.net 4中使用 dynamic,将json字符串转成对象的 万能方法。
在.net 4中增加了对弱类型的支持。为和弱类型的对象进行数据交换提供了方法。我们常常会遇到将json字符串转成对象的情景,虽然可以使用
JavaScriptSerializer 或者
但是仍然需要些个对应的实体类,非常的麻烦。我在网上查资料,找到另外的实现方法:DataContractJsonSerializer
使用:
string json = "[{\"name\":\"zhang3\"},{\"name\":\"zhang4\"}]"; var j = new JsonParser().FromJson(json); //j是个 object[] int len = j.Length; var obj1 = j[0]; var name = j[1].name;
注意这里用到 dynamic 类型。在这里,弱类型的威力凸显出来了。
我们看看具体的实现类:
/// <summary> /// json转换 /// </summary> public class JsonParser { /// <summary> /// 从json字符串到对象。 /// </summary> /// <param name="jsonStr"></param> /// <returns></returns> public dynamic FromJson(string jsonStr) { JavaScriptSerializer jss = new JavaScriptSerializer(); jss.RegisterConverters(new JavaScriptConverter[] { new DynamicJsonConverter() }); dynamic glossaryEntry = jss.Deserialize(jsonStr, typeof(object)) as dynamic; return glossaryEntry; } } public class DynamicJsonConverter : JavaScriptConverter { public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer) { if (dictionary == null) throw new ArgumentNullException("dictionary"); if (type == typeof(object)) { return new DynamicJsonObject(dictionary); } return null; } public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer) { throw new NotImplementedException(); } public override IEnumerable<Type> SupportedTypes { get { return new ReadOnlyCollection<Type>(new List<Type>(new Type[] { typeof(object) })); } } } public class DynamicJsonObject : DynamicObject { private IDictionary<string, object> Dictionary { get; set; } public DynamicJsonObject(IDictionary<string, object> dictionary) { this.Dictionary = dictionary; } public override bool TryGetMember(GetMemberBinder binder, out object result) { result = this.Dictionary[binder.Name]; if (result is IDictionary<string, object>) { result = new DynamicJsonObject(result as IDictionary<string, object>); } else if (result is ArrayList && (result as ArrayList) is IDictionary<string, object>) { result = new List<DynamicJsonObject>((result as ArrayList).ToArray().Select(x => new DynamicJsonObject(x as IDictionary<string, object>))); } else if (result is ArrayList) { result = new List<object>((result as ArrayList).ToArray()); } return this.Dictionary.ContainsKey(binder.Name); } }
参考:
http://www.codeproject.com/Articles/349646/Dynamic-JSON-parser
http://msdn.microsoft.com/zh-cn/library/dd264736.aspx
http://www.oschina.net/question/89964_45078
http://stackoverflow.com/questions/6201529/turn-c-sharp-object-into-a-json-string-in-net-4