Question

考虑以下计划

 public static void Fill<T1, T2>(ObjectResult<T1> Source, List<T2> Destination)
            where T2 : new()
        {
            Destination.AddRange(Source.Select(CreateMapping<T1, T2>()));
        }

        public static Func<T1, T2> CreateMapping<T1, T2>()
        where T2 : new()
        {
            var typeOfSource = typeof(T1);
            var typeOfDestination = typeof(T2);

            // use reflection to get a list of the properties on the source and destination types
            var sourceProperties = typeOfSource.GetProperties();
            var destinationProperties = typeOfDestination.GetProperties();

            // join the source properties with the destination properties based on name
            var properties = from sourceProperty in sourceProperties
                             join destinationProperty in destinationProperties
                             on sourceProperty.Name equals destinationProperty.Name
                             select new { SourceProperty = sourceProperty, DestinationProperty = destinationProperty };

            return (x) =>
            {
                var y = new T2();

                foreach (var property in properties)
                {
                    var value = property.SourceProperty.GetValue(x, null);
                    property.DestinationProperty.SetValue(y, value, null);
                }

                return y;
            };
        }

我们接受ObjectResult集合（实体框架的数据类型）并返回通用列表。它工作正常，但在某些情况下它抛出异常，因为＆＃34;对象无法枚举两次＆＃34; ...

有没有更好的方法来重写函数？

Answer 1

如果您对ObjectResult的多次枚举有问题，请不要将它传递给您的方法并控制枚举：

public static void Fill<T1, T2>(List<T1> Source, List<T2> Destination)

并用

调用它

Fill(objectResult.ToList(), destinationList);

顺便说一下。为什么不使用AutoMapper呢？

将通用ObjectResult集合（实体框架数据类型）转换为通用列表集合的更好方法是什么？

1 个答案: