无法创建抽象类或接口“Newtonsoft.Json.JsonWriter”的实例

网上大多都是JsonWriter writer = new JsonWriter(sw) 这样VS报无法创建抽象类或接口“Newtonsoft.Json.JsonWriter”的实例

版本Newtonsoft4.5改为以下

  StringWriter sw = new StringWriter();
            using (JsonWriter writer = new JsonTextWriter(sw))
            {
                writer.Formatting = Formatting.Indented;
                writer.WriteStartObject();
                writer.WritePropertyName("myparams");
                writer.WriteStartObject();
                writer.WritePropertyName("shopid");
                writer.WriteValue("cashop");
                writer.WritePropertyName("version");
                writer.WriteValue("2.0");
                writer.WritePropertyName("format");
                writer.WriteValue("json");
                writer.WritePropertyName("appkey");
                writer.WriteValue("123456");
                writer.WritePropertyName("secretkey");
                writer.WriteValue("1f7c43e50645e814c0d8c47e3a621243");
                writer.WritePropertyName("sessionkey");
                writer.WriteValue("61019102a237e5d5ea182253c4f44578fb182b212b45837512998550");
                writer.WritePropertyName("apiname");
                writer.WriteValue("Get.Data");
                writer.WritePropertyName("apiparam");
                writer.WriteStartObject();
                writer.WritePropertyName("date");
                writer.WriteValue("time");
                writer.WriteEndObject();
                writer.WriteEndObject();
                writer.WriteEndObject();

                writer.Flush();
                sw.Close();
            }

            using (JsonReader reader = new JsonTextReader(new StringReader(sw.GetStringBuilder().ToString())))
            {
                while (reader.Read())
                {
                    if (reader.Value != null)
                    {
                        String jsonVale = reader.Value + "//" + reader.TokenType + "//" + reader.ValueType;
                    }
                }
            }

JsonWriter输出格式为：

{
    myparams: {
        "shopid": "cashop",
        "version": "2.0",
        "format": "json",
        "appkey": "123456",
        "secretkey": "1f7c43e50645e814c0d8c47e3a621243",
        "sessionkey": "61019102a237e5d5ea182253c4f44578fb182b212b45837512998550",
        "apiname": "Get.Sysuser",
        "apiparam": {
             date:time    
        }
    }
}