是否有方法将JSON内容反序列化为c#动态类型?为了使用DataContractJsonSerializer,最好跳过创建一堆类。
当前回答
我来这里是为了找到。net Core的答案,没有任何第三方或其他参考。如果您将ExpandoObject与标准JsonSerializer类一起使用,那么它工作得很好。下面是一个对我有用的例子:
using System.Text.Json;
using System.Dynamic;
dynamic json = JsonSerializer.Deserialize<ExpandoObject>(jsonText);
Console.WriteLine(json.name);
这段代码输出一个name属性的字符串值,该属性存在于传递给Deserialize方法的JSON文本中。瞧——没有额外的库,什么都没有。只是。net核心。
编辑:有嵌套元素的json的几个级别可能会有问题。适用于单层平面对象。
其他回答
我很喜欢system。web。helpers,
dynamic data = Json.Decode(json);
因为它支持像
var val = data.Members.NumberTen;
or
var val data.Members["10"];
对System.Web.Helpers.DLL的引用真的很疯狂,它甚至不适合控制台和桌面应用程序。下面是我尝试直接从https://github.com/mono/aspnetwebstack/tree/master/src/System.Web.Helpers提取作为独立文件的相同功能 (分享此内容仅供教育之用)
// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Dynamic;
using System.Linq.Expressions;
using System.Runtime.CompilerServices;
using Microsoft.CSharp.RuntimeBinder;
using System.Web.Script.Serialization;
using System.IO;
using System.Collections;
using System.Linq;
using System.Globalization;
namespace System.Web.Helpers
{
public static class Json
{
private static readonly JavaScriptSerializer _serializer = CreateSerializer();
public static string Encode(object value)
{
// Serialize our dynamic array type as an array
DynamicJsonArray jsonArray = value as DynamicJsonArray;
if (jsonArray != null)
{
return _serializer.Serialize((object[])jsonArray);
}
return _serializer.Serialize(value);
}
public static void Write(object value, TextWriter writer)
{
writer.Write(_serializer.Serialize(value));
}
public static dynamic Decode(string value)
{
return WrapObject(_serializer.DeserializeObject(value));
}
public static dynamic Decode(string value, Type targetType)
{
return WrapObject(_serializer.Deserialize(value, targetType));
}
public static T Decode<T>(string value)
{
return _serializer.Deserialize<T>(value);
}
private static JavaScriptSerializer CreateSerializer()
{
JavaScriptSerializer serializer = new JavaScriptSerializer();
serializer.RegisterConverters(new[] { new DynamicJavaScriptConverter() });
return serializer;
}
internal class DynamicJavaScriptConverter : JavaScriptConverter
{
public override IEnumerable<Type> SupportedTypes
{
get
{
yield return typeof(IDynamicMetaObjectProvider);
yield return typeof(DynamicObject);
}
}
public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
{
throw new NotSupportedException();
}
public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
{
Dictionary<string, object> dictionary = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
IEnumerable<string> memberNames = DynamicHelper.GetMemberNames(obj);
foreach (string item in memberNames)
{
dictionary[item] = DynamicHelper.GetMemberValue(obj, item);
}
return dictionary;
}
}
internal static dynamic WrapObject(object value)
{
// The JavaScriptSerializer returns IDictionary<string, object> for objects
// and object[] for arrays, so we wrap those in different dynamic objects
// so we can access the object graph using dynamic
var dictionaryValues = value as IDictionary<string, object>;
if (dictionaryValues != null)
{
return new DynamicJsonObject(dictionaryValues);
}
var arrayValues = value as object[];
if (arrayValues != null)
{
return new DynamicJsonArray(arrayValues);
}
return value;
}
}
// REVIEW: Consider implementing ICustomTypeDescriptor and IDictionary<string, object>
public class DynamicJsonObject : DynamicObject
{
private readonly IDictionary<string, object> _values;
public DynamicJsonObject(IDictionary<string, object> values)
{
Debug.Assert(values != null);
_values = values.ToDictionary(p => p.Key, p => Json.WrapObject(p.Value),
StringComparer.OrdinalIgnoreCase);
}
public override bool TryConvert(ConvertBinder binder, out object result)
{
result = null;
if (binder.Type.IsAssignableFrom(_values.GetType()))
{
result = _values;
}
else
{
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, "HelpersResources.Json_UnableToConvertType", binder.Type));
}
return true;
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
result = GetValue(binder.Name);
return true;
}
public override bool TrySetMember(SetMemberBinder binder, object value)
{
_values[binder.Name] = Json.WrapObject(value);
return true;
}
public override bool TrySetIndex(SetIndexBinder binder, object[] indexes, object value)
{
string key = GetKey(indexes);
if (!String.IsNullOrEmpty(key))
{
_values[key] = Json.WrapObject(value);
}
return true;
}
public override bool TryGetIndex(GetIndexBinder binder, object[] indexes, out object result)
{
string key = GetKey(indexes);
result = null;
if (!String.IsNullOrEmpty(key))
{
result = GetValue(key);
}
return true;
}
private static string GetKey(object[] indexes)
{
if (indexes.Length == 1)
{
return (string)indexes[0];
}
// REVIEW: Should this throw?
return null;
}
public override IEnumerable<string> GetDynamicMemberNames()
{
return _values.Keys;
}
private object GetValue(string name)
{
object result;
if (_values.TryGetValue(name, out result))
{
return result;
}
return null;
}
}
[SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix", Justification = "This class isn't meant to be used directly")]
public class DynamicJsonArray : DynamicObject, IEnumerable<object>
{
private readonly object[] _arrayValues;
public DynamicJsonArray(object[] arrayValues)
{
Debug.Assert(arrayValues != null);
_arrayValues = arrayValues.Select(Json.WrapObject).ToArray();
}
public int Length
{
get { return _arrayValues.Length; }
}
public dynamic this[int index]
{
get { return _arrayValues[index]; }
set { _arrayValues[index] = Json.WrapObject(value); }
}
public override bool TryConvert(ConvertBinder binder, out object result)
{
if (_arrayValues.GetType().IsAssignableFrom(binder.Type))
{
result = _arrayValues;
return true;
}
return base.TryConvert(binder, out result);
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
// Testing for members should never throw. This is important when dealing with
// services that return different json results. Testing for a member shouldn't throw,
// it should just return null (or undefined)
result = null;
return true;
}
public IEnumerator GetEnumerator()
{
return _arrayValues.GetEnumerator();
}
private IEnumerable<object> GetEnumerable()
{
return _arrayValues.AsEnumerable();
}
IEnumerator<object> IEnumerable<object>.GetEnumerator()
{
return GetEnumerable().GetEnumerator();
}
[SuppressMessage("Microsoft.Usage", "CA2225:OperatorOverloadsHaveNamedAlternates", Justification = "This class isn't meant to be used directly")]
public static implicit operator object[](DynamicJsonArray obj)
{
return obj._arrayValues;
}
[SuppressMessage("Microsoft.Usage", "CA2225:OperatorOverloadsHaveNamedAlternates", Justification = "This class isn't meant to be used directly")]
public static implicit operator Array(DynamicJsonArray obj)
{
return obj._arrayValues;
}
}
/// <summary>
/// Helper to evaluate different method on dynamic objects
/// </summary>
public static class DynamicHelper
{
// We must pass in "object" instead of "dynamic" for the target dynamic object because if we use dynamic, the compiler will
// convert the call to this helper into a dynamic expression, even though we don't need it to be. Since this class is internal,
// it cannot be accessed from a dynamic expression and thus we get errors.
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
public static bool TryGetMemberValue(object obj, string memberName, out object result)
{
try
{
result = GetMemberValue(obj, memberName);
return true;
}
catch (RuntimeBinderException)
{
}
catch (RuntimeBinderInternalCompilerException)
{
}
// We catch the C# specific runtime binder exceptions since we're using the C# binder in this case
result = null;
return false;
}
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "We want to swallow exceptions that happen during runtime binding")]
public static bool TryGetMemberValue(object obj, GetMemberBinder binder, out object result)
{
try
{
// VB us an instance of GetBinderAdapter that does not implement FallbackGetMemeber. This causes lookup of property expressions on dynamic objects to fail.
// Since all types are private to the assembly, we assume that as long as they belong to CSharp runtime, it is the right one.
if (typeof(Binder).Assembly.Equals(binder.GetType().Assembly))
{
// Only use the binder if its a C# binder.
result = GetMemberValue(obj, binder);
}
else
{
result = GetMemberValue(obj, binder.Name);
}
return true;
}
catch
{
result = null;
return false;
}
}
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
public static object GetMemberValue(object obj, string memberName)
{
var callSite = GetMemberAccessCallSite(memberName);
return callSite.Target(callSite, obj);
}
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
public static object GetMemberValue(object obj, GetMemberBinder binder)
{
var callSite = GetMemberAccessCallSite(binder);
return callSite.Target(callSite, obj);
}
// dynamic d = new object();
// object s = d.Name;
// The following code gets generated for this expression:
// callSite = CallSite<Func<CallSite, object, object>>.Create(Binder.GetMember(CSharpBinderFlags.None, "Name", typeof(Program), new CSharpArgumentInfo[] { CSharpArgumentInfo.Create(CSharpArgumentInfoFlags.None, null) }));
// callSite.Target(callSite, d);
// typeof(Program) is the containing type of the dynamic operation.
// Dev10 Bug 914027 - Changed the callsite's target parameter from dynamic to object, see comment at top for details
public static CallSite<Func<CallSite, object, object>> GetMemberAccessCallSite(string memberName)
{
var binder = Binder.GetMember(CSharpBinderFlags.None, memberName, typeof(DynamicHelper), new[] { CSharpArgumentInfo.Create(CSharpArgumentInfoFlags.None, null) });
return GetMemberAccessCallSite(binder);
}
// Dev10 Bug 914027 - Changed the callsite's target parameter from dynamic to object, see comment at top for details
public static CallSite<Func<CallSite, object, object>> GetMemberAccessCallSite(CallSiteBinder binder)
{
return CallSite<Func<CallSite, object, object>>.Create(binder);
}
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
public static IEnumerable<string> GetMemberNames(object obj)
{
var provider = obj as IDynamicMetaObjectProvider;
Debug.Assert(provider != null, "obj doesn't implement IDynamicMetaObjectProvider");
Expression parameter = Expression.Parameter(typeof(object));
return provider.GetMetaObject(parameter).GetDynamicMemberNames();
}
}
}
.NET 4.0有一个内置库可以做到这一点:
using System.Web.Script.Serialization;
JavaScriptSerializer jss = new JavaScriptSerializer();
var d = jss.Deserialize<dynamic>(str);
这是最简单的方法。
在JSON中反序列化。NET可以使用包含在该库中的JObject类来实现动态。我的JSON字符串表示这些类:
public class Foo {
public int Age {get;set;}
public Bar Bar {get;set;}
}
public class Bar {
public DateTime BDay {get;set;}
}
现在我们在不引用上述类的情况下反序列化字符串:
var dyn = JsonConvert.DeserializeObject<JObject>(jsonAsFooString);
JProperty propAge = dyn.Properties().FirstOrDefault(i=>i.Name == "Age");
if(propAge != null) {
int age = int.Parse(propAge.Value.ToString());
Console.WriteLine("age=" + age);
}
//or as a one-liner:
int myage = int.Parse(dyn.Properties().First(i=>i.Name == "Age").Value.ToString());
或者如果你想深入一点:
var propBar = dyn.Properties().FirstOrDefault(i=>i.Name == "Bar");
if(propBar != null) {
JObject o = (JObject)propBar.First();
var propBDay = o.Properties().FirstOrDefault (i => i.Name=="BDay");
if(propBDay != null) {
DateTime bday = DateTime.Parse(propBDay.Value.ToString());
Console.WriteLine("birthday=" + bday.ToString("MM/dd/yyyy"));
}
}
//or as a one-liner:
DateTime mybday = DateTime.Parse(((JObject)dyn.Properties().First(i=>i.Name == "Bar").First()).Properties().First(i=>i.Name == "BDay").Value.ToString());
完整的示例请参见文章。
我使用http://json2csharp.com/来获取表示JSON对象的类。
输入:
{
"name":"John",
"age":31,
"city":"New York",
"Childs":[
{
"name":"Jim",
"age":11
},
{
"name":"Tim",
"age":9
}
]
}
输出:
public class Child
{
public string name { get; set; }
public int age { get; set; }
}
public class Person
{
public string name { get; set; }
public int age { get; set; }
public string city { get; set; }
public List<Child> Childs { get; set; }
}
之后我使用Newtonsoft。Json填充类:
using Newtonsoft.Json;
namespace GitRepositoryCreator.Common
{
class JObjects
{
public static string Get(object p_object)
{
return JsonConvert.SerializeObject(p_object);
}
internal static T Get<T>(string p_object)
{
return JsonConvert.DeserializeObject<T>(p_object);
}
}
}
你可以这样调用它:
Person jsonClass = JObjects.Get<Person>(stringJson);
string stringJson = JObjects.Get(jsonClass);
PS:
如果你的JSON变量名不是一个有效的c#名称(名称以$开头),你可以这样修复:
public class Exception
{
[JsonProperty(PropertyName = "$id")]
public string id { get; set; }
public object innerException { get; set; }
public string message { get; set; }
public string typeName { get; set; }
public string typeKey { get; set; }
public int errorCode { get; set; }
public int eventId { get; set; }
}
你可以使用Newtonsoft。Json
var jRoot =
JsonConvert.DeserializeObject<dynamic>(Encoding.UTF8.GetString(resolvedEvent.Event.Data));
data是我调用core Event得到的响应。
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