利用Newtonsoft.Json实现Json序列化与反序列化

在项目中用到了Newtonsoft.Json来实现序列化和反序列化，在这里写下实现代码。

1、创建类用于排除不序列化的属性

public class ExcludePropertiesContractResolver : DefaultContractResolver
    {
        IEnumerable<string> lstExclude;

        public ExcludePropertiesContractResolver(IEnumerable<string> excludedProperties)
        {
            lstExclude = excludedProperties;
        }

        protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
        {
            return base.CreateProperties(type, memberSerialization).ToList().FindAll(p => !lstExclude.Contains(p.PropertyName));
        }
    }

2、序列化方法

以下分别是将对象、DataTable、集合序列化为Json字符串的方法：

        /// <summary>
        /// T对象转换成json字符串
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obj"></param>
        /// <returns></returns>
        public static string GetJsonString<T>(T obj, params string[] ignoreFields)
        {
            IsoDateTimeConverter iso = new IsoDateTimeConverter();
            iso.DateTimeFormat = "yyyy-MM-ddTHH:mm:ss";
            iso.DateTimeStyles = System.Globalization.DateTimeStyles.AssumeLocal;
            string jsonStr = string.Empty;
            JsonSerializerSettings js = new JsonSerializerSettings();
            if (ignoreFields != null && ignoreFields.Length > 0)
            {
                List<string> ignoreList = ignoreFields.ToList();
                js.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
                js.ContractResolver = new ExcludePropertiesContractResolver(ignoreList);
            }
            js.Converters.Add(iso);
            jsonStr = JsonConvert.SerializeObject(obj, Formatting.Indented, js);
            return jsonStr;
        }

        /// <summary>
        /// DataTable对象转换成json字符串
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public static string GetJsonString(DataTable dt, params string[] ignoreFields)
        {
            IsoDateTimeConverter iso = new IsoDateTimeConverter();
            iso.DateTimeFormat = "yyyy-MM-ddTHH:mm:ss";
            iso.DateTimeStyles = System.Globalization.DateTimeStyles.AssumeLocal;
            string jsonStr = string.Empty;
            JsonSerializerSettings js = new JsonSerializerSettings();
            if (ignoreFields != null && ignoreFields.Length > 0)
            {
                List<string> ignoreList = ignoreFields.ToList();
                js.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
                js.ContractResolver = new ExcludePropertiesContractResolver(ignoreList);
            }
            js.Converters.Add(new DataTableConverter());
            js.Converters.Add(iso);
            jsonStr = JsonConvert.SerializeObject(dt, Formatting.Indented,js);
            return jsonStr;
        }

        /// <summary>
        /// List对象转换成json字符串
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public static string GetJsonString<T>(List<T> list, params string[] ignoreFields)
        {
            IsoDateTimeConverter iso = new IsoDateTimeConverter();
            iso.DateTimeFormat = "yyyy-MM-ddTHH:mm:ss";
            iso.DateTimeStyles = System.Globalization.DateTimeStyles.AssumeLocal;
            string jsonStr = string.Empty;
            JsonSerializerSettings js = new JsonSerializerSettings();
            if (ignoreFields != null && ignoreFields.Length > 0)
            {
                List<string> ignoreList = ignoreFields.ToList();
                js.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
                js.ContractResolver = new ExcludePropertiesContractResolver(ignoreList);
            }
            js.Converters.Add(iso);
            jsonStr = JsonConvert.SerializeObject(list, Formatting.Indented, js);
            return jsonStr;
        }

3、反序列化

以下是将Json字符串反序列化为对象、集合的方法。

        /// <summary>
        /// json字符串转换成T对象
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="jsonStr"></param>
        /// <returns></returns>
        public static T GetObjectByJsonString<T>(string jsonStr)
        {
            T obj = JsonConvert.DeserializeObject<T>(jsonStr);
            return obj;
        }

        /// <summary>
        /// json字符串转换成List对象
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="jsonStr"></param>
        /// <returns></returns>
        public static List<T> GetListByJsonString<T>(string jsonStr)
        {
            List<T> list = JsonConvert.DeserializeObject<List<T>>(jsonStr);
            return list;
        }