Assign Json to a string without serilization in c#

I have a JSON string

{
  "F1":
  { 
    "BF1":"BV1",
    "BF2":"BV2"
  },
  "F2":"BF1"
}

and I wish to assign it to an object of this type

public class MyType
{
   public string F1 {get;set;} 
   public string F2 {get;set;}
}

in other words, I need to convert JSON to an object, but the inner object is to be assigned as a JSON string

the simpliest way is

	var jObj = JObject.Parse(json);

	MyType myType = new MyType
	{
		F1 = jObj["F1"].ToString(),
		F2 = jObj["F2"].ToString()
	};

or if you don't want indented formating

MyType myType = new MyType
	{
		F1 = JsonConvert.SerializeObject(jObj["F1"]),
		F2 = (string) jObj["F2"];
	};

of if you like a hard way

MyType myType = JsonConvert.DeserializeObject<MyType>(json,new MyTypeJsonConverter());

public class MyTypeJsonConverter : JsonConverter<MyType>
{
	public override MyType ReadJson(JsonReader reader, Type objectType, MyType existingValue, bool hasExistingValue, JsonSerializer serializer)
	{
		var jObj = JObject.Load(reader);

		return new MyType
		{
			F1 = JsonConvert.SerializeObject(jObj["F1"]),
			F2 = (string)jObj["F2"]
		};
	}

    // or maybe this 
    // public override bool CanWrite => false;

	public override void WriteJson(JsonWriter writer, MyType value, JsonSerializer serializer)
	{
		var val = new
		{
			F1 = JObject.Parse(value.F1),
			F2 = value.F2
		};
		
		writer.WriteRaw(JsonConvert.SerializeObject(val, Newtonsoft.Json.Formatting.Indented));
	}
	
}

or if you have many properties that should deserialize common way

MyType myType = JsonConvert.DeserializeObject<MyType>(json);

public class MyType
{ 
   [JsonConverter(typeof(MyTypePropertyJsonConverter))]
	public string F1 { get; set; }
	
	public string F2 { get; set; }
}

public class MyTypePropertyJsonConverter : JsonConverter<string>
{
	public override string ReadJson(JsonReader reader, Type objectType, string existingValue, bool hasExistingValue, JsonSerializer serializer)
	{
		return JsonConvert.SerializeObject(JToken.Load(reader));
	}

	public override void WriteJson(JsonWriter writer, string value, JsonSerializer serializer)
	{
		writer.WriteRawValue(value);
	}
}

Though the answer posted by @serge looks best to me. But I spent some time to resolve your issue and I ended up with the below code:

dynamic jsonElement = JsonSerializer.Deserialize<dynamic>(json);
MyType myType = new MyType();
myType.F1 = jsonElement.GetProperty("F1").ToString();
myType.F2 = jsonElement.GetProperty("F2").ToString();		
Console.WriteLine(myType.F1 + ", " + myType.F2);

I hope it may help you some way.