C#中使用NewtonSoft将MyObject转为指定格式XML的问题

自定义对象定义 #

public class MyObject
{
    public string OrderId { get; set; }
    public string Installment { get; set; }
    public string Amount { get; set; }
    public List<Product> Products { get; set; }
}
public class Product
{
    public string ProductCode { get; set; }
    public string ProductName { get; set; }
    public string Quantity { get; set; }
    public string Price { get; set; }
}

当前转换方式及问题 #

通过先将对象序列化为JSON，再转换为XML的方式处理，但输出的XML中集合元素直接重复父节点名称（<products>），而非期望的<products>包裹多个<product>子节点。

辅助类代码 #

public static XNode XmlSerialize<T>(T ToXml, string root, JsonSerializerSettings settings)
{
    var ToJson = JsonConvert.SerializeObject(ToXml, Newtonsoft.Json.Formatting.Indented, settings);
    return JsonConvert.DeserializeXNode(ToJson, root);
}

public static JsonSerializerSettings DefaultJsonSerializerSettings()
{
    return new JsonSerializerSettings { 
        ContractResolver = new CamelCasePropertyNamesContractResolver(),
        DefaultValueHandling = DefaultValueHandling.Ignore,
        NullValueHandling = NullValueHandling.Ignore
    };
}

测试代码 #

static void Main(string[] args)
{
    XNode xml = Helper.XmlSerialize<MyObject>(new MyObject{ 
        Amount = "100", 
        OrderId = "123123123", 
        Installment="1", 
        Products = new List<Product> { 
            new Product { ProductName = "Test", Price = "100" }, 
            new Product { ProductName = "Test2", Price = "200" } 
        } 
    }, "auth", Helper.DefaultJsonSerializerSettings());

    Console.WriteLine(xml.ToString());
    Console.ReadKey();
}

当前输出XML #

<auth>
  <orderId>123123123</orderId>
  <installment>1</installment>
  <amount>100</amount>
  <products>
    <productName>Test</productName>
    <price>100</price>
  </products>
  <products>
    <productName>Test2</productName>
    <price>200</price>
  </products>
</auth>

期望输出XML #

<auth>
  <orderId>123123123</orderId>
  <installment>1</installment>
  <amount>100</amount>
  <products>
   <product>
    <productName>Test</productName>
    <price>100</price>
   </product>
   <product>
    <productName>Test2</productName>
    <price>200</price>
   </product>
  </products>
</auth>

解决方案 #

方案1：修改类的JSON序列化特性 #

给Product类添加[JsonObject("product")]特性，让JSON序列化时每个集合元素被标记为product，转换为XML时自动生成<product>节点：

[JsonObject("product")]
public class Product
{
    public string ProductCode { get; set; }
    public string ProductName { get; set; }
    public string Quantity { get; set; }
    public string Price { get; set; }
}

修改后重新运行原测试代码，即可得到期望的XML格式。

方案2：直接使用XML序列化（跳过JSON转换） #

放弃JSON中转步骤，直接用System.Xml.Serialization.XmlSerializer进行序列化，更直接且易控制格式：

1. 修改MyObject类，添加XmlArrayItem特性指定集合子节点名称：

public class MyObject
{
    public string OrderId { get; set; }
    public string Installment { get; set; }
    public string Amount { get; set; }
    [XmlArrayItem("product")]
    public List<Product> Products { get; set; }
}

2. 新增直接序列化的辅助方法：

public static XNode XmlSerializeDirect<T>(T obj, string rootName)
{
    var serializer = new XmlSerializer(typeof(T), new XmlRootAttribute(rootName));
    using (var writer = new StringWriter())
    {
        serializer.Serialize(writer, obj);
        return XDocument.Parse(writer.ToString());
    }
}

3. 修改测试代码调用新方法：

static void Main(string[] args)
{
    XNode xml = Helper.XmlSerializeDirect<MyObject>(new MyObject{ 
        Amount = "100", 
        OrderId = "123123123", 
        Installment="1", 
        Products = new List<Product> { 
            new Product { ProductName = "Test", Price = "100" }, 
            new Product { ProductName = "Test2", Price = "200" } 
        } 
    }, "auth");

    Console.WriteLine(xml.ToString());
    Console.ReadKey();
}

运行后即可生成符合预期的XML结构。

内容的提问来源于stack exchange，提问作者Fırat Kuas