static partial class ReflectionUtility
{/// <summary>/// Indicates whether or not the specified type is a list./// </summary>/// <param name="type">The type to query</param>/// <returns>True if the type is a list, otherwise false</returns>public static bool IsList(Type type){if (null == type)throw new ArgumentNullException("type");if (typeof(System.Collections.IList).IsAssignableFrom(type))return true;foreach (var it in type.GetInterfaces())if (it.IsGenericType && typeof(IList<>) == it.GetGenericTypeDefinition())return true;return false;}/// <summary>/// Retrieves the collection element type from this type/// </summary>/// <param name="type">The type to query</param>/// <returns>The element type of the collection or null if the type was not a collection/// </returns>public static Type GetCollectionElementType(Type type){if (null == type)throw new ArgumentNullException("type");// first try the generic way// this is easy, just query the IEnumerable<T> interface for its generic parametervar etype = typeof(IEnumerable<>);foreach (var bt in type.GetInterfaces())if (bt.IsGenericType && bt.GetGenericTypeDefinition() == etype)return bt.GetGenericArguments()[0];// now try the non-generic way// if it's a dictionary we always return DictionaryEntryif (typeof(System.Collections.IDictionary).IsAssignableFrom(type))return typeof(System.Collections.DictionaryEntry);// if it's a list we look for an Item property with an int index parameter// where the property type is anything but objectif (typeof(System.Collections.IList).IsAssignableFrom(type)){foreach (var prop in type.GetProperties()){if ("Item" == prop.Name && typeof(object)!=prop.PropertyType){var ipa = prop.GetIndexParameters();if (1 == ipa.Length && typeof(int) == ipa[0].ParameterType){return prop.PropertyType;}}}}// if it's a collection, we look for an Add() method whose parameter is // anything but objectif(typeof(System.Collections.ICollection).IsAssignableFrom(type)){foreach(var meth in type.GetMethods()){if("Add"==meth.Name){var pa = meth.GetParameters();if (1 == pa.Length && typeof(object) != pa[0].ParameterType)return pa[0].ParameterType;}}}if (typeof(System.Collections.IEnumerable).IsAssignableFrom(type))return typeof(object);return null;}
}

首先，我们有一个上面没有提到的IsList()方法。这是一种实用程序方法，当我对集合进行反射时，我发现自己需要很多，因此在此提供了它。它所做的只是确定传入的类型是否为列表。

Console.WriteLine(ReflectionUtility.GetCollectionElementType(typeof(List<string>)));
Console.WriteLine(ReflectionUtility.GetCollectionElementType(typeof(List<int>)));
Console.WriteLine(ReflectionUtility.GetCollectionElementType(typeof(CodeNamespaceCollection)));
Console.WriteLine(ReflectionUtility.GetCollectionElementType(typeof(CodeStatementCollection)));

这应该足以使您继续使用此代码。请享用！