Web API 2: 如何 return JSON with camelCased 属性 names, on objects and their sub-objects

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更新

谢谢大家的回答。我在一个新项目上，看起来我终于弄清楚了这个问题：看起来实际上是以下代码造成的：

public static HttpResponseMessage GetHttpSuccessResponse(object response, HttpStatusCode code = HttpStatusCode.OK)
{
    return new HttpResponseMessage()
    {
        StatusCode = code,
        Content = response != null ? new JsonContent(response) : null
    };
}

别处...

public JsonContent(object obj)
{
    var encoded = JsonConvert.SerializeObject(obj, Newtonsoft.Json.Formatting.None, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore } );
    _value = JObject.Parse(encoded);

    Headers.ContentType = new MediaTypeHeaderValue("application/json");
}

我忽略了看起来无害的 JsonContent，假设它是 WebAPI 但不是。

这无处不在...我可以第一个说吗？或者也许应该是 "Why are they doing this?"

原问题如下

有人会认为这将是一个简单的配置设置，但我已经想了太久了。

我看了各种解决方案和答案：

https://gist.github.com/rdingwall/2012642

似乎不适用于最新的 WebAPI 版本...

以下似乎不起作用 - 属性名称仍然是 PascalCased。

var json = GlobalConfiguration.Configuration.Formatters.JsonFormatter;

json.UseDataContractJsonSerializer = true;
json.SerializerSettings.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore;

json.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();

Mayank 在这里的回答：CamelCase JSON WebAPI Sub-Objects (Nested objects, child objects) 似乎是一个不令人满意但可行的答案，直到我意识到这些属性必须添加到生成的代码中，因为我们正在使用 linq2sql...

有什么方法可以自动执行此操作？这个 'nasty' 困扰我很久了。

Answer 1

原来是

return Json(result);

是罪魁祸首，导致序列化过程忽略驼峰式设置。还有那个

return Request.CreateResponse(HttpStatusCode.OK, result, Request.GetConfiguration());

是我要找的机器人。

还有

json.UseDataContractJsonSerializer = true;

在工作中放了一把扳手，结果发现这不是我要找的机器人。

Answer 2

把它们放在一起你会得到...

protected void Application_Start()
{
    HttpConfiguration config = GlobalConfiguration.Configuration;
    config.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
    config.Formatters.JsonFormatter.UseDataContractJsonSerializer = false;
}

Answer 3

这对我有用：

internal static class ViewHelpers
{
    public static JsonSerializerSettings CamelCase
    {
        get
        {
            return new JsonSerializerSettings {
                ContractResolver = new CamelCasePropertyNamesContractResolver()
            };
        }
    }
}

然后：

[HttpGet]
[Route("api/campaign/list")]
public IHttpActionResult ListExistingCampaigns()
{
    var domainResults = _campaignService.ListExistingCampaigns();
    return Json(domainResults, ViewHelpers.CamelCase);
}

class CamelCasePropertyNamesContractResolver 来自 Json.NET 库中的 Newtonsoft.Json.dll。

Answer 4

以上所有答案都不适用于 Owin Hosting 和 Ninject。以下是对我有用的方法：

public partial class Startup
{
    public void Configuration(IAppBuilder app)
    {
        // Get the ninject kernel from our IoC.
        var kernel = IoC.GetKernel();

        var config = new HttpConfiguration();

        // More config settings and OWIN middleware goes here.

        // Configure camel case json results.
        ConfigureCamelCase(config);

        // Use ninject middleware.
        app.UseNinjectMiddleware(() => kernel);

        // Use ninject web api.
        app.UseNinjectWebApi(config);
    }

    /// <summary>
    /// Configure all JSON responses to have camel case property names.
    /// </summary>
    private void ConfigureCamelCase(HttpConfiguration config)
    {
        var jsonFormatter = config.Formatters.JsonFormatter;
        // This next line is not required for it to work, but here for completeness - ignore data contracts.
        jsonFormatter.UseDataContractJsonSerializer = false;
        var settings = jsonFormatter.SerializerSettings;
#if DEBUG
        // Pretty json for developers.
        settings.Formatting = Formatting.Indented;
#else
        settings.Formatting = Formatting.None;
#endif
        settings.ContractResolver = new CamelCasePropertyNamesContractResolver();
    }
}

