使用 JSON 模式正确创建 .NET 类答案

【问题标题】：Correctly create a .NET class with a JSON schema使用 JSON 模式正确创建 .NET 类
【发布时间】：2020-03-11 16:13:17
【问题描述】：

我有一个带有 http://json-schema.org/ 的 JSON 模式

我正在尝试使用一些自动工具或通过 C# 代码将其转换为一个类，以避免手动工作。假设这是我的输入 JSON：

{
   "$schema":"http://json-schema.org/draft-04/schema#",
   "title":"test Schema",
   "type":"object",
   "properties":{
      "code":{
         "type":"string",
         "description":"..."
      },
      "success":{
         "type":"integer",
         "minimum":0,
         "maximum":1,
         "description":"..."
      },
      "status":{
         "type":"string",
         "enum":[
            "A",
            "B",
            "C"
         ],
         "description":""
      },
      "quantity":{
         "type":"number",
         "minimum":0,
         "description":"..."
      },
      "utcTimestamp":{
         "type":"string",
         "format":"date-time",
         "description":"..."
      }
   },
   "required":[
      "code",
      "success",
      "status",
      "quantity",
      "utcTimestamp"
   ]
}

我编写了一个简单的程序，使用 NJsonSchema.CodeGeneration.CSharp 从中生成一个 C# 类：

using NJsonSchema;
using NJsonSchema.CodeGeneration.CSharp;
using System.IO;
namespace JsonToClass
{
    class Program
    {
        static void Main(string[] args)
        {
            string json = File.ReadAllText("input.json");
            var schemaFromFile = JsonSchema.FromSampleJson(json);
            var classGenerator = new CSharpGenerator(schemaFromFile, new CSharpGeneratorSettings
            {
                ClassStyle = CSharpClassStyle.Poco
            });
            var codeFile = classGenerator.GenerateFile();
            File.WriteAllText("output.cs", codeFile);
        }
    }
}

输出是：

//----------------------
// <auto-generated>
//     Generated using the NJsonSchema v10.1.2.0 (Newtonsoft.Json v9.0.0.0) (http://NJsonSchema.org)
// </auto-generated>
//----------------------

namespace MyNamespace
{
    #pragma warning disable // Disable all warnings

    [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "10.1.2.0 (Newtonsoft.Json v9.0.0.0)")]
    public partial class Properties 
    {
        [Newtonsoft.Json.JsonProperty("code", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public Code Code { get; set; }

        [Newtonsoft.Json.JsonProperty("success", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public Success Success { get; set; }

        [Newtonsoft.Json.JsonProperty("status", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public Status Status { get; set; }

        [Newtonsoft.Json.JsonProperty("quantity", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public Success Quantity { get; set; }

        [Newtonsoft.Json.JsonProperty("utcTimestamp", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public UtcTimestamp UtcTimestamp { get; set; }

        private System.Collections.Generic.IDictionary<string, object> _additionalProperties = new System.Collections.Generic.Dictionary<string, object>();

        [Newtonsoft.Json.JsonExtensionData]
        public System.Collections.Generic.IDictionary<string, object> AdditionalProperties
        {
            get { return _additionalProperties; }
            set { _additionalProperties = value; }
        }


    }

    [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "10.1.2.0 (Newtonsoft.Json v9.0.0.0)")]
    public partial class Code 
    {
        [Newtonsoft.Json.JsonProperty("type", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Type { get; set; }

        [Newtonsoft.Json.JsonProperty("description", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Description { get; set; }

        private System.Collections.Generic.IDictionary<string, object> _additionalProperties = new System.Collections.Generic.Dictionary<string, object>();

        [Newtonsoft.Json.JsonExtensionData]
        public System.Collections.Generic.IDictionary<string, object> AdditionalProperties
        {
            get { return _additionalProperties; }
            set { _additionalProperties = value; }
        }


    }

    [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "10.1.2.0 (Newtonsoft.Json v9.0.0.0)")]
    public partial class Success 
    {
        [Newtonsoft.Json.JsonProperty("type", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Type { get; set; }

        [Newtonsoft.Json.JsonProperty("minimum", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public int Minimum { get; set; }

        [Newtonsoft.Json.JsonProperty("maximum", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public int Maximum { get; set; }

        [Newtonsoft.Json.JsonProperty("description", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Description { get; set; }

        private System.Collections.Generic.IDictionary<string, object> _additionalProperties = new System.Collections.Generic.Dictionary<string, object>();

