How to turn off or handle camelCasing in JSON response ASP.NET Core?

Question

I\'m running through a WintellectNOW course on ASP.NET Core/Web API/Angular 2. I have the API portion implemented, but for whatever reason, the JSON that is being returned h

Answer 1

In Asp.Net Core 3.0 some things have changed. For camelCase do nothing that is out of the box. For PascalCase or another set style use.

services.AddMvc(setupAction=> {
            setupAction.EnableEndpointRouting = false;
        }).AddJsonOptions(jsonOptions =>
        {
            jsonOptions.JsonSerializerOptions.PropertyNamingPolicy = null;
        })
        .SetCompatibilityVersion(CompatibilityVersion.Version_3_0);

In Startup.cs ConfigureServices section

Answer 2

Another solution in Asp.Net.Core 2.2 as following:

services.AddMvc()
.AddJsonOptions(jsonOptions => jsonOptions.UseMemberCasing())
.SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

Answer 3

In ASP.NET Core <3.0, JSON properties are camelCased by default (per this announcement).

You can disable this by replacing

services.AddMvc();

with

services
    .AddMvc()
    .AddJsonOptions(opt => opt.SerializerSettings.ContractResolver
        = new DefaultContractResolver());

in your Startup.cs file. You'll have to add using Newtonsoft.Json.Serialization; to the top of the file.

With the DefaultContractResolver in place, the property names will be represented verbatim in the JSON output. No need for DataMember attributes.

Answer 4

I am using the following solution because

• a) I prefer using the .Net Core built in System.Text.Json serializer and
• b) I do not want to rely on the not documented internal behaviour of jsonOptions.JsonSerializerOptions.PropertyNamingPolicy = null;.

.

services.AddControllers()
    .AddJsonOptions(options =>
    {
        options.JsonSerializerOptions.PropertyNamingPolicy = new MyTransparentJsonNamingPolicy();
    });

where:

public class MyTransparentJsonNamingPolicy : JsonNamingPolicy
{
    // You can came up any custom transformation here, so instead just transparently
    // pass through the original C# class property name, it is possible to explicit
    // convert to PascalCase, etc:
    public override string ConvertName(string name)
    {
        return name;
    }
}

Answer 5

You have to change the DefaultContractResolver which uses camelCase by default. Just set the NamingStatergy as null.

This should be done in the StartUp.ConfirgureService as follows.

  public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc()
            .AddMvcOptions(o => o.OutputFormatters.Add(
                new XmlDataContractSerializerOutputFormatter()));

            .AddJsonOptions(o => {
                if (o.SerializerSettings.ContractResolver != null)
                {
                    var castedResolver = o.SerializerSettings.ContractResolver
                        as DefaultContractResolver;
                    castedResolver.NamingStrategy = null;
                }
            });
    }

Option 2

Use JSonProperty as follows.

public class Hat
{
    [JsonProperty("id")]
    public int Id { get; set; }
    [JsonProperty("name")]
    public string Name { get; set; }
    [JsonProperty("color")]
    public string Color { get; set; }
    [JsonProperty("count")]
    public int Count { get; set; }
}

Answer 6

For Asp.Net Core 3.1 using the NewtonSoft.Json

services.AddControllers()
        .AddNewtonsoftJson(options =>
        {
            options.UseMemberCasing();
        });