public static Expression GetParamsMatch(Type type, Expression instance,
string membername, List <Expression> args)
{
// assume params
var methodInfos = type.GetMethods().Where(x => x.Name == membername);
var matchScore = new List <Tuple <MethodInfo, int> >();
foreach (var info in methodInfos.OrderByDescending(m => m.GetParameters().Count()))
{
var parameterInfos = info.GetParameters();
var lastParam = parameterInfos.Last();
var newArgs = args.Take(parameterInfos.Length - 1).ToList();
var paramArgs = args.Skip(parameterInfos.Length - 1).ToList();
int i = 0;
int k = 0;
foreach (var expression in newArgs)
{
k += TypeConversion.CanConvert(expression.Type, parameterInfos[i].ParameterType);
i++;
}
if (k > 0)
{
if (Attribute.IsDefined(lastParam, typeof(ParamArrayAttribute)))
{
k += paramArgs.Sum(arg => TypeConversion.CanConvert(arg.Type,
lastParam.ParameterType.GetElementType()));
}
}
matchScore.Add(new Tuple <MethodInfo, int>(info, k));
}
var info2 = matchScore.OrderBy(x => x.Item2).FirstOrDefault(x => x.Item2 >= 0);
if (info2 != null)
{
var parameterInfos2 = info2.Item1.GetParameters();
var lastParam2 = parameterInfos2.Last();
var newArgs2 = args.Take(parameterInfos2.Length - 1).ToList();
var paramArgs2 = args.Skip(parameterInfos2.Length - 1).ToList();
for (int i = 0; i < parameterInfos2.Length - 1; i++)
{
newArgs2[i] = TypeConversion.Convert(newArgs2[i], parameterInfos2[i].ParameterType);
}
var targetType = lastParam2.ParameterType.GetElementType();
newArgs2.Add(Expression.NewArrayInit(targetType,
paramArgs2.Select(x => TypeConversion.Convert(x, targetType))));
return(Expression.Call(instance, info2.Item1, newArgs2));
}
return(null);
}