        [Newtonsoft.Json.JsonExtensionData]
        public System.Collections.Generic.IDictionary<string, object> AdditionalProperties
        {
            get { return _additionalProperties; }
            set { _additionalProperties = value; }
        }


    }

    [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "10.1.2.0 (Newtonsoft.Json v9.0.0.0)")]
    public partial class Status 
    {
        [Newtonsoft.Json.JsonProperty("type", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Type { get; set; }

        [Newtonsoft.Json.JsonProperty("enum", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public System.Collections.Generic.ICollection<string> Enum { get; set; }

        [Newtonsoft.Json.JsonProperty("description", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Description { get; set; }

        private System.Collections.Generic.IDictionary<string, object> _additionalProperties = new System.Collections.Generic.Dictionary<string, object>();

        [Newtonsoft.Json.JsonExtensionData]
        public System.Collections.Generic.IDictionary<string, object> AdditionalProperties
        {
            get { return _additionalProperties; }
            set { _additionalProperties = value; }
        }


    }

    [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "10.1.2.0 (Newtonsoft.Json v9.0.0.0)")]
    public partial class UtcTimestamp 
    {
        [Newtonsoft.Json.JsonProperty("type", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Type { get; set; }

        [Newtonsoft.Json.JsonProperty("format", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Format { get; set; }

        [Newtonsoft.Json.JsonProperty("description", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Description { get; set; }

        private System.Collections.Generic.IDictionary<string, object> _additionalProperties = new System.Collections.Generic.Dictionary<string, object>();

        [Newtonsoft.Json.JsonExtensionData]
        public System.Collections.Generic.IDictionary<string, object> AdditionalProperties
        {
            get { return _additionalProperties; }
            set { _additionalProperties = value; }
        }


    }

    [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "10.1.2.0 (Newtonsoft.Json v9.0.0.0)")]
    public partial class Anonymous 
    {
        [Newtonsoft.Json.JsonProperty("$schema", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Schema { get; set; }

        [Newtonsoft.Json.JsonProperty("title", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Title { get; set; }

        [Newtonsoft.Json.JsonProperty("type", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Type { get; set; }

        [Newtonsoft.Json.JsonProperty("properties", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public Properties Properties { get; set; }

        [Newtonsoft.Json.JsonProperty("required", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public System.Collections.Generic.ICollection<string> Required { get; set; }

        private System.Collections.Generic.IDictionary<string, object> _additionalProperties = new System.Collections.Generic.Dictionary<string, object>();

        [Newtonsoft.Json.JsonExtensionData]
        public System.Collections.Generic.IDictionary<string, object> AdditionalProperties
        {
            get { return _additionalProperties; }
            set { _additionalProperties = value; }
        }


    }
}

和我预想的不太一样……比如第一个属性必须是一个叫code的字符串，但是这里创建了一个Code类型的code属性，里面有很多无用的东西，你可以看到。

然后，我想要一个 int 状态、枚举状态、十进制/浮点数和 utcTimestamp 字符串……可以吗？如何？我犯了一些错误吗？

我还测试了 Visual Studio - -> 编辑 -> 选择性粘贴 -> 将 JSON 粘贴为类，但结果是一样的。

【问题讨论】：

我认为您的输出比您意识到的更正确。 “代码”确实是一个对象，它应该由一个具有两个字符串属性——“类型”和“描述”的类来表示。但是，我不能对字典属性说话。
看起来 AdditionalProperties 可能被添加为模型无法识别的 JSON 中的那些属性的“包罗万象”。如果您不想要，可能有一个设置可以排除它。
@aardvark 我不这么认为......例如，对于第一个，我需要一个名为“code”的字符串......不需要类型和描述......
好吧，那么您的 JSON 不正确。您的 JSON 描述了一个对象，该对象包含一个名为“properties”的对象，该对象具有一个名为“code”的属性，它也是一个对象。
不幸的是，这个 json 是我与文档捆绑在一起的。无论如何，找到了解决方案：手动编写类......是的！

标签： c# json class jsonschema

【解决方案1】：

从 json 文件生成架构：

var schemaFromFile = JsonSchema.FromSampleJson(json)

从 json-schema 文件创建模式：

var schema = await JsonSchema.FromFileAsync(jsonSchemaFilePath)

【讨论】：