ASP.NET Core Json object is strange formatted with \u0022

Question

I am planning to do a JSON Response from an ASP.NET Core Controller but it is not as simple as I thought.

A simple string like {"ConfigValue":"192.168.1.125:1880"} should be serialized to a JsonObject and this object shall be part of the JSON Response.

But what the return Json(str) response is something like

{\u0022ConfigValue\u0022:\u0022192.168.1.125:1880\u0022}

I have no clue how to get rid of \u0022

public class commonController : Microsoft.AspNetCore.Mvc.Controller
{
    private  IConfiguration config;

    public commonController(IConfiguration configuration)
    {
        config = configuration;
    }
    // GET
    [Route("getConfigEntry/{key?}")]
    public JsonResult getConfigEntry(string? key)
    {
        Dictionary<string, string> dict = new Dictionary<string, string>
        {
            {"ConfigValue", "192.168.1.125:1880"}
        };
        str = JsonConvert.SerializeObject(dict,Formatting.None); //from debugger variable viewer {"ConfigValue":"192.168.1.125:1880"}
        return Json(str); // "{\u0022ConfigValue\u0022:\u0022192.168.1.125:1880\u0022}"
    }
}

Answer 1

You're serializing into JSON twice - first you're serializing the dictionary into a string, then you're serializing that string as a JSON value... which involves escaping quotes.

You should only serialize it once - you don't have to call JsonConvert.SerializeObject at all:

return Json(dict);