I'm trying to make a simple HtmlHelper to create a EditorFor that deal with List<T> index childs.
I did some like this
public static IHtmlString EditorFor<TModel, TValue>(this HtmlHelper<TModel> htmlHelper
, Expression<Func<TModel, TValue>> exp
, Expression<Func<TModel, int>> expId
, object htmlAttributes = null)
{
//Id value
var id = expId.Compile().Invoke(htmlHelper.ViewData.Model);
//Prefix
var prefix = htmlHelper.ViewData.TemplateInfo.HtmlFieldPrefix;
//Propertyname
var propertyName = ExpressionHelper.GetExpressionText(exp);
//Create id and name for the EditorFor
var htmlId = $"{prefix}_{id}__{propertyName}";
var htmlName = $"{prefix}[{id}].{propertyName}";
//Create the must have attributes.
var attributes = new
RouteValueDictionary(
new {
id = htmlId,
#Name = htmlName
});
//if htmlAttributes paramter has values, will merge
if(htmlAttributes != null){
//merge..
foreach (var attr in new RouteValueDictionary(htmlAttributes).Where(attr => !attributes.ContainsKey(attr.Key)))
{
attributes.Add(attr.Key,attr.Value);
}
}
//Create a editor for
var editor = htmlHelper.EditorFor(exp, new
{
htmlAttributes = attributes
});
return new HtmlString(editor.ToString());
}
In the view i'm using it like
#Html.EditorFor(x => x.GradienteDeEntrada, x => x.Id)
My problem here, is that the Html markup generated is
<input count="2" keys="System.Collections.Generic.Dictionary`2+KeyCollection[System.String,System.Object]" values="System.Collections.Generic.Dictionary`2+ValueCollection[System.String,System.Object]" autocomplete="off" class=" decimal" data-val="true" data-val-number="El campo Gradiente de entrada debe ser un número." id="DatosTermicos_GradienteEntrada" name="DatosTermicos.GradienteEntrada" type="text" value="">
I try converting it to HtmlHelper with this answer or dynamic with this other but when i use any of this methods, both Id and Name are just ignored.
If I create the htmlAttributes as a object
var attributes = new { id = htmlId, #Name = htmlName };
work just fine, the problem is that I don't know how to merge it with the received parameters. How can I pass the RouteValueDictionary with my HtmlAttributes to the EditorFor?
I solve it using this answer from Abdul Rauf based on converting the RouteValueDictionary in Anonymous Object (System.Object) instead of dynamic.
This is the 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;
}
The AnonymousType class code :
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;
}
}
Related
I did write a model generator to create an interface between client ViewModels and server Models.
Some model classes are serialize with [JsonObject(MemberSerialization.OptIn)] attribute and their properties are marked with [JsonProperty ...] to be serialized, in addition i have some custom attributes which need to be handled in my custom DefaultContractResolver.
Here is how I create my ModelView from any source type
public Type CreateModelView(Type sourceType) {
...
foreach (var attribute in sourceType.CustomAttributes)
typeBuilder.SetCustomAttribute(
new CustomAttributeBuilder(
attribute.Constructor,
attribute.ConstructorArguments.Select(x => x.Value).ToArray()));
...
var fields = GetFields(sourceType);
foreach (var field in fields)
CreateProperty(typeBuilder, field.Name, field.PropertyType, field.GetCustomAttributes(true));
return typeBuilder.CreateTypeInfo().AsType();
}
private void CreateProperty(TypeBuilder typeBuilder, string name, Type type, object[] customAttributes)
{
var fieldBuilder = typeBuilder.DefineField(name, type, FieldAttributes.Public);
var propertyBuilder = typeBuilder.DefineProperty(name, PropertyAttributes.HasDefault, type, null);
var GetMethodBuilder = typeBuilder.DefineMethod(
"Get" + name,
MethodAttributes.Public |
MethodAttributes.SpecialName |
MethodAttributes.HideBySig, type,
Type.EmptyTypes);
var iLGenerator = GetMethodBuilder.GetILGenerator();
iLGenerator.Emit(OpCodes.Ldarg_0);
iLGenerator.Emit(OpCodes.Ldfld, fieldBuilder);
iLGenerator.Emit(OpCodes.Ret);
var SetMethodBuilder =
typeBuilder.DefineMethod("Set" + name,
MethodAttributes.Public |
MethodAttributes.SpecialName |
MethodAttributes.HideBySig,
null,
new[] { type });
ILGenerator setIl = SetMethodBuilder.GetILGenerator();
Label modifyProperty = setIl.DefineLabel();
Label exitSet = setIl.DefineLabel();
setIl.MarkLabel(modifyProperty);
setIl.Emit(OpCodes.Ldarg_0);
setIl.Emit(OpCodes.Ldarg_1);
setIl.Emit(OpCodes.Stfld, fieldBuilder);
setIl.Emit(OpCodes.Nop);
setIl.MarkLabel(exitSet);
setIl.Emit(OpCodes.Ret);
foreach (var customAttribute in customAttributes)
AddCustomAttributeToProperty(customAttribute, propertyBuilder);
propertyBuilder.SetGetMethod(GetMethodBuilder);
propertyBuilder.SetSetMethod(SetMethodBuilder);
}
/// <summary>
/// Given a custom attribute and property builder, adds an instance of custom attribute
/// to the property builder
/// </summary>
void AddCustomAttributeToProperty(object customAttribute, PropertyBuilder propBuilder)
{
var customAttributeBuilder = BuildCustomAttribute(customAttribute);
if (customAttributeBuilder != null)
{
propBuilder.SetCustomAttribute(customAttributeBuilder);
}
}
static CustomAttributeBuilder BuildCustomAttribute(object customAttribute)
{
ConstructorInfo longestCtor = null;
// Get constructor with the largest number of parameters
foreach (var cInfo in customAttribute.GetType().GetConstructors().
Where(cInfo => longestCtor == null || longestCtor.GetParameters().Length < cInfo.GetParameters().Length))
longestCtor = cInfo;
if (longestCtor == null)
{
return null;
}
// For each constructor parameter, get corresponding (by name similarity) property and get its value
var args = new object[longestCtor.GetParameters().Length];
var position = 0;
foreach (var consParamInfo in longestCtor.GetParameters())
{
var attrPropInfo = customAttribute.GetType().GetProperty(consParamInfo.Name, BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);
if (attrPropInfo != null)
{
args[position] = attrPropInfo.GetValue(customAttribute, null);
}
else
{
args[position] = null;
var attrFieldInfo = customAttribute.GetType().GetField(consParamInfo.Name, BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.IgnoreCase);
if (attrFieldInfo == null)
{
if (consParamInfo.ParameterType.IsValueType)
{
args[position] = Activator.CreateInstance(consParamInfo.ParameterType);
}
}
else
{
args[position] = attrFieldInfo.GetValue(customAttribute);
}
}
++position;
}
var propList = new List<PropertyInfo>();
var propValueList = new List<object>();
foreach (var attrPropInfo in customAttribute.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance))
{
if (!attrPropInfo.CanWrite)
{
continue;
}
object defaultValue = null;
var defaultAttributes = attrPropInfo.GetCustomAttributes(typeof(DefaultValueAttribute), true);
if (defaultAttributes.Length > 0)
{
defaultValue = ((DefaultValueAttribute)defaultAttributes[0]).Value;
}
var value = attrPropInfo.GetValue(customAttribute, null);
if (value == defaultValue)
{
continue;
}
propList.Add(attrPropInfo);
propValueList.Add(value);
}
return new CustomAttributeBuilder(longestCtor, args, propList.ToArray(), propValueList.ToArray());
}
i tested this code as well with field.CustomAttributes and result was same.
propertyBuilder.SetCustomAttribute(
new CustomAttributeBuilder(
attribute.Constructor,
attribute.ConstructorArguments.Select(x => x.Value).ToArray()));
and the problem is here in ContractResolver when the result of attributes is empty,
public class ContractResolver : DefaultContractResolver {
...
protected override IList<JsonProperty> CreateProperties(
Type type,
MemberSerialization memberSerialization)
{
var propertyList = base.CreateProperties(type, memberSerialization);
foreach (var jProperty in propertyList)
{
var attributes = jProperty.AttributeProvider.GetAttributes(true);
var isBindNever = attributes.OfType<BindNeverAttribute>().Any();
var isKey = attributes.OfType<KeyAttribute>().Any();
...
}
and [JsonProperty ...] attributes are not working as well.
P.S. I can get custom attributes from this code
var PropertyType = jProperty.DeclaringType.GetProperties()
.Where(property => property.Name.ToLower() == jProperty.PropertyName.ToLower())
.FirstOrDefault();
The problem is why is jProperty.AttributeProvider.GetAttributes not working as expected,
Why [JsonProperty] not working as expected (marked properties won't serialized).
This will solve problem, however it's not efficient
public class JsonResolver : DefaultContractResolver
{
...
protected override List<MemberInfo> GetSerializableMembers(Type objectType)
{
var serializableMembers = base.GetSerializableMembers(objectType).Select(memberInfo => memberInfo.Name);
return objectType.GetProperties().Where(memberInfo => serializableMembers.Contains(memberInfo.Name)).Cast<MemberInfo>().ToList();
}
...
}
I am trying to create a c# class dynamically at run time.
using System;
class Hist
{
private int? _min;
private int? _max;
public int? min
{
get{return _min;}
set {_min = value;}
}
public int? max
{
get{return _max;}
set {_max = value;}
}
}
public class ProcessData
{
private string _id;
private string _source;
private int? _currentValue;
private Hist _hist;
public Hist hist
{
get { return _hist; }
set{ _hist = value; }
}
public string id
{
get {return _id;}
set { _id = value; }
}
public string source
{
get {return _source;}
set { _source = value; }
}
public int? currentValue
{
get {return _currentValue;}
set { _currentValue = value; }
}
public int? min
{
get { return (hist != null) ? hist.min : null; }
}
public int? max
{
get { return (hist != null) ? hist.max : null; }
}
}
But i am unable to do this specifically.
return (hist != null) ? hist.max : null;
i just need is the get method for any of the min or max property of ProcessData class.
