C#对象数组 [英] C# object to array

问题描述

使用反射，我有一个对象，我需要将该对象转换为可迭代的项目列表(类型未知，将是对象).使用监视"窗口，我可以看到我的对象是某种类型的数组，因为它告诉我元素的数量，并且可以分解树视图以查看元素本身.

Using reflection I have an object which I need to cast into an iterable list of items (type unknown, will be object). Using the Watch window I can see my object is an array of some type as it tells me the number of elements and I can explode the tree view to see the elements themselves.

首先，我需要检查传递的对象是否为某种数组(可能是List，可能是object []，等等).然后，我需要遍历该数组.但是，我无法进行类型转换.

Firstly, I need to check that the object passed is some kind of array (might be List, might be object[], etc). Then I need to iterate through that array. However, I can't do the type conversion.

这是我的使用方式(缩写):

Here's how I'm using it (abbreviated):

    private static void Example(object instance, PropertyInfo propInfo)
    {
        object anArray = propInfo.GetValue(instance, null);
        ArrayList myList = anArray as ArrayList;
        foreach (object element in myList)
        {
            // etc
        }
    }

我尝试了各种不同的演员.上面没有引发异常，但是当anArray实际上存在并且包含项目时，mylist为null.被保存的实际实例是强类型的List，但是如果需要的话可以采用形式的有限子集.但是练习的要点是，这个Example()方法不知道该属性的基本类型.

I've tried various different casts. The above doesn't raise an exception but mylist is null when anArray actually exists and contains items. The actual instance being saved is a strongly-typed List<> but could take a limited subset of forms if necessary. But the point of the exercise is that this Example() method doesn't know the basic type of the property.

推荐答案

仅当对象实际上是 是ArrayList时，才能将其投射到ArrayList.例如，它不能与System.Array或System.Collections.Generic.List`1一起使用.

Casting it to an ArrayList is only going to work if the object actually is an ArrayList. It wont work with a System.Array, or a System.Collections.Generic.List`1 for example.

我认为您实际上应该将其转换为IEnumerable，因为这是您循环访问它的唯一要求...

I think what you actually should do is cast it to IEnumerable, since that is your only requirement to loop over it...

object anArray = propInfo.GetValue(instance, null);
IEnumerable enumerable = anArray as IEnumerable;
if (enumerable != null)
{
    foreach(object element in enumerable)
    {
        // etc...
    }
}

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