Question

是否有任何优雅的快速方法将对象映射到字典，反之亦然？

实施例

IDictionary<string,object> a = new Dictionary<string,object>();
a["Id"]=1;
a["Name"]="Ahmad";
// .....

变为

SomeClass b = new SomeClass();
b.Id=1;
b.Name="Ahmad";
// ..........

Answer 1

在两种扩展方法中使用一些反射和泛型可以实现这一点。

是的，其他人做了大部分相同的解决方案，但这使用较少的反射，这在性能方面更具可读性：

public static class ObjectExtensions
{
    public static T ToObject<T>(this IDictionary<string, object> source)
        where T : class, new()
    {
            var someObject = new T();
            var someObjectType = someObject.GetType();

            foreach (var item in source)
            {
                someObjectType
                         .GetProperty(item.Key)
                         .SetValue(someObject, item.Value, null);
            }

            return someObject;
    }

    public static IDictionary<string, object> AsDictionary(this object source, BindingFlags bindingAttr = BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.Instance)
    {
        return source.GetType().GetProperties(bindingAttr).ToDictionary
        (
            propInfo => propInfo.Name,
            propInfo => propInfo.GetValue(source, null)
        );

    }
}

class A
{
    public string Prop1
    {
        get;
        set;
    }

    public int Prop2
    {
        get;
        set;
    }
}

class Program
{
    static void Main(string[] args)
    {
        Dictionary<string, object> dictionary = new Dictionary<string, object>();
        dictionary.Add("Prop1", "hello world!");
        dictionary.Add("Prop2", 3893);
        A someObject = dictionary.ToObject<A>();

        IDictionary<string, object> objectBackToDictionary = someObject.AsDictionary();
    }
}

Answer 2

似乎反射只有帮助。我已经完成了将对象转换为字典的小例子，反之亦然：

[TestMethod]
public void DictionaryTest()
{
    var item = new SomeCLass { Id = "1", Name = "name1" };
    IDictionary<string, object> dict = ObjectToDictionary<SomeCLass>(item);
    var obj = ObjectFromDictionary<SomeCLass>(dict);
}

private T ObjectFromDictionary<T>(IDictionary<string, object> dict)
    where T : class 
{
    Type type = typeof(T);
    T result = (T)Activator.CreateInstance(type);
    foreach (var item in dict)
    {
        type.GetProperty(item.Key).SetValue(result, item.Value, null);
    }
    return result;
}

private IDictionary<string, object> ObjectToDictionary<T>(T item)
    where T: class
{
    Type myObjectType = item.GetType();
    IDictionary<string, object> dict = new Dictionary<string, object>();
    var indexer = new object[0];
    PropertyInfo[] properties = myObjectType.GetProperties();
    foreach (var info in properties)
    {
        var value = info.GetValue(item, indexer);
        dict.Add(info.Name, value);
    }
    return dict;
}

Answer 3

首先使用Newtonsoft将Dictionary转换为JSON字符串。

var json = JsonConvert.SerializeObject(advancedSettingsDictionary, Newtonsoft.Json.Formatting.Indented);

然后将JSON字符串反序列化为对象

var myobject = JsonConvert.DeserializeObject<AOCAdvancedSettings>(json);

Answer 4

我强烈推荐Castle DictionaryAdapter，这是该项目保存最好的秘密之一。您只需要定义一个具有所需属性的接口，并在一行代码中，适配器将生成一个实现，实例化它，并将其值与您传入的字典同步。我用它来强类型我的AppSettings in一个网络项目：

var appSettings =
  new DictionaryAdapterFactory().GetAdapter<IAppSettings>(ConfigurationManager.AppSettings);

请注意，我不需要创建一个实现IAppSettings的类 - 适配器即时执行。此外，虽然在这种情况下我只是阅读，理论上如果我在appSettings上设置属性值，适配器会使基础字典与这些更改保持同步。

Answer 5

通过遍历属性，反射可以将您从对象带到字典。

换句话说，你必须在C＃中使用动态ExpandoObject（实际上已经从IDictionary继承了，所以已经为你完成了这个），除非你能推断出类型以某种方式从字典中的条目集合。

所以，如果你在.NET 4.0中，请使用ExpandoObject，否则你需要做很多工作......

