我有以下代码:

var user = (Dictionary<string, object>)serializer.DeserializeObject(responsecontent);

responsecontent中的输入是JSON,但它没有正确地反序列化为对象。我应该如何正确地反序列化它?


当前回答

您还可以查看DataContractJsonSerializer

其他回答

试试下面的代码:

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("URL");
JArray array = new JArray();
using (var twitpicResponse = (HttpWebResponse)request.GetResponse())
using (var reader = new StreamReader(twitpicResponse.GetResponseStream()))
{
    JavaScriptSerializer js = new JavaScriptSerializer();
    var objText = reader.ReadToEnd();

    JObject joResponse = JObject.Parse(objText);
    JObject result = (JObject)joResponse["result"];
    array = (JArray)result["Detail"];
    string statu = array[0]["dlrStat"].ToString();
}

我最终创建了一个简单的类,可以动态地创建类型,实例化它们并将它们水合物化,镜像输入JSON的结构。

你可以在这里找到它:

https://github.com/starnutoditopo/JsonToObject

JsonToObjectConverter.cs

using System.Globalization;
using System.Reflection;
using System.Reflection.Emit;
using System.Text.Json;

namespace JsonToObject;

/// <summary>Provides functionalities to convert JSON strings in to CLR objects.</summary>
public class JsonToObjectConverter
{
    private class Counter
    {
        private ulong count;
        public Counter()
        {
            this.count = 0;
        }

        public ulong Next()
        {
            this.count++;
            return this.count;
        }
    }


    private static ulong assemblyGenerationCounter;
    private readonly JsonToObjectConverterOptions options;

    static JsonToObjectConverter()
    {
        assemblyGenerationCounter = 0;
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="JsonToObjectConverter" /> class, using default options.
    /// </summary>
    /// <param name="options">The options.</param>
    public JsonToObjectConverter()
        : this(new JsonToObjectConverterOptions())
    {
    }


    /// <summary>
    /// Initializes a new instance of the <see cref="JsonToObjectConverter" /> class, using the specified options.
    /// </summary>
    /// <param name="options">The options.</param>
    public JsonToObjectConverter(JsonToObjectConverterOptions options)
    {
        this.options = options;
    }

    /// <summary>Converts a JSON string to an instance of a CLR object.</summary>
    /// <param name="jsonString">The json string.</param>
    /// <returns>
    ///   <br />
    /// </returns>
    public object? ConvertToObject(string jsonString)
    {
        JsonSerializerOptions opt = new JsonSerializerOptions()
        {
            PropertyNameCaseInsensitive = true
        };
        JsonElement rawResult = JsonSerializer.Deserialize<JsonElement>(jsonString, opt);
        object? result = ToStronglyTypedObject(rawResult);
        return result;
    }

    private object? ToStronglyTypedObject(JsonElement? nullableJsonElement)
    {
        string assemblyNameString;
        ulong assemblyId = Interlocked.Increment(ref assemblyGenerationCounter);
        try
        {
            assemblyNameString = string.Format(this.options.RuntimeGeneratedAssemblyNameTemplate, assemblyId.ToString(CultureInfo.InvariantCulture));
        }
        catch
        {
            throw new InvalidOperationException($@"Unable to generate assembly name using template '{this.options.RuntimeGeneratedAssemblyNameTemplate}' and id '{assemblyId}'. Please, review the {nameof(JsonToObjectConverterOptions.RuntimeGeneratedAssemblyNameTemplate)} property in the options.");
        }
        ModuleBuilder moduleBuilder = CreateModuleBuilder(assemblyNameString, this.options.RuntimeGeneratedModuleName);
        Counter typeGenerationCounter = new Counter();
        var result = ToStronglyTypedObject(nullableJsonElement, moduleBuilder, typeGenerationCounter);
        return result;
    }
    private object? ToStronglyTypedObject(
        JsonElement? nullableJsonElement,
        ModuleBuilder moduleBuilder,
        Counter typeGenerationCounter
    )
    {
        if (nullableJsonElement == null)
        {
            return null;
        }

        JsonElement jsonElement = nullableJsonElement.Value;

        switch (jsonElement.ValueKind)
        {
            case JsonValueKind.Undefined:
                return null;
            case JsonValueKind.String:
                return jsonElement.GetString();
            case JsonValueKind.False:
                return false;
            case JsonValueKind.True:
                return true;
            case JsonValueKind.Null:
                return null;
            case JsonValueKind.Number:
                {
                    if (jsonElement.TryGetDouble(out var result))
                    {
                        return result;
                    }
                }
                throw new InvalidOperationException($"Unable to parse {jsonElement} as number.");
            case JsonValueKind.Object:
                {
                    ulong typeId = typeGenerationCounter.Next();
                    string typeName;
                    try
                    {
                        typeName = string.Format(this.options.RuntimeGeneratedTypeNameTemplate, typeId.ToString(CultureInfo.InvariantCulture));
                    }
                    catch
                    {
                        throw new InvalidOperationException($@"Unable to generate type name using template '{this.options.RuntimeGeneratedTypeNameTemplate}' and id '{typeId}'. Please, review the {nameof(JsonToObjectConverterOptions.RuntimeGeneratedTypeNameTemplate)} property in the options.");
                    }

