FastInvoke.cs

using System;
using System.Linq.Expressions;
using System.Reflection;


namespace DataDrain.Mapping
{
public class FastInvoke
    {
        public static Func<T, TReturn> BuildTypedGetter<T, TReturn>(PropertyInfo propertyInfo)
        {
            var reflGet = (Func<T, TReturn>) Delegate.CreateDelegate(typeof(Func<T, TReturn>), propertyInfo.GetGetMethod());
            return reflGet;
        }
 
        public static Action<T, TProperty> BuildTypedSetter<T, TProperty>(PropertyInfo propertyInfo)
        {
            var reflSet = (Action<T, TProperty>)Delegate.CreateDelegate(typeof(Action<T, TProperty>), propertyInfo.GetSetMethod());
            return reflSet;
        }
 
        public static Action<T, object> BuildUntypedSetter<T>(PropertyInfo propertyInfo)
        {
            var targetType = propertyInfo.DeclaringType;
            var methodInfo = propertyInfo.GetSetMethod();
            var exTarget = Expression.Parameter(targetType, "t");
            var exValue = Expression.Parameter(typeof(object), "p");
            // wir betreiben ein anObject.SetPropertyValue(object)
            var exBody = Expression.Call(exTarget, methodInfo,Expression.Convert(exValue, propertyInfo.PropertyType));
            var lambda = Expression.Lambda<Action<T, object>>(exBody, exTarget, exValue);
            // (t, p) => t.set_StringValue(Convert(p))
 
            var action = lambda.Compile();
            return action;
        }
 
        public static Func<T, object> BuildUntypedGetter<T>(PropertyInfo propertyInfo)
        {
            var targetType = propertyInfo.DeclaringType;
            var methodInfo = propertyInfo.GetGetMethod();
 
            var exTarget = Expression.Parameter(targetType, "t");
            var exBody = Expression.Call(exTarget, methodInfo);
            var exBody2 = Expression.Convert(exBody, typeof(object));
 
            var lambda = Expression.Lambda<Func<T, object>>(exBody2, exTarget);
            // t => Convert(t.get_Foo())
 
            var action = lambda.Compile();
            return action;
        }
    }
}