My code for above task:
var method = parentType.GetMethod("get_" + propertyName);
getPropMthdBldr = tb.DefineMethod("get_" + propertyName,
MethodAttributes.Public |
MethodAttributes.SpecialName |
MethodAttributes.HideBySig,
propertyType, Type.EmptyTypes);
getIl = getPropMthdBldr.GetILGenerator();
var moveTo = getIl.DefineLabel();
getIl.Emit(OpCodes.Ldarg_0);
getIl.EmitCall(OpCodes.Call, parentGetMethod, Type.EmptyTypes);
getIl.Emit(OpCodes.Brtrue_S, moveTo);
getIl.Emit(OpCodes.Ldloca_S, 0);
getIl.Emit(OpCodes.Initobj, typeof(int?));
getIl.Emit(OpCodes.Ldloc_0);
getIl.Emit(OpCodes.Ret);
getIl.MarkLabel(moveTo);
getIl.Emit(OpCodes.Ldarg_0);
getIl.EmitCall(OpCodes.Call, parentGetMethod,Type.EmptyTypes);
getIl.EmitCall(OpCodes.Callvirt, method,Type.EmptyTypes);
getIl.Emit(OpCodes.Ret);
Problem is that you are trying to use local variable that not declared:
getIl.Emit(OpCodes.Ldloca_S, 0); // load address of local variable with index 0 on stack
getIl.Emit(OpCodes.Initobj, typeof(int?)); // initialize local variable
getIl.Emit(OpCodes.Ldloc_0); // load value of local variable with index 0 on stack
You can define required local variable like this:
var local = getIl.DeclareLocal(typeof(int?));
And your code will be valid, but to improve readability I would advise you to use variable local instead index. It could be done like this:
getIl.Emit(OpCodes.Ldloca_S, local); // load address of local variable on stack
getIl.Emit(OpCodes.Initobj, typeof(int?)); // initialize local variable
getIl.Emit(OpCodes.Ldloc, local); // load value of local variable on stack
P.S. I'll put here code that I've used for generation of classes Hist and ProcessData, may be it could be useful for you in some way, in case if my explanation was not sufficient.
Main logic in this helper for property creation:
public static class TypeBuilderExtensions
{
public static PropertyBuilder CreateProperty<T>(this TypeBuilder builder, string name) => CreateProperty(builder, typeof(T), name);
public static PropertyBuilder CreateProperty(this TypeBuilder builder, Type propertyType, string name)
{
var field = builder.DefineField($"_{name}", propertyType, FieldAttributes.Private);
var getMethodBuilder = builder.DefineMethod($"get_{name}", MethodAttributes.Public, propertyType, Type.EmptyTypes);
var getGenerator = getMethodBuilder.GetILGenerator();
getGenerator.Emit(OpCodes.Ldarg_0);
getGenerator.Emit(OpCodes.Ldfld, field);
getGenerator.Emit(OpCodes.Ret);
var setMethodBuilder = builder.DefineMethod($"set_{name}", MethodAttributes.Public, typeof(void), new[] { propertyType });
var setGenerator = setMethodBuilder.GetILGenerator();
setGenerator.Emit(OpCodes.Ldarg_0);
setGenerator.Emit(OpCodes.Ldarg_1);
setGenerator.Emit(OpCodes.Stfld, field);
setGenerator.Emit(OpCodes.Ret);
var propertyBuilder = builder.DefineProperty(name, PropertyAttributes.None, propertyType, Type.EmptyTypes);
propertyBuilder.SetGetMethod(getMethodBuilder);
propertyBuilder.SetSetMethod(setMethodBuilder);
return propertyBuilder;
}
public static PropertyBuilder CreateCalculatedProperty<T>(this TypeBuilder builder, string name, MethodInfo getObject, MethodInfo getObjectProperty) => CreateCalculatedProperty(builder, typeof(T), name, getObject, getObjectProperty);
public static PropertyBuilder CreateCalculatedProperty(this TypeBuilder builder, Type propertyType, string name, MethodInfo getObject, MethodInfo getObjectProperty)
{
var getMethodBuilder = builder.DefineMethod($"get_{name}", MethodAttributes.Public, propertyType, Type.EmptyTypes);
var getGenerator = getMethodBuilder.GetILGenerator();
var label = getGenerator.DefineLabel();
var local = getGenerator.DeclareLocal(propertyType);
getGenerator.Emit(OpCodes.Ldarg_0);
getGenerator.Emit(OpCodes.Callvirt, getObject);
getGenerator.Emit(OpCodes.Brtrue, label);
getGenerator.Emit(OpCodes.Ldloca_S, local);
getGenerator.Emit(OpCodes.Initobj, propertyType);
getGenerator.Emit(OpCodes.Ldloc, local);
getGenerator.Emit(OpCodes.Ret);
getGenerator.MarkLabel(label);
getGenerator.Emit(OpCodes.Ldarg_0);
getGenerator.Emit(OpCodes.Callvirt, getObject);
getGenerator.Emit(OpCodes.Callvirt, getObjectProperty);
getGenerator.Emit(OpCodes.Ret);
var propertyBuilder = builder.DefineProperty(name, PropertyAttributes.None, propertyType, Type.EmptyTypes);
propertyBuilder.SetGetMethod(getMethodBuilder);
return propertyBuilder;
}
}
Here is class creation itself:
var assemblyBuilder = AssemblyBuilder.DefineDynamicAssembly(new AssemblyName("TestAssembly"), AssemblyBuilderAccess.Run);
var moduleBuilder = assemblyBuilder.DefineDynamicModule("TestModule");
var histBuilder = moduleBuilder.DefineType("Hist");
var minProperty = histBuilder.CreateProperty<int?>("min");
var maxProperty = histBuilder.CreateProperty<int?>("max");
var processDataBuilder = moduleBuilder.DefineType("ProcessData");
var histProperty = processDataBuilder.CreateProperty(histBuilder, "hist");
processDataBuilder.CreateProperty<string>("id");
processDataBuilder.CreateProperty<string>("source");
processDataBuilder.CreateProperty<int?>("currentValue");
processDataBuilder.CreateCalculatedProperty<int?>("min", histProperty.GetMethod, minProperty.GetMethod);
processDataBuilder.CreateCalculatedProperty<int?>("max", histProperty.GetMethod, maxProperty.GetMethod);
And finally primitive validation of created classes:
void ValidateProperty(object instance, string name, object value, bool setValue = true)
{
var type = instance.GetType();
var property = type.GetProperty(name);
if (setValue) property.SetValue(instance, value);
var result = property.GetValue(instance);
var equals = property.PropertyType.IsValueType && value != null ? value.Equals(result) : value == result;
if (!equals)
throw new InvalidDataException("Property not valid");
}
var histType = histBuilder.CreateType();
var histInstance = Activator.CreateInstance(histType);
ValidateProperty(histInstance, "min", 12);
ValidateProperty(histInstance, "max", 21);
var processDataType = processDataBuilder.CreateType();
var processDataInstance = Activator.CreateInstance(processDataType);
ValidateProperty(processDataInstance, "hist", histInstance);
ValidateProperty(processDataInstance, "id", "Test!");
ValidateProperty(processDataInstance, "source", "Source#");
ValidateProperty(processDataInstance, "currentValue", 126);
ValidateProperty(processDataInstance, "min", 12, false);
ValidateProperty(processDataInstance, "max", 21, false);
ValidateProperty(processDataInstance, "hist", null);
ValidateProperty(processDataInstance, "min", null, false);
ValidateProperty(processDataInstance, "max", null, false);
Im trying to create a Proxy Class from an interface. In the methods I just want to collect all arguments in an object array and pass on to a known method. So faar I have managed to get it working without params and with return types. As soon as I try to create my array I get "Additional information: Common Language Runtime detected an invalid program.".. Dont really know how to debug from here and the IL codes seems to be correct ( ? ).
