C#中 如何处理 JSON中的特殊字符

 public static String StringToJson(String s)
        {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < s.Length; i++)
            {
                char c = s[i];
                switch (c)
                {
                    case ‘\"‘:
                        sb.Append("\\\"");
                        break;
                    case ‘\\‘:
                        sb.Append("\\\\");
                        break;
                    case ‘/‘:
                        sb.Append("\\/");
                        break;
                    case ‘\b‘:
                        sb.Append("\\b");
                        break;
                    case ‘\f‘:
                        sb.Append("\\f");
                        break;
                    case ‘\n‘:
                        sb.Append("\\n");
                        break;
                    case ‘\r‘:
                        sb.Append("\\r");
                        break;
                    case ‘\t‘:
                        sb.Append("\\t");
                        break;
                    default:
                        sb.Append(c);
                        break;
                }
            }
            return sb.ToString();
        }