これは、直接電話をかけるのとほぼ同じ速さで、何でもできます。
using System.Collections.Generic;
using System.Linq.Expressions;
using System.Reflection;
public class FastMethodInfo
{
private delegate object ReturnValueDelegate(object instance, object[] arguments);
private delegate void VoidDelegate(object instance, object[] arguments);
public FastMethodInfo(MethodInfo methodInfo)
{
var instanceExpression = Expression.Parameter(typeof(object), "instance");
var argumentsExpression = Expression.Parameter(typeof(object[]), "arguments");
var argumentExpressions = new List<Expression>();
var parameterInfos = methodInfo.GetParameters();
for (var i = 0; i < parameterInfos.Length; ++i)
{
var parameterInfo = parameterInfos[i];
argumentExpressions.Add(Expression.Convert(Expression.ArrayIndex(argumentsExpression, Expression.Constant(i)), parameterInfo.ParameterType));
}
var callExpression = Expression.Call(!methodInfo.IsStatic ? Expression.Convert(instanceExpression, methodInfo.ReflectedType) : null, methodInfo, argumentExpressions);
if (callExpression.Type == typeof(void))
{
var voidDelegate = Expression.Lambda<VoidDelegate>(callExpression, instanceExpression, argumentsExpression).Compile();
Delegate = (instance, arguments) => { voidDelegate(instance, arguments); return null; };
}
else
Delegate = Expression.Lambda<ReturnValueDelegate>(Expression.Convert(callExpression, typeof(object)), instanceExpression, argumentsExpression).Compile();
}
private ReturnValueDelegate Delegate { get; }
public object Invoke(object instance, params object[] arguments)
{
return Delegate(instance, arguments);
}
}