转换字典 < string，Object > 为匿名对象？

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Anonymous objects are one that generated for you by compiler. You cannot generate dynamically create one. On the other hand you can emit such object, but I really do not think this is good idea.

May be you can try dynamic objects? The result will be an object with all properties you need.

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最佳答案

If you really want to convert the dictionary to an object that has the items of the dictionary as properties, you can use ExpandoObject:

var dict = new Dictionary<string, object> { { "Property", "foo" } };
var eo = new ExpandoObject();
var eoColl = (ICollection<KeyValuePair<string, object>>)eo;


foreach (var kvp in dict)
{
eoColl.Add(kvp);
}


dynamic eoDynamic = eo;


string value = eoDynamic.Property;

小开

If you have a class you want to covert the dictionary too, you can use the following to convert a dictionary to an object of that class:

Example class:

public class Properties1
{
public string Property { get; set; }
}

The solution:

JavaScriptSerializer serializer = new JavaScriptSerializer();
Dictionary<string, object> dict = new Dictionary<string, object> { { "Property", "foo" } };
Properties1 properties = serializer.ConvertToType<Properties1>(dict);
string value = properties.Property;

You could also use a method like this to build the object from the dictionary, obviously this also requires you to have a class.

private static T DictionaryToObject<T>(IDictionary<string, object> dict) where T : new()
{
T t = new T();
PropertyInfo[] properties = t.GetType().GetProperties();


foreach (PropertyInfo property in properties)
{
if (!dict.Any(x => x.Key.Equals(property.Name,
StringComparison.InvariantCultureIgnoreCase)))
continue;
KeyValuePair<string, object> item = dict.First(x => x.Key.Equals(property.Name,
StringComparison.InvariantCultureIgnoreCase));
Type tPropertyType = t.GetType().GetProperty(property.Name).PropertyType;
Type newT = Nullable.GetUnderlyingType(tPropertyType) ?? tPropertyType;
object newA = Convert.ChangeType(item.Value, newT);
t.GetType().GetProperty(property.Name).SetValue(t, newA, null);
}
return t;
}

However if you do not have the class you can create a dynamic object from a dictionary like this:

private static dynamic DictionaryToObject(Dictionary<string, object> dict)
{
IDictionary<string, object> eo = (IDictionary<string, object>)new ExpandoObject();
foreach (KeyValuePair<string, object> kvp in dict)
{
eo.Add(kvp);
}
return eo;
}

You can use it like this:

Dictionary<string, object> dict = new Dictionary<string, object> \{\{ "Property", "foo" }};
dynamic properties = DictionaryToObject(dict);
string value = properties.Property;

小开

If you want to convert Dictionary<string, object> To Anonymous System.Object. You can use this method:

public static object FromDictToAnonymousObj<TValue>(IDictionary<string, TValue> dict)
{
var types = new Type[dict.Count];


for (int i = 0; i < types.Length; i++)
{
types[i] = typeof(TValue);
}


// dictionaries don't have an order, so we force an order based
// on the Key
var ordered = dict.OrderBy(x => x.Key).ToArray();


string[] names = Array.ConvertAll(ordered, x => x.Key);


Type type = AnonymousType.CreateType(types, names);


object[] values = Array.ConvertAll(ordered, x => (object)x.Value);


object obj = type.GetConstructor(types).Invoke(values);


return obj;
}

like this:

var dict = new Dictionary<string, string>
{
{"Id", "1"},
{"Title", "My title"},
{"Description", "Blah blah blah"},
};


object obj1 = FromDictToAnonymousObj(dict);

to obtain your object. Where AnonymousType class code is:

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading;


/// <summary>
/// The code generated should be nearly equal to the one generated by
/// csc 12.0.31101.0 when compiling with /optimize+ /debug-. The main
/// difference is in the GetHashCode() (the base init_hash used is
/// compiler-dependant) and in the maxstack of the generated methods.
/// Note that Roslyn (at least the one present at
/// tryroslyn.azurewebsites.net) generates different code for anonymous
/// types.
/// </summary>
public static class AnonymousType
{
private static readonly ConcurrentDictionary<string, Type> GeneratedTypes = new ConcurrentDictionary<string, Type>();


private static readonly AssemblyBuilder AssemblyBuilder;
private static readonly ModuleBuilder ModuleBuilder;
private static readonly string FileName;