Answer 6

我认为你应该使用反思。像这样：

private T ConvertDictionaryTo<T>(IDictionary<string, object> dictionary) where T : new()
{
    Type type = typeof (T);
    T ret = new T();

    foreach (var keyValue in dictionary)
    {
        type.GetProperty(keyValue.Key).SetValue(ret, keyValue.Value, null);
    }

    return ret;
}

它需要你的字典并循环遍历它并设置值。你应该做得更好，但这是一个开始。你应该这样称呼它：

SomeClass someClass = ConvertDictionaryTo<SomeClass>(a);

Answer 7

public class SimpleObjectDictionaryMapper<TObject>
{
    public static TObject GetObject(IDictionary<string, object> d)
    {
        PropertyInfo[] props = typeof(TObject).GetProperties();
        TObject res = Activator.CreateInstance<TObject>();
        for (int i = 0; i < props.Length; i++)
        {
            if (props[i].CanWrite && d.ContainsKey(props[i].Name))
            {
                props[i].SetValue(res, d[props[i].Name], null);
            }
        }
        return res;
    }

    public static IDictionary<string, object> GetDictionary(TObject o)
    {
        IDictionary<string, object> res = new Dictionary<string, object>();
        PropertyInfo[] props = typeof(TObject).GetProperties();
        for (int i = 0; i < props.Length; i++)
        {
            if (props[i].CanRead)
            {
                res.Add(props[i].Name, props[i].GetValue(o, null));
            }
        }
        return res;
    }
}

Answer 8

基于MatíasFidemraizer的回答，这里有一个支持绑定除字符串以外的对象属性的版本。

using System.Collections.Generic;
using System.Linq;
using System.Reflection;

namespace WebOpsApi.Shared.Helpers
{
    public static class MappingExtension
    {
        public static T ToObject<T>(this IDictionary<string, object> source)
            where T : class, new()
        {
            var someObject = new T();
            var someObjectType = someObject.GetType();

            foreach (var item in source)
            {
                var key = char.ToUpper(item.Key[0]) + item.Key.Substring(1);
                var targetProperty = someObjectType.GetProperty(key);


                if (targetProperty.PropertyType == typeof (string))
                {
                    targetProperty.SetValue(someObject, item.Value);
                }
                else
                {

                    var parseMethod = targetProperty.PropertyType.GetMethod("TryParse",
                        BindingFlags.Public | BindingFlags.Static, null,
                        new[] {typeof (string), targetProperty.PropertyType.MakeByRefType()}, null);

                    if (parseMethod != null)
                    {
                        var parameters = new[] { item.Value, null };
                        var success = (bool)parseMethod.Invoke(null, parameters);
                        if (success)
                        {
                            targetProperty.SetValue(someObject, parameters[1]);
                        }

                    }
                }
            }

            return someObject;
        }

        public static IDictionary<string, object> AsDictionary(this object source, BindingFlags bindingAttr = BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.Instance)
        {
            return source.GetType().GetProperties(bindingAttr).ToDictionary
            (
                propInfo => propInfo.Name,
                propInfo => propInfo.GetValue(source, null)
            );
        }
    }
}

Answer 9

如果您使用的是Asp.Net MVC，请查看：

public static RouteValueDictionary AnonymousObjectToHtmlAttributes(object htmlAttributes);

这是System.Web.Mvc.HtmlHelper类上的静态公共方法。

Answer 10

    public Dictionary<string, object> ToDictionary<T>(string key, T value)
    {
        try
        {
            var payload = new Dictionary<string, object>
            {
                { key, value }
            }; 
        } catch (Exception e)
        {
            return null;
        }
    }

    public T FromDictionary<T>(Dictionary<string, object> payload, string key)
    {
        try
        {
            JObject jObject = (JObject) payload[key];
            T t = jObject.ToObject<T>();
            return (t);
        }
        catch(Exception e) {
            return default(T);
        }
    }

将对象映射到字典，反之亦然

实施例

10 个答案: