首先，使事情更清楚，我会从上面解释我的情况：转换词典<string，object>转为匿名对象？
我有具有以下签名的方法：
public virtual void SendEmail(String from, List<String> recepients, Object model)
我想要做的是产生一个匿名对象它具有模型对象的属性以及前两个参数。将模型对象平铺到PropertyInfo []中非常简单。因此，我想创建一个字典，它将持有PropertyInfo和前两个参数，然后转换为匿名对象，其中键是属性的名称，值是该属性的实际值。
这可能吗？还有其他建议吗？
如果你真的想字典转换为具有字典为属性的项目对象，你可以使用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;
但我不知道如何做的是要帮助您。
匿名对象是由编译器为您生成的对象。您无法动态创建一个。另一方面，你可以发出这样的对象，但我真的不认为这是个好主意。
可能你可以尝试动态对象吗？结果将是一个包含所有你需要的属性的对象。
是一个动态的对象将是完美的。谨慎提供一个例子？ – Kassem
我不认为这是一个准确的陈述，你甚至可以在运行时创建真正的CLR类型，我无法想象为什么你不能在运行时创建一个匿名类型。 –
@ChrisMarisic回答“你可以发出这样的对象”。你当然可以。 –
如果您想要隐蔽字典太一类，你可以使用下面的字典转换为该类的对象：
Example类：
public class Properties1
{
public string Property { get; set; }
}
解决方案：
JavaScriptSerializer serializer = new JavaScriptSerializer();
Dictionary<string, object> dict = new Dictionary<string, object> { { "Property", "foo" } };
Properties1 properties = serializer.ConvertToType<Properties1>(dict);
string value = properties.Property;
你也可以用这样的方法来构建从dicti对象onary，显然这也需要你有一堂课。
private static dynamic DictionaryToObject(Dictionary<string, object> dict)
{
IDictionary<string, object> eo = new ExpandoObject() as IDictionary<string, object>;
foreach (KeyValuePair<string, object> kvp in dict)
{
eo.Add(kvp);
}
return eo;
}
您可以使用它像这样：
Dictionary<string, object> dict = new Dictionary<string, object> {{ "Property", "foo" }};
dynamic properties = DictionaryToObject(dict);
string value = properties.Property;
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;
}
但是，如果你没有这个类，你可以从这样的字典创建一个动态对象
如果您想将Dictionary<string, object>转换为匿名System.Object。您可以使用此方法：
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;
}
这样的：
var dict = new Dictionary<string, string>
{
{"Id", "1"},
{"Title", "My title"},
{"Description", "Blah blah blah"},
};
object obj1 = FromDictToAnonymousObj(dict);
获得你的对象。 凡AnonymousType类代码：
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;
}
}
svick的回答稍微更模块化的版本，使用一对夫妇的扩展方法：
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;
}
}
我喜欢这个主意。但是，没有'ICollection.AddRange'。你必须通过使用扩展来提供AddRange，或者尝试使用'source.ToList（）。ForEach（someObject.Add）' – Nils
哎呀，很好！我习惯了我认为理所当然的扩展方法。将更新答案。 –
我试图做到这一点的一个声明具有reduce函数（Linq中的聚合）。下面的代码与接受的答案相同：
var dict = new Dictionary<string, object> { { "Property", "foo" } };
dynamic eo = dict.Aggregate(new ExpandoObject() as IDictionary<string, Object>,
(a, p) => { a.Add(p.Key, p.Value); return a; });
string value = eo.Property;
你想这么做的原因是什么？ –
我怀疑你可以轻松地支持任意一组键值 - 你必须在运行时动态构建一个具有这些属性的新类型。既然你只是要读回他们，你最好创建一个也接受你的字典的重载。 – Rup
@Rup：其实，这也是一个合理的选择。我已经找到了一个适合我的需求的快捷方式，但我仍然想知道上面的问题的答案......只是出于好奇:) – Kassem