// Some objects we cache
private static readonly CustomAttributeBuilder CompilerGeneratedAttributeBuilder = new CustomAttributeBuilder(typeof(CompilerGeneratedAttribute).GetConstructor(Type.EmptyTypes), new object[0]);
private static readonly CustomAttributeBuilder DebuggerBrowsableAttributeBuilder = new CustomAttributeBuilder(typeof(DebuggerBrowsableAttribute).GetConstructor(new[] { typeof(DebuggerBrowsableState) }), new object[] { DebuggerBrowsableState.Never });
private static readonly CustomAttributeBuilder DebuggerHiddenAttributeBuilder = new CustomAttributeBuilder(typeof(DebuggerHiddenAttribute).GetConstructor(Type.EmptyTypes), new object[0]);


private static readonly ConstructorInfo ObjectCtor = typeof(object).GetConstructor(Type.EmptyTypes);
private static readonly MethodInfo ObjectToString = typeof(object).GetMethod("ToString", BindingFlags.Instance | BindingFlags.Public, null, Type.EmptyTypes, null);


private static readonly ConstructorInfo StringBuilderCtor = typeof(StringBuilder).GetConstructor(Type.EmptyTypes);
private static readonly MethodInfo StringBuilderAppendString = typeof(StringBuilder).GetMethod("Append", BindingFlags.Instance | BindingFlags.Public, null, new[] { typeof(string) }, null);
private static readonly MethodInfo StringBuilderAppendObject = typeof(StringBuilder).GetMethod("Append", BindingFlags.Instance | BindingFlags.Public, null, new[] { typeof(object) }, null);


private static readonly Type EqualityComparer = typeof(EqualityComparer<>);
private static readonly Type EqualityComparerGenericArgument = EqualityComparer.GetGenericArguments()[0];
private static readonly MethodInfo EqualityComparerDefault = EqualityComparer.GetMethod("get_Default", BindingFlags.Static | BindingFlags.Public, null, Type.EmptyTypes, null);
private static readonly MethodInfo EqualityComparerEquals = EqualityComparer.GetMethod("Equals", BindingFlags.Instance | BindingFlags.Public, null, new[] { EqualityComparerGenericArgument, EqualityComparerGenericArgument }, null);
private static readonly MethodInfo EqualityComparerGetHashCode = EqualityComparer.GetMethod("GetHashCode", BindingFlags.Instance | BindingFlags.Public, null, new[] { EqualityComparerGenericArgument }, null);


private static int Index = -1;


static AnonymousType()
{
var assemblyName = new AssemblyName("AnonymousTypes");


FileName = assemblyName.Name + ".dll";


AssemblyBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.RunAndSave);
ModuleBuilder = AssemblyBuilder.DefineDynamicModule("AnonymousTypes", FileName);
}


public static void Dump()
{
AssemblyBuilder.Save(FileName);
}


/// <summary>
///
/// </summary>
/// <param name="types"></param>
/// <param name="names"></param>
/// <returns></returns>
public static Type CreateType(Type[] types, string[] names)
{
if (types == null)
{
throw new ArgumentNullException("types");
}


if (names == null)
{
throw new ArgumentNullException("names");
}


if (types.Length != names.Length)
{
throw new ArgumentException("names");
}


// Anonymous classes are generics based. The generic classes
// are distinguished by number of parameters and name of
// parameters. The specific types of the parameters are the
// generic arguments. We recreate this by creating a fullName
// composed of all the property names, separated by a "|"
string fullName = string.Join("|", names.Select(x => Escape(x)));


Type type;


if (!GeneratedTypes.TryGetValue(fullName, out type))
{
// We create only a single class at a time, through this lock
// Note that this is a variant of the double-checked locking.
// It is safe because we are using a thread safe class.
lock (GeneratedTypes)
{
if (!GeneratedTypes.TryGetValue(fullName, out type))
{
int index = Interlocked.Increment(ref Index);


string name = names.Length != 0 ? string.Format("<>f__AnonymousType{0}`{1}", index, names.Length) : string.Format("<>f__AnonymousType{0}", index);
TypeBuilder tb = ModuleBuilder.DefineType(name, TypeAttributes.AnsiClass | TypeAttributes.Class | TypeAttributes.AutoLayout | TypeAttributes.NotPublic | TypeAttributes.Sealed | TypeAttributes.BeforeFieldInit);
tb.SetCustomAttribute(CompilerGeneratedAttributeBuilder);


GenericTypeParameterBuilder[] generics = null;


if (names.Length != 0)
{
string[] genericNames = Array.ConvertAll(names, x => string.Format("<{0}>j__TPar", x));
generics = tb.DefineGenericParameters(genericNames);
}
else
{
generics = new GenericTypeParameterBuilder[0];
}


// .ctor
ConstructorBuilder constructor = tb.DefineConstructor(MethodAttributes.Public | MethodAttributes.HideBySig, CallingConventions.HasThis, generics);
constructor.SetCustomAttribute(DebuggerHiddenAttributeBuilder);
ILGenerator ilgeneratorConstructor = constructor.GetILGenerator();
ilgeneratorConstructor.Emit(OpCodes.Ldarg_0);
ilgeneratorConstructor.Emit(OpCodes.Call, ObjectCtor);


var fields = new FieldBuilder[names.Length];


// There are two for cycles because we want to have
// all the getter methods before all the other
// methods
for (int i = 0; i < names.Length; i++)
{
// field
fields[i] = tb.DefineField(string.Format("<{0}>i__Field", names[i]), generics[i], FieldAttributes.Private | FieldAttributes.InitOnly);
fields[i].SetCustomAttribute(DebuggerBrowsableAttributeBuilder);


// .ctor
constructor.DefineParameter(i + 1, ParameterAttributes.None, names[i]);
ilgeneratorConstructor.Emit(OpCodes.Ldarg_0);


if (i == 0)
{
ilgeneratorConstructor.Emit(OpCodes.Ldarg_1);
}
else if (i == 1)
{
ilgeneratorConstructor.Emit(OpCodes.Ldarg_2);
}
else if (i == 2)
{
ilgeneratorConstructor.Emit(OpCodes.Ldarg_3);
}
else if (i < 255)
{
ilgeneratorConstructor.Emit(OpCodes.Ldarg_S, (byte)(i + 1));
}
else
{
// Ldarg uses a ushort, but the Emit only
// accepts short, so we use a unchecked(...),
// cast to short and let the CLR interpret it
// as ushort
ilgeneratorConstructor.Emit(OpCodes.Ldarg, unchecked((short)(i + 1)));
}


ilgeneratorConstructor.Emit(OpCodes.Stfld, fields[i]);


// getter
MethodBuilder getter = tb.DefineMethod(string.Format("get_{0}", names[i]), MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.SpecialName, CallingConventions.HasThis, generics[i], Type.EmptyTypes);
ILGenerator ilgeneratorGetter = getter.GetILGenerator();
ilgeneratorGetter.Emit(OpCodes.Ldarg_0);
ilgeneratorGetter.Emit(OpCodes.Ldfld, fields[i]);
ilgeneratorGetter.Emit(OpCodes.Ret);


PropertyBuilder property = tb.DefineProperty(names[i], PropertyAttributes.None, CallingConventions.HasThis, generics[i], Type.EmptyTypes);
property.SetGetMethod(getter);
}


// ToString()
MethodBuilder toString = tb.DefineMethod("ToString", MethodAttributes.Public | MethodAttributes.Virtual | MethodAttributes.HideBySig, CallingConventions.HasThis, typeof(string), Type.EmptyTypes);
toString.SetCustomAttribute(DebuggerHiddenAttributeBuilder);
ILGenerator ilgeneratorToString = toString.GetILGenerator();


ilgeneratorToString.DeclareLocal(typeof(StringBuilder));


ilgeneratorToString.Emit(OpCodes.Newobj, StringBuilderCtor);
ilgeneratorToString.Emit(OpCodes.Stloc_0);


// Equals
MethodBuilder equals = tb.DefineMethod("Equals", MethodAttributes.Public | MethodAttributes.Virtual | MethodAttributes.HideBySig, CallingConventions.HasThis, typeof(bool), new[] { typeof(object) });
equals.SetCustomAttribute(DebuggerHiddenAttributeBuilder);
equals.DefineParameter(1, ParameterAttributes.None, "value");
ILGenerator ilgeneratorEquals = equals.GetILGenerator();
ilgeneratorEquals.DeclareLocal(tb);


ilgeneratorEquals.Emit(OpCodes.Ldarg_1);
ilgeneratorEquals.Emit(OpCodes.Isinst, tb);
ilgeneratorEquals.Emit(OpCodes.Stloc_0);
ilgeneratorEquals.Emit(OpCodes.Ldloc_0);


Label equalsLabel = ilgeneratorEquals.DefineLabel();


// GetHashCode()
MethodBuilder getHashCode = tb.DefineMethod("GetHashCode", MethodAttributes.Public | MethodAttributes.Virtual | MethodAttributes.HideBySig, CallingConventions.HasThis, typeof(int), Type.EmptyTypes);
getHashCode.SetCustomAttribute(DebuggerHiddenAttributeBuilder);
ILGenerator ilgeneratorGetHashCode = getHashCode.GetILGenerator();
ilgeneratorGetHashCode.DeclareLocal(typeof(int));


if (names.Length == 0)
{
ilgeneratorGetHashCode.Emit(OpCodes.Ldc_I4_0);
}
else
{
// As done by Roslyn
// Note that initHash can vary, because
// string.GetHashCode() isn't "stable" for
// different compilation of the code
int initHash = 0;


for (int i = 0; i < names.Length; i++)
{
initHash = unchecked(initHash * (-1521134295) + fields[i].Name.GetHashCode());
}


// Note that the CSC seems to generate a
// different seed for every anonymous class
ilgeneratorGetHashCode.Emit(OpCodes.Ldc_I4, initHash);
}


for (int i = 0; i < names.Length; i++)
{
// Equals()
Type equalityComparerT = EqualityComparer.MakeGenericType(generics[i]);
MethodInfo equalityComparerTDefault = TypeBuilder.GetMethod(equalityComparerT, EqualityComparerDefault);
MethodInfo equalityComparerTEquals = TypeBuilder.GetMethod(equalityComparerT, EqualityComparerEquals);


ilgeneratorEquals.Emit(OpCodes.Brfalse_S, equalsLabel);
ilgeneratorEquals.Emit(OpCodes.Call, equalityComparerTDefault);
ilgeneratorEquals.Emit(OpCodes.Ldarg_0);
ilgeneratorEquals.Emit(OpCodes.Ldfld, fields[i]);
ilgeneratorEquals.Emit(OpCodes.Ldloc_0);
ilgeneratorEquals.Emit(OpCodes.Ldfld, fields[i]);
ilgeneratorEquals.Emit(OpCodes.Callvirt, equalityComparerTEquals);


// GetHashCode();
MethodInfo EqualityComparerTGetHashCode = TypeBuilder.GetMethod(equalityComparerT, EqualityComparerGetHashCode);


ilgeneratorGetHashCode.Emit(OpCodes.Stloc_0);
ilgeneratorGetHashCode.Emit(OpCodes.Ldc_I4, -1521134295);
ilgeneratorGetHashCode.Emit(OpCodes.Ldloc_0);
ilgeneratorGetHashCode.Emit(OpCodes.Mul);
ilgeneratorGetHashCode.Emit(OpCodes.Call, EqualityComparerDefault);
ilgeneratorGetHashCode.Emit(OpCodes.Ldarg_0);
ilgeneratorGetHashCode.Emit(OpCodes.Ldfld, fields[i]);
ilgeneratorGetHashCode.Emit(OpCodes.Callvirt, EqualityComparerGetHashCode);
ilgeneratorGetHashCode.Emit(OpCodes.Add);


// ToString()
ilgeneratorToString.Emit(OpCodes.Ldloc_0);
ilgeneratorToString.Emit(OpCodes.Ldstr, i == 0 ? string.Format("\{\{ {0} = ", names[i]) : string.Format(", {0} = ", names[i]));
ilgeneratorToString.Emit(OpCodes.Callvirt, StringBuilderAppendString);
ilgeneratorToString.Emit(OpCodes.Pop);
ilgeneratorToString.Emit(OpCodes.Ldloc_0);
ilgeneratorToString.Emit(OpCodes.Ldarg_0);
ilgeneratorToString.Emit(OpCodes.Ldfld, fields[i]);
ilgeneratorToString.Emit(OpCodes.Box, generics[i]);
ilgeneratorToString.Emit(OpCodes.Callvirt, StringBuilderAppendObject);
ilgeneratorToString.Emit(OpCodes.Pop);
}


