使用 JSON.Net 的 Web API 的骆驼大小写问题

Question

我想使用 Web API 返回骆驼大小写的 JSON 数据。我继承了一个乱七八糟的项目，它使用了前任程序员目前喜欢使用的任何外壳（说真的！所有大写字母、小写字母、pascal-casing 和 camel-casing - 随你选！），所以我不能使用这个技巧把它放在 WebApiConfig.cs 文件中，因为它会破坏现有的 API 调用：

// Enforce camel-casing for the JSON objects being returned from API calls.
config.Formatters.OfType<JsonMediaTypeFormatter>().First().SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();

所以我使用了一个使用 JSON.Net 序列化程序的自定义类。代码如下：

using System.Web.Http;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;

public class JsonNetApiController : ApiController
{
    public string SerializeToJson(object objectToSerialize)
    {
        var settings = new JsonSerializerSettings
        {
            ContractResolver = new CamelCasePropertyNamesContractResolver()
        };

        if (objectToSerialize != null)
        {
            return JsonConvert.SerializeObject(objectToSerialize, Formatting.None, settings);
        }

        return string.Empty;
    }
}

问题是返回的原始数据是这样的：

"[{\"average\":54,\"group\":\"P\",\"id\":1,\"name\":\"Accounting\"}]"

如您所见，反斜杠把事情搞砸了。这是我使用自定义类调用的方式：

public class Test
{
    public double Average { get; set; }
    public string Group { get; set; }
    public int Id { get; set; }
    public string Name { get; set; }
}

public class SomeController : JsonNetApiController
{
    public HttpResponseMessage Get()

    var responseMessage = new List<Test>
    {
        new Test
        {
            Id = 1,
            Name = "Accounting",
            Average = 54,
            Group = "P",
        }
    };

    return Request.CreateResponse(HttpStatusCode.OK, SerializeToJson(responseMessage), JsonMediaTypeFormatter.DefaultMediaType);

}

我可以做些什么来摆脱反斜杠？是否有其他方法可以强制执行骆驼套管？

Answer 1

感谢所有对其他 Stackoverflow 页面的引用，我将发布三个解决方案，以便其他有类似问题的人可以选择代码。第一个代码示例是我在查看其他人在做什么之后创建的。最后两个来自其他 Stackoverflow 用户。我希望这对其他人有帮助！

// Solution #1 - This is my solution. It updates the JsonMediaTypeFormatter whenever a response is sent to the API call.
// If you ever need to keep the controller methods untouched, this could be a solution for you.
using System;
using System.Net;
using System.Net.Http;
using System.Net.Http.Formatting;
using System.Web.Http;
using Newtonsoft.Json.Serialization;

public class CamelCasedApiController : ApiController
{
    public HttpResponseMessage CreateResponse(object responseMessageContent)
    {
        try
        {
            var httpResponseMessage = Request.CreateResponse(HttpStatusCode.OK, responseMessageContent, JsonMediaTypeFormatter.DefaultMediaType);
            var objectContent = httpResponseMessage.Content as ObjectContent;

            if (objectContent != null)
            {
                var jsonMediaTypeFormatter = new JsonMediaTypeFormatter
                {
                    SerializerSettings =
                    {
                        ContractResolver = new CamelCasePropertyNamesContractResolver()
                    }
                };

                httpResponseMessage.Content = new ObjectContent(objectContent.ObjectType, objectContent.Value, jsonMediaTypeFormatter);
            }

            return httpResponseMessage;
        }
        catch (Exception exception)
        {
            return Request.CreateResponse(HttpStatusCode.InternalServerError, exception.Message);
        }
    }
}

第二种解决方案使用属性来装饰 API 控制器方法。

// http://stackoverflow.com/questions/14528779/use-camel-case-serialization-only-for-specific-actions
// This code allows the controller method to be decorated to use camel-casing. If you can modify the controller methods, use this approach.
using System.Net.Http;
using System.Net.Http.Formatting;
using System.Web.Http.Filters;
using Newtonsoft.Json.Serialization;

public class CamelCasedApiMethodAttribute : ActionFilterAttribute
{
    private static JsonMediaTypeFormatter _camelCasingFormatter = new JsonMediaTypeFormatter();

    static CamelCasedApiMethodAttribute()
    {
        _camelCasingFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
    }

    public override void OnActionExecuted(HttpActionExecutedContext httpActionExecutedContext)
    {
        var objectContent = httpActionExecutedContext.Response.Content as ObjectContent;
        if (objectContent != null)
        {
            if (objectContent.Formatter is JsonMediaTypeFormatter)
            {
                httpActionExecutedContext.Response.Content = new ObjectContent(objectContent.ObjectType, objectContent.Value, _camelCasingFormatter);
            }
        }
    }
}

// Here is an example of how to use it.
[CamelCasedApiMethod]
public HttpResponseMessage Get()
{
    ...
}

最后一种解决方案是使用一个属性来装饰整个 API 控制器。

// http://stackoverflow.com/questions/19956838/force-camalcase-on-asp-net-webapi-per-controller
// This code allows the entire controller to be decorated to use camel-casing. If you can modify the entire controller, use this approach.
using System;
using System.Linq;
using System.Net.Http.Formatting;
using System.Web.Http.Controllers;
using Newtonsoft.Json.Serialization;

public class CamelCasedApiControllerAttribute : Attribute, IControllerConfiguration
{
    public void Initialize(HttpControllerSettings httpControllerSettings, HttpControllerDescriptor httpControllerDescriptor)
    {
        var jsonMediaTypeFormatter = httpControllerSettings.Formatters.OfType<JsonMediaTypeFormatter>().Single();
        httpControllerSettings.Formatters.Remove(jsonMediaTypeFormatter);

        jsonMediaTypeFormatter = new JsonMediaTypeFormatter
        {
            SerializerSettings =
            {
                ContractResolver = new CamelCasePropertyNamesContractResolver()
            }
        };

        httpControllerSettings.Formatters.Add(jsonMediaTypeFormatter);
    }
}

// Here is an example of how to use it.
[CamelCasedApiController]
public class SomeController : ApiController
{
    ...
}

Answer 2

如果你想全局设置它，你可以从 HttpConfiguration 中删除当前的 Json 格式化程序，并用你自己的替换它。

public static void Register(HttpConfiguration config)
{
    config.Formatters.Remove(config.Formatters.JsonFormatter);

    var serializer = new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() };
    var formatter = new JsonMediaTypeFormatter { Indent = true, SerializerSettings =  serializer };
    config.Formatters.Add(formatter);
}

Answer 3

评论https://stackoverflow.com/a/26506573/887092适用于某些情况，但不适用于其他情况

var jsonFormatter = GlobalConfiguration.Configuration.Formatters.JsonFormatter;

这种方式适用于其他情况

var jsonFormatter = config.Formatters.OfType<JsonMediaTypeFormatter>().First();

因此，使用以下内容覆盖所有基础：

    private void ConfigureWebApi(HttpConfiguration config)
    {
        //..

        foreach (var jsonFormatter in config.Formatters.OfType<JsonMediaTypeFormatter>())
        {
            jsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
        }

        var singlejsonFormatter = GlobalConfiguration.Configuration.Formatters.JsonFormatter;
        singlejsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();

    }