I have an endpoint that I am migrating. The current format of the JSON being sent to the endpoint is:

{
    "settings":{
        "Target":30,
        "UserId":12345
    }
}

Currently with a method signature like this...

public string GetTarget(Settings settings);

It appears that the Web API deserializer is looking for the JSON to be formatted as follows (with no top level variable name):

{
    "Target":30,
    "UserId":12345
}

I have a legacy app that sends the JSON with the "settings" variable name and I cannot update it to send the unnested format. Is there any way to have Web API target the nested properties within "settings"?

CodePudding user response：

You can try to use custom model binding.Here is a demo:

Settings:

public class Settings {
        public int Target { get; set; }
        public int UserId { get; set; }

    }

action:

public string GetTarget([ModelBinder(BinderType = typeof(CustomBinder))] Settings settings)

CustomBinder:

public class CustomBinder : IModelBinder
    {
        public Task BindModelAsync(ModelBindingContext bindingContext)
        {
            if (bindingContext == null)
            {
                throw new ArgumentNullException(nameof(bindingContext));
            }
            var model = new Settings();
            using (var reader = new StreamReader(bindingContext.HttpContext.Request.Body))
            {
                var body = reader.ReadToEndAsync();

                var mydata = JsonConvert.DeserializeObject<JObject>(body.Result);
                model = JsonConvert.DeserializeObject<Settings>(mydata["settings"].ToString());
                

            }

            bindingContext.Result = ModelBindingResult.Success(model);
            return Task.CompletedTask;
        }
    }

result:

CodePudding user response：

try this,it was tested using VS and Postman. It doesn't need any custom converter

using Newtonsoft.Json.Linq;
....

public string GetTarget([FromBody] JObject settingsObj)
{
Settings settings;
     
if (settingsObj["settings"] != null)  settings = settingsObj["settings"].ToObject<Settings>();
else settings = settingsObj.ToObject<Settings>();
    ......
}

public class Settings
{
    public int Target { get; set; }
    public int UserId { get; set; }
}