// .ctor
ilgeneratorConstructor.Emit(OpCodes.Ret);


// Equals()
if (names.Length == 0)
{
ilgeneratorEquals.Emit(OpCodes.Ldnull);
ilgeneratorEquals.Emit(OpCodes.Ceq);
ilgeneratorEquals.Emit(OpCodes.Ldc_I4_0);
ilgeneratorEquals.Emit(OpCodes.Ceq);
}
else
{
ilgeneratorEquals.Emit(OpCodes.Ret);
ilgeneratorEquals.MarkLabel(equalsLabel);
ilgeneratorEquals.Emit(OpCodes.Ldc_I4_0);
}


ilgeneratorEquals.Emit(OpCodes.Ret);


// GetHashCode()
ilgeneratorGetHashCode.Emit(OpCodes.Stloc_0);
ilgeneratorGetHashCode.Emit(OpCodes.Ldloc_0);
ilgeneratorGetHashCode.Emit(OpCodes.Ret);


// ToString()
ilgeneratorToString.Emit(OpCodes.Ldloc_0);
ilgeneratorToString.Emit(OpCodes.Ldstr, names.Length == 0 ? "{ }" : " }");
ilgeneratorToString.Emit(OpCodes.Callvirt, StringBuilderAppendString);
ilgeneratorToString.Emit(OpCodes.Pop);
ilgeneratorToString.Emit(OpCodes.Ldloc_0);
ilgeneratorToString.Emit(OpCodes.Callvirt, ObjectToString);
ilgeneratorToString.Emit(OpCodes.Ret);


type = tb.CreateType();


type = GeneratedTypes.GetOrAdd(fullName, type);
}
}
}


if (types.Length != 0)
{
type = type.MakeGenericType(types);
}


return type;
}


private static string Escape(string str)
{
// We escape the \ with \\, so that we can safely escape the
// "|" (that we use as a separator) with "\|"
str = str.Replace(@"\", @"\\");
str = str.Replace(@"|", @"\|");
return str;
}
}

Reference: https://stackoverflow.com/a/29428640/2073920

小开

Slightly more modular version of svick's answer, using a couple extension methods:

public static class Extensions
{
public static void AddRange<T>(this ICollection<T> collection, IEnumerable<T> items)
{
foreach (var item in items)
{
collection.Add(item);
}
}


public static dynamic ToDynamicObject(this IDictionary<string, object> source)
{
ICollection<KeyValuePair<string, object>> someObject = new ExpandoObject();
someObject.AddRange(source);
return someObject;
}
}

小开

I tried to do this in one statement with a reduce function (Aggregate in Linq). The code below does the same as the accepted answer:

var dict = new Dictionary<string, object> { { "Property", "foo" } };
dynamic eo = dict.Aggregate(new ExpandoObject() as IDictionary<string, Object>,
(a, p) => { a.Add(p); return a; });
string value = eo.Property;

小开

The credit here goes to the accepted answer. Adding this because I wanted to turn a List< Dictionary< string,object >> into a List< dynamic>. The purpose is for pulling records from a database table. Here is what I did.

    public static List<dynamic> ListDictionaryToListDynamic(List<Dictionary<string,object>> dbRecords)
{
var eRecords = new List<dynamic>();
foreach (var record in dbRecords)
{
var eRecord = new ExpandoObject() as IDictionary<string, object>;
foreach (var kvp in record)
{
eRecord.Add(kvp);
}
eRecords.Add(eRecord);
}
return eRecords;
}

小开

The code below handles sub-dictionaries and converts them to the nested dynamic objects as well:

[return: NotNullIfNotNull("dictionary")]
static dynamic? ToDynamic(IReadOnlyDictionary<string, object?>? dictionary) =>
dictionary?.Aggregate(
(IDictionary<string, object?>)new ExpandoObject(),
(obj, i) =>
{
if (i.Value is IReadOnlyDictionary<string, object?> nestedDictionary)
obj.Add(new(i.Key, ToDynamic(nestedDictionary)));
else
obj.Add(i);
return obj;
});

This approach allows to access the contents of nested dictionaries just by accessing the dynamic object itself:

var record = ToDynamic(...);
string cityName = record.city.name;