public class Program
{
static void Main(string[] args)
{
var v = CreateProxy<IFoo>();
v.DoSomething();
}
public static void TheMethod(object[] args)
{
}
public interface IFoo
{
void DoSomething();
}
public static T CreateProxy<T>()
{
var interfaceType = typeof(T);
AssemblyName assemblyName = new AssemblyName(string.Format("tmp_{0}", interfaceType.FullName));
string moduleName = string.Format("{0}.dll", assemblyName.Name);
string ns = interfaceType.Namespace;
if (!string.IsNullOrEmpty(ns))
ns += ".";
var assembly = AppDomain.CurrentDomain.DefineDynamicAssembly(assemblyName,AssemblyBuilderAccess.RunAndSave);
var module = assembly.DefineDynamicModule(moduleName, false);
var type = module.DefineType(String.Format("{0}Proxy_{1}", ns, interfaceType.Name), TypeAttributes.Class | TypeAttributes.AnsiClass |TypeAttributes.Sealed |TypeAttributes.NotPublic);
type.AddInterfaceImplementation(interfaceType);
//Constructor
var ctor = type.DefineConstructor(MethodAttributes.Public, CallingConventions.HasThis, new Type[] {});
var generator = ctor.GetILGenerator();
generator.Emit(OpCodes.Ret);
//Methods
foreach (var method in interfaceType.GetMethods())
{
var args = method.GetParameters();
var methodImpl = type.DefineMethod(method.Name, MethodAttributes.Public | MethodAttributes.Virtual, method.ReturnType, (from arg in args select arg.ParameterType).ToArray());
generator = methodImpl.GetILGenerator();
generator.Emit(OpCodes.Nop);
generator.Emit(OpCodes.Ldc_I4_1);
generator.Emit(OpCodes.Newarr, typeof(object));
generator.Emit(OpCodes.Stloc_0);
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Call, typeof(Program).GetMethod(nameof(Program.TheMethod)));
generator.Emit(OpCodes.Nop);
generator.Emit(OpCodes.Ret);
}
return (T)Activator.CreateInstance(type.CreateType());
}
}
The method im trying to Emit should look like this.
public void DoSomething()
{
object[] arr = new object[1];
Program.TheMethod(arr);
}
What am I missing here ?
You should initialize locals:
foreach (var method in interfaceType.GetMethods())
{
var args = method.GetParameters();
var methodImpl = type.DefineMethod(method.Name, MethodAttributes.Public | MethodAttributes.Virtual, method.ReturnType, (from arg in args select arg.ParameterType).ToArray());
generator = methodImpl.GetILGenerator();
generator.DeclareLocal(typeof(object[]));
....
....
I'm trying to use LINQ expression trees to initialize a new anonymous object with a subset of fields from a passed-in object. The subset of fields will typically be a single property but could be more (4 or so).
An example:
void DoWork(Type t)
{
//do some work to figure out which properties I want to use
List<PropertyInfo>() props = (from p in t.GetProperties()
where p.HasAttribute(MyAttribute)
select p).ToList();
//now I want to create a lambda expression that's like:
// (x=> new {x.Prop1, x.Prop2, ...})
//for each property in the list props
//create parameter
var param = Expression.Parameter(t,"t");
//get list of expressions for properties
var initValues = (from p in props
select Expression.PropertyOrField(param, p.Name)
).ToList();
//build expression body
Expression body = Expression. //<<<< I have no idea what to do here
//create lambda
dynamic propLambda = Expression.Lambda(body, param);
//use it! MyFunction( x=> new {x.Prop1, x.Prop2,...});
MyFunction(lambda);
}
The bad news: Since you're gonna build the anonymous type dynamically at runtime, it doesn't exist at compile time, as it would if the compiler encountered a new {...} in your code. There's no way around Reflection.Emit, which isn't tivial.
The good news: I've already done it, because I had the same needs. Used ILDASM to see what the compiler generates and mimic that as closely as possible.
So without further ado:
/// <summary>
/// Creates types that are much like anonymous types.