                    TypeBuilder typeBuilder = CreateTypeBuilder(moduleBuilder, typeName);
                    Dictionary<string, object?> propertyValues = new Dictionary<string, object?>();
                    foreach (var property in jsonElement.EnumerateObject())
                    {
                        string propertyName = property.Name;
                        object? propertyValue = ToStronglyTypedObject(property.Value, moduleBuilder, typeGenerationCounter);
                        Type propertyValueType;
                        if (null == propertyValue)
                        {
                            propertyValueType = typeof(object);
                        }
                        else
                        {
                            propertyValueType = propertyValue.GetType();
                        }
                        CreateAutoImplementedProperty(typeBuilder, propertyName, propertyValueType);
                        propertyValues.Add(propertyName, propertyValue);
                    }

                    Type resultType = typeBuilder.CreateType()!;
                    object result = Activator.CreateInstance(resultType)!;
                    foreach (var pair in propertyValues)
                    {
                        var propertyInfo = resultType.GetProperty(pair.Key)!;
                        propertyInfo.SetValue(result, pair.Value);
                    }
                    return result;
                }
            case JsonValueKind.Array:
                {
                    List<object?> list = new List<object?>();
                    foreach (var item in jsonElement.EnumerateArray())
                    {
                        object? value = ToStronglyTypedObject(item, moduleBuilder, typeGenerationCounter);
                        list.Add(value);
                    }
                    return list.ToArray();
                }
            default:
                throw new InvalidOperationException($"Value type '{jsonElement.ValueKind}' is not supported");
        }
    }

    private static ModuleBuilder CreateModuleBuilder(
            string assemblyNameString,
            string moduleName
        )
    {
        // create assembly name
        var assemblyName = new AssemblyName(assemblyNameString);
        // create the assembly builder
        AssemblyBuilder assemblyBuilder = AssemblyBuilder.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run);

        // create the module builder
        ModuleBuilder moduleBuilder = assemblyBuilder.DefineDynamicModule(moduleName);
        return moduleBuilder;
    }

    private static TypeBuilder CreateTypeBuilder(
            ModuleBuilder moduleBuilder,
            string typeName
        )
    {
        // create the type builder
        TypeBuilder typeBuilder = moduleBuilder.DefineType(typeName, TypeAttributes.Public);
        typeBuilder.DefineDefaultConstructor(MethodAttributes.Public);
        return typeBuilder;
    }

    private static void CreateAutoImplementedProperty(
        TypeBuilder builder,
        string propertyName,
        Type propertyType
        )
    {
        const string PrivateFieldPrefix = "m_";
        const string GetterPrefix = "get_";
        const string SetterPrefix = "set_";

        // Generate the field.
        FieldBuilder fieldBuilder = builder.DefineField(
            string.Concat(PrivateFieldPrefix, propertyName),
                          propertyType, FieldAttributes.Private);

        // Generate the property
        PropertyBuilder propertyBuilder = builder.DefineProperty(
            propertyName, PropertyAttributes.HasDefault, propertyType, null);

        // Property getter and setter attributes.
        MethodAttributes propertyMethodAttributes =
            MethodAttributes.Public | MethodAttributes.SpecialName |
            MethodAttributes.HideBySig;

        // Define the getter method.
        MethodBuilder getterMethod = builder.DefineMethod(
            string.Concat(GetterPrefix, propertyName),
            propertyMethodAttributes, propertyType, Type.EmptyTypes);

        // Emit the IL code.
        // ldarg.0
        // ldfld,_field
        // ret
        ILGenerator getterILCode = getterMethod.GetILGenerator();
        getterILCode.Emit(OpCodes.Ldarg_0);
        getterILCode.Emit(OpCodes.Ldfld, fieldBuilder);
        getterILCode.Emit(OpCodes.Ret);

        // Define the setter method.
        MethodBuilder setterMethod = builder.DefineMethod(
            string.Concat(SetterPrefix, propertyName),
            propertyMethodAttributes, null, new Type[] { propertyType });

        // Emit the IL code.
        // ldarg.0
        // ldarg.1
        // stfld,_field
        // ret
        ILGenerator setterILCode = setterMethod.GetILGenerator();
        setterILCode.Emit(OpCodes.Ldarg_0);
        setterILCode.Emit(OpCodes.Ldarg_1);
        setterILCode.Emit(OpCodes.Stfld, fieldBuilder);
        setterILCode.Emit(OpCodes.Ret);

        propertyBuilder.SetGetMethod(getterMethod);
        propertyBuilder.SetSetMethod(setterMethod);
    }
}