主要区别在于：new HttpConfiguration() 而不是 GlobalConfiguration.Configuration。

Answer 5

这是一个晦涩的例子，当路由属性不匹配 GET url 但 GET url 匹配方法名称时，jsonserializer 驼峰指令将被忽略，例如

http://website/api/geo/geodata

//uppercase fail cakes
[HttpGet]
[Route("countries")]
public async Task<GeoData> GeoData()
{
    return await geoService.GetGeoData();
}

//lowercase nomnomnom cakes
[HttpGet]
[Route("geodata")]
public async Task<GeoData> GeoData()
{
    return await geoService.GetGeoData();
}

Answer 6

WebApiConfig 代码：

    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            // Web API configuration and services
    
            // Web API routes
            config.MapHttpAttributeRoutes();
    
            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
    
            //This line sets json serializer's ContractResolver to CamelCasePropertyNamesContractResolver, 
            //  so API will return json using camel case
            config.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
    
        }
    }

确保您的 API 操作方法 returns 数据符合以下方式，并且您已安装最新版本的 Json.Net/Newtonsoft.Json：

    [HttpGet]
    public HttpResponseMessage List()
    {
        try
        {
            var result = /*write code to fetch your result - type can be anything*/;
            return Request.CreateResponse(HttpStatusCode.OK, result);
        }
        catch (Exception ex)
        {
            return Request.CreateResponse(HttpStatusCode.InternalServerError, ex.Message);
        }
    }

Answer 7

我已经通过以下方式解决了

[AllowAnonymous]
[HttpGet()]
public HttpResponseMessage GetAllItems(int moduleId)
{
    HttpConfiguration config = new HttpConfiguration();
            config.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
            config.Formatters.JsonFormatter.UseDataContractJsonSerializer = false;

            try
            {
                List<ItemInfo> itemList = GetItemsFromDatabase(moduleId);
                return Request.CreateResponse(HttpStatusCode.OK, itemList, config);
            }
            catch (System.Exception ex)
            {
                return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, ex.Message);
            }
}

Answer 8

我将 WebApi 与 Breeze 一起使用，我运行在尝试对 breeze 控制器执行 non-breeze 操作时遇到同样的问题。我尝试使用 apprach Request.GetConfiguration 但结果相同。因此，当我访问 Request.GetConfiguration 返回的 object 时，我意识到请求使用的序列化程序是 breeze-server 用来使其变得神奇的序列化程序。无论如何，我通过创建不同的 HttpConfiguration:

解决了我的问题

public static HttpConfiguration BreezeControllerCamelCase
        {
            get
            {
                var config = new HttpConfiguration();
                var jsonSerializerSettings = config.Formatters.JsonFormatter.SerializerSettings;
                jsonSerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
                jsonSerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
                config.Formatters.JsonFormatter.UseDataContractJsonSerializer = false;

                return config;
            }
        }

并将其作为参数传递给 Request.CreateResponse，如下所示：

return this.Request.CreateResponse(HttpStatusCode.OK, result, WebApiHelper.BreezeControllerCamelCase);

Answer 9

在您的 Owin Startup 中添加此行...

 public class Startup
{
    public void Configuration(IAppBuilder app)
    {
        var webApiConfiguration = ConfigureWebApi();            
        app.UseWebApi(webApiConfiguration);
    }

    private HttpConfiguration ConfigureWebApi()
    {
        var config = new HttpConfiguration();

        // ADD THIS LINE HERE AND DONE
        config.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver(); 

        config.MapHttpAttributeRoutes();
        return config;
    }
}

Web API 2: 如何 return JSON with camelCased 属性 names, on objects and their sub-objects

Web API 2: how to return JSON with camelCased property names, on objects and their sub-objects

c#

.net

asp.net-web-api

json.net

asp.net-web-api2