Question

方法签名：

public static IDictionary<string, object> ListX(this object instance)

代码：

          if (instance == null)
                throw new NullReferenceException();

            var result = instance as IDictionary<string, object>;
            if (result != null)
                return result;
                return instance.GetType()
                    .GetProperties()
                    .ToDictionary(x => x.Name, x =>
                    {
  object value = x.GetValue(instance);
            if (value != null)
            {
                var valueType = value.GetType();

                // Whe should manually check for string type because IsPrimitive will return false in case of string
                if (valueType.IsPrimitive || valueType == typeof(string))
                {

                    return value;
                }
                // If the value type is enumerable then we iterate over and recursively call ToDictionary on each item
                else if (valueType.GetInterfaces().Any(t => t == typeof(IEnumerable)))
                {
                    List<object> elements = new List<object>();
                    foreach (var item in value as IEnumerable)
                    {
                        elements.Add(item.ToDictionary());
                    }
                    return elements;
                }
                // The value type is a complex type so we recursively call ToDictionary
                else
                {
                    return value.ToDictionary();
                }
            }
            return null;
                    });

对于x，我得到Cannot convert lambda expression to type 'System.Collections.Generic.IEqualityComparer<string>' because it is not a delegate type。

这里的问题是什么？

好的，我更新了该代码。

Answer 1

问题是ToDictionary期望IEqualityComparer作为第二个参数，而你提供的不会实现该接口。

您在以下链接中获得了有关如何使用此metod的说明：http://www.dotnetperls.com/todictionary

无法将lambda表达式转换为类型'System.Collections.Generic.IEqualityComparer <string>'，因为它不是委托类型

1 个答案: