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。

我想在单元测试中以编程的方式完成，我可以把它打出来。

我的解决方案是:

var dict = JsonConvert.DeserializeObject<ExpandoObject>(json) as IDictionary<string, object>;

现在我可以断言

dict.ContainsKey("ExpectedProperty");

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。

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();
        }
    }

}

c#有一个轻量级JSON库，叫做SimpleJson。

它支持。net 3.5+， Silverlight和Windows Phone 7。

它支持。net 4.0的动态

它也可以作为NuGet包安装

Install-Package SimpleJson