如何从ASP.NET MVC控制器方法返回由JSON.NET序列化的camelCase JSON？

我的问题是我希望通过ActionResult从ASP.NET MVC控制器方法（由JSON.NET序列化）中返回camelCased（与标准PascalCase相反）JSON数据。

作为示例，请考虑以下C＃类：

public class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

默认情况下，当从MVC控制器以JSON返回此类的实例时，它将以以下方式序列化：

{
  "FirstName": "Joe",
  "LastName": "Public"
}

我希望将其序列化（通过JSON.NET）为：

{
  "firstName": "Joe",
  "lastName": "Public"
}

我该怎么做呢？

或者，简单地说：

JsonConvert.SerializeObject(
    <YOUR OBJECT>, 
    new JsonSerializerSettings 
    { 
        ContractResolver = new CamelCasePropertyNamesContractResolver() 
    });

例如：

return new ContentResult
{
    ContentType = "application/json",
    Content = JsonConvert.SerializeObject(new { content = result, rows = dto }, new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() }),
    ContentEncoding = Encoding.UTF8
};

我在Mats Karlsson的博客中找到了解决此问题的绝佳方法。解决方案是编写ActionResult的子类，该子类通过JSON.NET序列化数据，并将后者配置为遵循camelCase约定：

public class JsonCamelCaseResult : ActionResult
{
    public JsonCamelCaseResult(object data, JsonRequestBehavior jsonRequestBehavior)
    {
        Data = data;
        JsonRequestBehavior = jsonRequestBehavior;
    }

    public Encoding ContentEncoding { get; set; }

    public string ContentType { get; set; }

    public object Data { get; set; }

    public JsonRequestBehavior JsonRequestBehavior { get; set; }

    public override void ExecuteResult(ControllerContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("context");
        }
        if (JsonRequestBehavior == JsonRequestBehavior.DenyGet && String.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase))
        {
            throw new InvalidOperationException("This request has been blocked because sensitive information could be disclosed to third party web sites when this is used in a GET request. To allow GET requests, set JsonRequestBehavior to AllowGet.");
        }

        var response = context.HttpContext.Response;

        response.ContentType = !String.IsNullOrEmpty(ContentType) ? ContentType : "application/json";
        if (ContentEncoding != null)
        {
            response.ContentEncoding = ContentEncoding;
        }
        if (Data == null)
            return;

        var jsonSerializerSettings = new JsonSerializerSettings
        {
            ContractResolver = new CamelCasePropertyNamesContractResolver()
        };
        response.Write(JsonConvert.SerializeObject(Data, jsonSerializerSettings));
    }
}

然后在MVC控制器方法中按如下所示使用此类：

public ActionResult GetPerson()
{
    return new JsonCamelCaseResult(new Person { FirstName = "Joe", LastName = "Public" }, JsonRequestBehavior.AllowGet)};
}

对于WebAPI，请查看以下链接：http : //odetocode.com/blogs/scott/archive/2013/03/25/asp-net-webapi-tip-3-camelcasing-json.aspx

基本上，将此代码添加到您的Application_Start：

var formatters = GlobalConfiguration.Configuration.Formatters;
var jsonFormatter = formatters.JsonFormatter;
var settings = jsonFormatter.SerializerSettings;
settings.ContractResolver = new CamelCasePropertyNamesContractResolver();

我认为这是您正在寻找的简单答案。它来自Shawn Wildermuth的博客：

// Add MVC services to the services container.
services.AddMvc()
  .AddJsonOptions(opts =>
  {
    opts.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
  });

自定义过滤器的替代方法是创建一个扩展方法，以将任何对象序列化为JSON。

public static class ObjectExtensions
{
    /// <summary>Serializes the object to a JSON string.</summary>
    /// <returns>A JSON string representation of the object.</returns>
    public static string ToJson(this object value)
    {
        var settings = new JsonSerializerSettings
        {
            ContractResolver = new CamelCasePropertyNamesContractResolver(),
            Converters = new List<JsonConverter> { new StringEnumConverter() }
        };

        return JsonConvert.SerializeObject(value, settings);
    }
}

然后从控制器操作返回时调用它。

return Content(person.ToJson(), "application/json");

IMO越简单越好！

你为什么不这样做呢？

public class CourseController : JsonController
{
    public ActionResult ManageCoursesModel()
    {
        return JsonContent(<somedata>);
    }
}

简单的基类控制器

public class JsonController : BaseController
{
    protected ContentResult JsonContent(Object data)
    {
        return new ContentResult
        {
            ContentType = "application/json",
             Content = JsonConvert.SerializeObject(data, new JsonSerializerSettings { 
              ContractResolver = new CamelCasePropertyNamesContractResolver() }),
            ContentEncoding = Encoding.UTF8
        };
    }
}

在ASP.NET Core MVC中。

    public IActionResult Foo()
    {
        var data = GetData();

        var settings = new JsonSerializerSettings 
        { 
            ContractResolver = new CamelCasePropertyNamesContractResolver() 
        });

        return Json(data, settings);
    }

以下是通过序列化对象数组返回json字符串（cameCase）的操作方法。

public string GetSerializedCourseVms()
    {
        var courses = new[]
        {
            new CourseVm{Number = "CREA101", Name = "Care of Magical Creatures", Instructor ="Rubeus Hagrid"},
            new CourseVm{Number = "DARK502", Name = "Defence against dark arts", Instructor ="Severus Snape"},
            new CourseVm{Number = "TRAN201", Name = "Transfiguration", Instructor ="Minerva McGonal"}
        };
        var camelCaseFormatter = new JsonSerializerSettings();
        camelCaseFormatter.ContractResolver = new CamelCasePropertyNamesContractResolver();
        return JsonConvert.SerializeObject(courses, camelCaseFormatter);
    }

请注意，作为第二个参数传递的JsonSerializerSettings实例。这就是使camelCase发生的原因。

我确实这样：

public static class JsonExtension
{
    public static string ToJson(this object value)
    {
        var settings = new JsonSerializerSettings
        {
            ContractResolver = new CamelCasePropertyNamesContractResolver(),
            NullValueHandling = NullValueHandling.Ignore,
            ReferenceLoopHandling = ReferenceLoopHandling.Serialize
        };
        return JsonConvert.SerializeObject(value, settings);
    }
}

这是MVC核心中的一种简单扩展方法，它将为您项目中的每个对象提供ToJson（）功能，在我看来，在MVC项目中，大多数对象都应该具有成为json的能力，这当然取决于:)

您必须在文件“ Startup.cs”中设置设置

您还必须在JsonConvert的默认值中定义它，这是在以后要直接使用该库序列化对象的情况下使用的。

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2)
            .AddJsonOptions(options => {
                options.SerializerSettings.NullValueHandling = NullValueHandling.Ignore;
                options.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
            });
        JsonConvert.DefaultSettings = () => new JsonSerializerSettings
        {
            NullValueHandling = NullValueHandling.Ignore,
            ContractResolver = new CamelCasePropertyNamesContractResolver()
        };
    }

如果要在.net核心Web api或IHttpAction结果中返回ActionResult，则只需将模型包装在Ok（）方法中，该方法将与前端的大小写匹配并为您序列化。无需使用JsonConvert。:)