反射IsGenericType

var propertyType = propertyInfo.PropertyType;
if (propertyType.IsGenericType &&
        propertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
    {
      propertyType = propertyType.GetGenericArguments()[0];
    }
model.ModelProperties.Add(new KeyValuePair<Type, string>
                        (propertyType.Name,propertyInfo.Name));