How to escape JSON string?

In .Net Core 3+ and .Net 5+:

string escapedJsonString = JsonEncodedText.Encode(jsonString);

I nice one-liner, used JsonConvert as others have but added substring to remove the added quotes and backslash.

 var escapedJsonString = JsonConvert.ToString(JsonString).Substring(1, JsonString.Length - 2);

There's a Json library at Codeplex

I chose to use System.Web.Script.Serialization.JavaScriptSerializer.

I have a small static helper class defined as follows:

internal static partial class Serialization
{
    static JavaScriptSerializer serializer;
    
    static Serialization()
    {
        serializer = new JavaScriptSerializer();
        serializer.MaxJsonLength = Int32.MaxValue;
    }
    public static string ToJSON<T>(T obj)
    {
        return serializer.Serialize(obj);
    }
    public static T FromJSON<T>(string data)
    {
        if (Common.IsEmpty(data))
            return default(T);
        else
            return serializer.Deserialize<T>(data);
    }
}

To serialize anything I just call Serialization.ToJSON(itemToSerialize)

To deserialize I just call Serialization.FromJSON<T>(jsonValueOfTypeT)