JsonToObjectConverterOptions.cs

namespace JsonToObject;

/// <summary>
/// Defines the options to instantiate a <see cref="JsonToObjectConverter" /> object.
/// </summary>
public class JsonToObjectConverterOptions
{
    private const string CONSTANTS_RuntimeGeneratedModuleName = $"RuntimeGeneratedModule";
    private const string CONSTANTS_RuntimeGeneratedAssemblyNameTemplate = "RuntimeGeneratedAssembly_{0}";
    private const string CONSTANTS_RuntimeGeneratedTypeNameTemplate = "RuntimeGeneratedType_{0}";

    /// <summary>Gets or sets the name of the runtime-generated module.</summary>
    /// <value>The name of the runtime-generated module.</value>
    public string RuntimeGeneratedModuleName { get; set; } = CONSTANTS_RuntimeGeneratedModuleName;

    /// <summary>Gets or sets the template to use to generate the name of runtime-generated assemblies.</summary>
    /// <value>The template to use to generate the name of runtime-generated assemblies.</value>
    /// <remarks>Should contain a "{0}" placeholder.</remarks>
    public string RuntimeGeneratedAssemblyNameTemplate { get; set; } = CONSTANTS_RuntimeGeneratedAssemblyNameTemplate;

    /// <summary>Gets or sets the template to use to generate the name of runtime-generated types.</summary>
    /// <value>The template to use to generate the name of runtime-generated types.</value>
    /// <remarks>Should contain a "{0}" placeholder.</remarks>
    public string RuntimeGeneratedTypeNameTemplate { get; set; } = CONSTANTS_RuntimeGeneratedTypeNameTemplate;
}

如果您可以使用。net 4,请查看:http://visitmix.com/writings/the-rise-of-json (archive.org)

以下是该网站的一个片段:

WebClient webClient = new WebClient();
dynamic result = JsonValue.Parse(webClient.DownloadString("https://api.foursquare.com/v2/users/self?oauth_token=XXXXXXX"));
Console.WriteLine(result.response.user.firstName);

最后一个控制台。WriteLine很贴心…

这里有一些不使用第三方库的选项:

// For that you will need to add reference to System.Runtime.Serialization
var jsonReader = JsonReaderWriterFactory.CreateJsonReader(Encoding.UTF8.GetBytes(@"{ ""Name"": ""Jon Smith"", ""Address"": { ""City"": ""New York"", ""State"": ""NY"" }, ""Age"": 42 }"), new System.Xml.XmlDictionaryReaderQuotas());

// For that you will need to add reference to System.Xml and System.Xml.Linq
var root = XElement.Load(jsonReader);
Console.WriteLine(root.XPathSelectElement("//Name").Value);
Console.WriteLine(root.XPathSelectElement("//Address/State").Value);

// For that you will need to add reference to System.Web.Helpers
dynamic json = System.Web.Helpers.Json.Decode(@"{ ""Name"": ""Jon Smith"", ""Address"": { ""City"": ""New York"", ""State"": ""NY"" }, ""Age"": 42 }");
Console.WriteLine(json.Name);
Console.WriteLine(json.Address.State);

有关System.Web.Helpers.Json的更多信息,请参阅链接。

更新:现在最简单的上网方式。helper是使用NuGet包的。


如果你不关心早期的windows版本,你可以使用windows . data . json命名空间的类:

// minimum supported version: Win 8
JsonObject root = Windows.Data.Json.JsonValue.Parse(jsonString).GetObject();
Console.WriteLine(root["Name"].GetString());
Console.WriteLine(root["Address"].GetObject()["State"].GetString());

我认为我所见过的最好的回答是@MD_Sayem_Ahmed。

你的问题是“如何用c#解析Json”,但看起来你想解码Json。如果你想要解读它,艾哈迈德的答案很好。

如果您试图在ASP中完成此任务。NET Web Api,最简单的方法是创建一个数据传输对象,其中包含你想要分配的数据:

public class MyDto{
    public string Name{get; set;}
    public string Value{get; set;}
}

您只需将application/json头添加到您的请求(例如,如果您使用Fiddler)。 然后在ASP中使用它。NET Web API如下:

//controller method -- assuming you want to post and return data
public MyDto Post([FromBody] MyDto myDto){
   MyDto someDto = myDto;
   /*ASP.NET automatically converts the data for you into this object 
    if you post a json object as follows:
{
    "Name": "SomeName",
      "Value": "SomeValue"
}
*/
   //do some stuff
}

这在我开发Web Api时给了我很大的帮助,使我的生活变得超级简单。