            char nextChar = s[i + 1];
                            if (!char.IsUpper(nextChar) && nextChar != ' ')
                            {
                                sb.Append(wordBreakChar);
                            }
                        }
                        break;
                    case WordState.Lower:
                    case WordState.NewWord:
                        sb.Append(wordBreakChar);
                        break;
                }

                sb.Append(s[i]);

                state = WordState.Upper;
            }
            else if (s[i] == wordBreakChar)
            {
                sb.Append(wordBreakChar);
                state = WordState.Start;
            }
            else
            {
                if (state == WordState.NewWord)
                {
                    sb.Append(wordBreakChar);
                }

                sb.Append(s[i]);
                state = WordState.Lower;
            }
        }

        sb.Replace("Number", "#");
        return sb.ToString();
    }
}

然后您可以将其应用到您的类型，如下所示：

[JsonObject(NamingStrategyType = typeof(CustomNamingStrategy))]
public class RootObject
{
    public string JobType { get; set; }

    public string JobNumber { get; set; }

    public int JobItemCount { get; set; }

    public string ISOCode { get; set; }

    public string SourceXML { get; set; }
}

生成的 JSON 如下：

{
  "Job Type": "job type",
  "Job #": "01010101",
  "Job Item Count": 3,
  "ISO Code": "ISO 9000",
  "Source XML": "c:\temp.xml"
}

笔记：

• 如果您希望该策略应用于已通过 指定属性名称的属性JsonPropertyAttribute.PropertyName，请设置NamingStrategy.OverrideSpecifiedNames == true。

• 要将命名策略应用于所有类型而不是在每个对象上设置它，您可以在 中设置命名策略DefaultContractResolver.NamingStrategy，然后在 中设置契约解析器JsonSerializerSettings.ContractResolver。

• 命名策略从 C# 属性名称映射到 JSON 属性名称，反之亦然。因此，您需要插入空格而不是“将其拔出”并将“Number”替换为“#”。然后，映射由合约解析器缓存，并在反序列化期间完成反向查找。