/// </summary>
public static class TupleFactory
{
// the dynamic module used to emit new types
private static readonly ModuleBuilder _module = AppDomain.CurrentDomain.DefineDynamicAssembly(new AssemblyName { Name = nameof(TupleFactory) }, AssemblyBuilderAccess.Run).DefineDynamicModule(nameof(TupleFactory), false);
// the generic type definitions constructed so far
private static readonly Dictionary<ICollection<string>, Type> _genericTypeDefinitions = new Dictionary<ICollection<string>, Type>(CollectionComparer<string>.Default);
// the new expression factory singletons constructed so far
private static readonly Dictionary<ICollection<KeyValuePair<string, Type>>, ITupleFactory> _newExpressionFactories = new Dictionary<ICollection<KeyValuePair<string, Type>>, ITupleFactory>(new CollectionComparer<KeyValuePair<string, Type>>(KeyValueComparer<string, Type>.Default));
// some reflection objects used
private static readonly ConstructorInfo _objectCtor = typeof(object).GetConstructor(Type.EmptyTypes);
private static readonly MethodInfo _objectEquals = typeof(object).GetMethod("Equals", BindingFlags.Public | BindingFlags.Instance, null, new[] { typeof(object) }, null);
private static readonly MethodInfo _objectGetHashCode = typeof(object).GetMethod("GetHashCode", BindingFlags.Public | BindingFlags.Instance, null, Type.EmptyTypes, null);
private static readonly MethodInfo _objectToString = typeof(object).GetMethod("ToString", BindingFlags.Public | BindingFlags.Instance, null, Type.EmptyTypes, null);
private static readonly MethodInfo _stringFormat = typeof(string).GetMethod("Format", BindingFlags.Public | BindingFlags.Static, null, new[] { typeof(string), typeof(object[]) }, null);
private static readonly MethodInfo _equalityComparerDefaultGetter;
private static readonly MethodInfo _equalityComparerEquals;
private static readonly MethodInfo _equalityComparerGetHashCode;
static TupleFactory()
{
// init more reflection objects
_equalityComparerDefaultGetter = typeof(EqualityComparer<>).GetProperty("Default", BindingFlags.Public | BindingFlags.Static).GetGetMethod();
var eqT = typeof(EqualityComparer<>).GetGenericArguments()[0];
_equalityComparerEquals = typeof(EqualityComparer<>).GetMethod("Equals", BindingFlags.Public | BindingFlags.Instance, null, new[] { eqT, eqT }, null);
_equalityComparerGetHashCode = typeof(EqualityComparer<>).GetMethod("GetHashCode", BindingFlags.Public | BindingFlags.Instance, null, new[] { eqT }, null);
}
/// <summary>
/// Gets a <see cref="ITupleFactory"/> singleton for a sequence of properties.
/// </summary>
/// <param name="properties">Name/Type pairs for the properties.</param>
public static ITupleFactory Create(IEnumerable<KeyValuePair<string, Type>> properties)
{
// check input
if (properties == null) throw new ArgumentNullException(nameof(properties));
var propList = properties.ToList();
if (propList.Select(p => p.Key).Distinct().Count() != propList.Count)
throw new ArgumentException("Property names must be distinct.");
lock (_module) // locks access to the static dictionaries
{
ITupleFactory result;
if (_newExpressionFactories.TryGetValue(propList, out result)) // we already have it
return result;
var propertyNames = propList.Select(p => p.Key).ToList();
Type genericTypeDefinition;
if (!_genericTypeDefinitions.TryGetValue(propertyNames, out genericTypeDefinition))
{
#region create new generic type definition
{
var typeBuilder = _module.DefineType($"<>f__AnonymousType{_newExpressionFactories.Count}`{propertyNames.Count}", TypeAttributes.Public | TypeAttributes.AutoClass | TypeAttributes.AnsiClass | TypeAttributes.Sealed | TypeAttributes.BeforeFieldInit);
var genParams = propertyNames.Count > 0
? typeBuilder.DefineGenericParameters(propertyNames.Select(p => $"<{p}>j__TPar").ToArray())
: new GenericTypeParameterBuilder[0];
// attributes on type
var debuggerDisplay = "\\{ " + string.Join(", ", propertyNames.Select(n => $"{n} = {{{n}}}")) + " }";
// ReSharper disable AssignNullToNotNullAttribute
typeBuilder.SetCustomAttribute(new CustomAttributeBuilder(typeof(DebuggerDisplayAttribute).GetConstructor(new[] { typeof(string) }), new object[] { debuggerDisplay }));
typeBuilder.SetCustomAttribute(new CustomAttributeBuilder(typeof(CompilerGeneratedAttribute).GetConstructor(Type.EmptyTypes), new object[0]));
// ReSharper restore AssignNullToNotNullAttribute
var fields = new List<FieldBuilder>();
var props = new List<PropertyBuilder>();
foreach (var name in propertyNames)
{
var genParam = genParams[fields.Count];
var field = typeBuilder.DefineField($"<{name}>i__Field", genParam, FieldAttributes.Private | FieldAttributes.InitOnly);
fields.Add(field);
var property = typeBuilder.DefineProperty(name, PropertyAttributes.None, genParam, null);
props.Add(property);
var getter = typeBuilder.DefineMethod($"get_{name}", MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.HideBySig, genParam, Type.EmptyTypes);
var il = getter.GetILGenerator();
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, field);
il.Emit(OpCodes.Ret);
property.SetGetMethod(getter);
}
#region ctor
{
// ReSharper disable once CoVariantArrayConversion
var ctorBuilder = typeBuilder.DefineConstructor(MethodAttributes.Public, CallingConventions.Standard, genParams);
var il = ctorBuilder.GetILGenerator();
// call base class ctor
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Call, _objectCtor);
// assign args to fields
for (var i = 0; i < fields.Count; i++)
{
il.Emit(OpCodes.Ldarg_0);
EmitLdarg(il, i + 1);
il.Emit(OpCodes.Stfld, fields[i]);
}
il.Emit(OpCodes.Ret);
}
#endregion
#region override Equals
{
var equals = typeBuilder.DefineMethod("Equals", MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual, typeof(bool), new[] { typeof(object) });
typeBuilder.DefineMethodOverride(equals, _objectEquals);
var il = equals.GetILGenerator();
il.DeclareLocal(typeBuilder);
var retFalse = il.DefineLabel();
var ret = il.DefineLabel();
// local = argument as (the type being constructed)?
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Isinst, typeBuilder);
il.Emit(OpCodes.Stloc_0);
// push result of the "as" operator
il.Emit(OpCodes.Ldloc_0);
foreach (var field in fields)
{
var comparer = typeof(EqualityComparer<>).MakeGenericType(field.FieldType);
var defaultGetter = TypeBuilder.GetMethod(comparer, _equalityComparerDefaultGetter);
var equalsMethod = TypeBuilder.GetMethod(comparer, _equalityComparerEquals);
// check if the result of the previous check is false
il.Emit(OpCodes.Brfalse, retFalse);
// push EqualityComparer<FieldType>.Default.Equals(this.field, other.field)
il.Emit(OpCodes.Call, defaultGetter);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, field);
il.Emit(OpCodes.Ldloc_0);
il.Emit(OpCodes.Ldfld, field);
il.Emit(OpCodes.Callvirt, equalsMethod);
}
// jump to the end with what was the last result
il.Emit(OpCodes.Br_S, ret);
// push false
il.MarkLabel(retFalse);
il.Emit(OpCodes.Ldc_I4_0);
il.MarkLabel(ret);
il.Emit(OpCodes.Ret);
}
#endregion
#region override GetHashCode
{
var getHashCode = typeBuilder.DefineMethod("GetHashCode", MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual, typeof(int), Type.EmptyTypes);
typeBuilder.DefineMethodOverride(getHashCode, _objectGetHashCode);
var il = getHashCode.GetILGenerator();
// init result with seed
il.Emit(OpCodes.Ldc_I4, HashCode.Seed);
foreach (var field in fields)
{
var comparer = typeof(EqualityComparer<>).MakeGenericType(field.FieldType);
var defaultGetter = TypeBuilder.GetMethod(comparer, _equalityComparerDefaultGetter);
var getHashCodeMethod = TypeBuilder.GetMethod(comparer, _equalityComparerGetHashCode);
// hash so far * factor
il.Emit(OpCodes.Ldc_I4, HashCode.Factor);
il.Emit(OpCodes.Mul);
// ... + EqualityComparer<FieldType>.GetHashCode(field)
il.Emit(OpCodes.Call, defaultGetter);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, field);
il.Emit(OpCodes.Callvirt, getHashCodeMethod);
il.Emit(OpCodes.Add);
}
il.Emit(OpCodes.Ret);
}
#endregion
#region override ToString
{
var toString = typeBuilder.DefineMethod("ToString", MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual, typeof(string), Type.EmptyTypes);
typeBuilder.DefineMethodOverride(toString, _objectToString);
var template = "{{ " + string.Join(", ", propertyNames.Select((n, i) => $"{n} = {{{i}}}")) + " }}";
var il = toString.GetILGenerator();
// push template
il.Emit(OpCodes.Ldstr, template);
// push new array
EmitLdc(il, fields.Count);
il.Emit(OpCodes.Newarr, typeof(object));
var index = 0;
foreach (var field in fields)
{
il.Emit(OpCodes.Dup); // duplicate array ref
EmitLdc(il, index); // push array index
// store boxed field in array
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, field);
il.Emit(OpCodes.Box, field.FieldType);
il.Emit(OpCodes.Stelem, typeof(object));
index++;
}
il.Emit(OpCodes.Call, _stringFormat);
il.Emit(OpCodes.Ret);
}
#endregion
genericTypeDefinition = typeBuilder.CreateType();
}
#endregion
_genericTypeDefinitions.Add(propertyNames, genericTypeDefinition);
}
var type = propList.Count == 0 ? genericTypeDefinition : genericTypeDefinition.MakeGenericType(propList.Select(p => p.Value).ToArray());
result = new TupleFactoryImpl(type, propertyNames);
_newExpressionFactories.Add(propList, result);
return result;
}
}
/// <summary>
/// Gets a <see cref="NewExpression"/> for a tuple type with the specified properties.
/// </summary>
public static NewExpression MakeNewExpression(IEnumerable<KeyValuePair<string, Expression>> properties)
{
var props = properties.ToList();
var tupleFactory = Create(props.Select(p => new KeyValuePair<string, Type>(p.Key, p.Value.Type)));
return tupleFactory.MakeNewExpression(props.Select(p => p.Value));
}
private sealed class TupleFactoryImpl : ITupleFactory
{
public Type TupleType { get; }
private readonly ConstructorInfo _ctor;
private readonly MemberInfo[] _properties;
public TupleFactoryImpl(Type tupleType, IEnumerable<string> propertyNames)
{
TupleType = tupleType;
_ctor = tupleType.GetConstructors().Single();
var propsByName = tupleType.GetProperties().ToDictionary(p => p.Name);
_properties = propertyNames.Select(name => (MemberInfo)propsByName[name]).ToArray();
}
public NewExpression MakeNewExpression(IEnumerable<Expression> arguments)
{
return Expression.New(_ctor, arguments, _properties);
}
}
/// <summary>
/// Helper function to pick the optimal op code.
/// </summary>
private static void EmitLdarg(ILGenerator il, int index)
{
if (index < 0) throw new ArgumentOutOfRangeException();
switch (index)
{
case 0: il.Emit(OpCodes.Ldarg_0); break;
case 1: il.Emit(OpCodes.Ldarg_1); break;
case 2: il.Emit(OpCodes.Ldarg_2); break;
case 3: il.Emit(OpCodes.Ldarg_3); break;
default:
if (index <= byte.MaxValue)
il.Emit(OpCodes.Ldarg_S, (byte)index);
else if (index <= short.MaxValue)
il.Emit(OpCodes.Ldarg, (short)index);
else
throw new ArgumentOutOfRangeException();
break;
}
}
/// <summary>
/// Helper function to pick the optimal op code.
/// </summary>
private static void EmitLdc(ILGenerator il, int i)
{
switch (i)
{
case -1: il.Emit(OpCodes.Ldc_I4_M1); break;
case 0: il.Emit(OpCodes.Ldc_I4_0); break;
case 1: il.Emit(OpCodes.Ldc_I4_1); break;
case 2: il.Emit(OpCodes.Ldc_I4_2); break;
case 3: il.Emit(OpCodes.Ldc_I4_3); break;
case 4: il.Emit(OpCodes.Ldc_I4_4); break;
case 5: il.Emit(OpCodes.Ldc_I4_5); break;
case 6: il.Emit(OpCodes.Ldc_I4_6); break;
case 7: il.Emit(OpCodes.Ldc_I4_7); break;
case 8: il.Emit(OpCodes.Ldc_I4_8); break;
default:
if (i >= byte.MinValue && i <= byte.MaxValue)
il.Emit(OpCodes.Ldc_I4_S, (byte)i);
else
il.Emit(OpCodes.Ldc_I4, i);
break;
}
}
}
/// <summary>
/// Compute a hash code.
/// </summary>
public struct HashCode
{
// magic numbers for hash code
public const int Seed = 0x20e699b;
public const int Factor = unchecked((int)0xa5555529);
private readonly int? _value;
private HashCode(int value)
{
_value = value;
}
/// <summary>
/// Convert to the actual hash code based on what was added so far.
/// </summary>
public static implicit operator int(HashCode hc) => hc._value ?? 0;
/// <summary>
/// Add a hash code to the state.
/// </summary>
/// <returns>An updated <see cref="HashCode"/>.</returns>
public static HashCode operator +(HashCode hc, int other) => new HashCode(unchecked((hc._value == null ? Seed : hc._value.Value * Factor) + other));
/// <summary>
/// Add a sequence of hash code to the state.
/// </summary>
/// <returns>An updated <see cref="HashCode"/>.</returns>
public static HashCode operator +(HashCode hc, IEnumerable<int> others) => others.Aggregate(hc, (a, c) => a + c);
}
/// <summary>
/// <see cref="IEqualityComparer{T}"/> for <see cref="KeyValuePair{TKey, TValue}"/>.
/// </summary>
public sealed class KeyValueComparer<TKey, TValue> : IEqualityComparer<KeyValuePair<TKey, TValue>>
{
/// <summary>
/// Gets the singleton.
/// </summary>
public static KeyValueComparer<TKey, TValue> Default { get; } = new KeyValueComparer<TKey, TValue>();
private readonly IEqualityComparer<TKey> _keyComparer;
private readonly IEqualityComparer<TValue> _valueComparer;
/// <summary>
/// Initialize by specifying <see cref="IEqualityComparer{T}"/>s for key and value.
/// </summary>
public KeyValueComparer(IEqualityComparer<TKey> keyComparer = null, IEqualityComparer<TValue> valueComparer = null)
{
_keyComparer = keyComparer ?? EqualityComparer<TKey>.Default;
_valueComparer = valueComparer ?? EqualityComparer<TValue>.Default;
}
/// <summary>
/// Equality.
/// </summary>
public bool Equals(KeyValuePair<TKey, TValue> x, KeyValuePair<TKey, TValue> y) => _keyComparer.Equals(x.Key, y.Key) && _valueComparer.Equals(x.Value, y.Value);
/// <summary>
/// Hash code.
/// </summary>
public int GetHashCode(KeyValuePair<TKey, TValue> obj) => new HashCode() + _keyComparer.GetHashCode(obj.Key) + _valueComparer.GetHashCode(obj.Value);
}
/// <summary>
/// <see cref="IEqualityComparer{T}"/> for a collection.
/// </summary>
public sealed class CollectionComparer<TElement> : IEqualityComparer<ICollection<TElement>>
{
/// <summary>
/// Gets an instance using <see cref="EqualityComparer{T}.Default"/> as the element comparer.
/// </summary>
public static CollectionComparer<TElement> Default { get; } = new CollectionComparer<TElement>();
private readonly IEqualityComparer<TElement> _elementComparer;
/// <summary>
/// Initialize with a specific element comparer.
/// </summary>
public CollectionComparer(IEqualityComparer<TElement> elementComparer = null)
{
_elementComparer = elementComparer ?? EqualityComparer<TElement>.Default;
}
/// <summary>
/// Determines whether the specified objects are equal.
