我正在尝试使用反射将未知对象添加到未知集合类型,并且在我实际执行添加"时遇到异常.我想知道是否有人可以指出我在做错什么还是其他选择?
I'm trying to use reflection to add an unknown object to an unknown collection type, and I'm getting an exception when I actually perform the "Add". I wonder if anyone can point out what I'm doing wrong or an alternative?
我的基本方法是遍历通过反射检索的IEnumerable,然后将新项目添加到辅助集合中,以后可以用作替换集合(包含一些更新值):
My basic approach is to iterate through an IEnumerable which was retrieved through reflection, and then adding new items to a secondary collection I can use later as the replacement collection (containing some updated values):
IEnumerable businessObjectCollection = businessObject as IEnumerable; Type customList = typeof(List<>) .MakeGenericType(businessObjectCollection.GetType()); var newCollection = (System.Collections.IList) Activator.CreateInstance(customList); foreach (EntityBase entity in businessObjectCollection) { // This is the area where the code is causing an exception newCollection.GetType().GetMethod("Add") .Invoke(newCollection, new object[] { entity }); }例外是:
"Eclipsys.Enterprise.Entities.Registration.VisitLite"类型的对象无法转换为"System.Collections.Generic.List`1 [Eclipsys.Enterprise.Entities.Registration.VisitLite]"类型.
Object of type 'Eclipsys.Enterprise.Entities.Registration.VisitLite' cannot be converted to type 'System.Collections.Generic.List`1[Eclipsys.Enterprise.Entities.Registration.VisitLite]'.
如果我将这行代码用于 Add(),则会得到另一个异常:
If I use this line of code for the Add() instead, I get a different exception:
newCollection.Add(entity);例外是:
值"的类型不是"System.Collections.Generic.List`1 [Eclipsys.Enterprise.Entities.Registration.VisitLite]",不能在此通用集合中使用.
The value "" is not of type "System.Collections.Generic.List`1[Eclipsys.Enterprise.Entities.Registration.VisitLite]" and cannot be used in this generic collection.
推荐答案根据第一个异常,您试图将 Eclipsys.Enterprise.Entities.Registration.VisitLite 强制转换为 List<>; .我认为那是你的问题.
According to a first exception you are trying to cast Eclipsys.Enterprise.Entities.Registration.VisitLite to List<>. I think that's your problem.
尝试一下:
businessObject = //your collection; //there might be two Add methods. Make sure you get the one which has one parameter. MethodInfo addMethod = businessObject.GetType().GetMethods() .Where(m => m.Name == "Add" && m.GetParameters().Count() == 1).FirstOrDefault(); foreach(object obj in businessObject as IEnumerable) { addMethod.Invoke(businessObject, new object[] { obj }); }更多推荐
如何使用反射将新项目添加到集合中
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