Suppress properties with null value on ASP.NET Web API

Question

I\'ve created an ASP.Net WEB API Project that will be used by a mobile application. I need the response json to omit null properties instead of return them as property

Answer 1

If you are using vnext, in vnext web api projects, add this code to startup.cs file.

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc().Configure<MvcOptions>(options =>
        {
            int position = options.OutputFormatters.FindIndex(f =>  f.Instance is JsonOutputFormatter);

            var settings = new JsonSerializerSettings()
            {
                NullValueHandling = NullValueHandling.Ignore
            };

            var formatter = new JsonOutputFormatter();
            formatter.SerializerSettings = settings;

            options.OutputFormatters.Insert(position, formatter);
        });

    }

Answer 2

For ASP.NET Core 3.0, the ConfigureServices() method in Startup.cs code should contain:

services.AddControllers()
    .AddJsonOptions(options =>
    {
        options.JsonSerializerOptions.IgnoreNullValues = true;
    });

Answer 3

You can also use [DataContract] and [DataMember(EmitDefaultValue=false)] attributes

Answer 4

In the WebApiConfig:

config.Formatters.JsonFormatter.SerializerSettings = 
                 new JsonSerializerSettings {NullValueHandling = NullValueHandling.Ignore};

Or, if you want more control, you can replace entire formatter:

var jsonformatter = new JsonMediaTypeFormatter
{
    SerializerSettings =
    {
        NullValueHandling = NullValueHandling.Ignore
    }
};

config.Formatters.RemoveAt(0);
config.Formatters.Insert(0, jsonformatter);

Answer 5

I ended up with this piece of code in the startup.cs file using ASP.NET5 1.0.0-beta7

services.AddMvc().AddJsonOptions(options =>
{
    options.SerializerSettings.NullValueHandling = NullValueHandling.Ignore;
});