/// </summary>
/// <returns>
/// true if the specified objects are equal; otherwise, false.
/// </returns>
public bool Equals(ICollection<TElement> x, ICollection<TElement> y)
{
if (x == null) return y == null;
if (y == null) return false;
return x.Count == y.Count && x.SequenceEqual(y, _elementComparer);
}
/// <summary>
/// Returns a hash code for the specified object.
/// </summary>
/// <returns>
/// A hash code for the specified object.
/// </returns>
/// <param name="obj">The <see cref="T:System.Object"/> for which a hash code is to be returned.</param>
public int GetHashCode(ICollection<TElement> obj)
{
var result = new HashCode() + typeof(TElement).GetHashCode();
if (obj == null) return result;
result += obj.Count;
result += obj.Select(element => _elementComparer.GetHashCode(element));
return result;
}
}
Usage:
void DoWork(Type type)
{
var props = type.GetProperties().Where(p => p.HasAttribute(MyAttribute)).ToList();
var tupleFactory = TupleFactory.Create(props.Select(p => new KeyValuePair<string, Type>(p.Name, p.PropertyType)));
var param = Expression.Parameter(type, "x");
var newEx = tupleFactory.MakeNewExpression(props.Select(p => Expression.Property(param, p)));
var lambda = Expression.Lambda(newEx, param); // <-- type is LambdaExpression, not dynamic
MyFunction(lambda);
}
i write some method for create class and property in run time with Reflection.Emit
my code is:
public class DynamicLibraryProperties
{
public string PropName { get; set; }
public Type PropType { get; set; }
public string DefaultValue { get; set; }
}
public class GenerateDynamicClass
{
public static void GenerateLegacyStructureObject(string libraryName, string className, List<DynamicLibraryProperties> properties)
{
ILGenerator ilgen = default(ILGenerator);
string library = string.Concat(libraryName, ".dll");
AssemblyBuilder asmBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(new AssemblyName(libraryName), AssemblyBuilderAccess.RunAndSave);
ModuleBuilder modBuilder = asmBuilder.DefineDynamicModule(libraryName, library);
TypeBuilder legacyBuilder = modBuilder.DefineType(string.Concat(libraryName, ".", className), TypeAttributes.Class | TypeAttributes.Public);
//Field Builder - Based on number of months add so many fields
foreach (DynamicLibraryProperties p in properties)
{
FieldBuilder field = legacyBuilder.DefineField(string.Concat("_", p.PropName), p.PropType, FieldAttributes.Private);
PropertyBuilder nameProp = legacyBuilder.DefineProperty(p.PropName, PropertyAttributes.HasDefault, p.PropType, null);
Type[] types = new Type[] { p.PropType };
dynamic typeConvertor = TypeDescriptor.GetConverter(p.PropType);
dynamic defaultValue = typeConvertor.ConvertFromString(p.DefaultValue);
ConstructorInfo ctor = typeof(DefaultValueAttribute).GetConstructor(types);
CustomAttributeBuilder customAttrib = new CustomAttributeBuilder(ctor, new object[] { defaultValue });
nameProp.SetCustomAttribute(customAttrib);
MethodAttributes getAttr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.SpecialName;
MethodBuilder getNameBuilder = legacyBuilder.DefineMethod(string.Concat("get_", p.PropName), getAttr, p.PropType, Type.EmptyTypes);
ilgen = getNameBuilder.GetILGenerator(); ilgen.Emit(OpCodes.Ldarg_0);
ilgen.Emit(OpCodes.Ldfld, field);
ilgen.Emit(OpCodes.Ret);
MethodBuilder setNameBuilder = legacyBuilder.DefineMethod(string.Concat("set_", p.PropName), getAttr, null, new Type[] { p.PropType });
ilgen = setNameBuilder.GetILGenerator();
ilgen.Emit(OpCodes.Ldarg_0);
ilgen.Emit(OpCodes.Ldarg_1);
ilgen.Emit(OpCodes.Stfld, field); ilgen.Emit(OpCodes.Ret);
nameProp.SetGetMethod(getNameBuilder);
nameProp.SetSetMethod(setNameBuilder);
}
Type objType = Type.GetType("System.Object");
ConstructorInfo objCtor = objType.GetConstructor(Type.EmptyTypes);
ilgen.Emit(OpCodes.Ldarg_0);
ilgen.Emit(OpCodes.Call, objCtor);
ilgen.Emit(OpCodes.Ret);
legacyBuilder.CreateType();
asmBuilder.Save(library);
}
}
and use this code like this
List<DynamicLibraryProperties> props = new List<DynamicLibraryProperties>();
props.Add(new DynamicLibraryProperties
{
PropName = "201203", PropType = typeof(float),DefaultValue = "0"
});
props.Add(new DynamicLibraryProperties { PropName = "201204", PropType = typeof(float) ,DefaultValue = "0"});
GenerateDynamicClass.GenerateLegacyStructureObject("test", "test", props);
Now i want create instance of Test class and set value for property value but i don't no how to do it, please help me , thanks all.
You can use Activator.CreateInstance for this, for that you need Type of your test class.
Change the method as below.
public static Type GenerateLegacyStructureObject(string libraryName, string className, List<DynamicLibraryProperties> properties)
{
//your code
Type t = legacyBuilder.CreateType();
asmBuilder.Save(library);
return t;
}
Then use it like this
Type testType = GenerateDynamicClass.GenerateLegacyStructureObject("test", "test", props);
object test = Activator.CreateInstance(testType);
Hope this helps