c# - 创建DirectoryEntry实例以用于测试

我试图创建DirectoryEntry的实例，以便可以使用它来测试将传递给DirectoryEntry的一些代码。但是，尽管进行了很多尝试，我仍然找不到一种实例化DE并将其初始化为PropertyCollection的方法。

我有以下代码是从another answer on SO提取并修改的，该代码除了SearchResult对象以外，都在执行相同的过程。似乎Add方法已被完全禁用，并且我找不到在PropertyCollection上调用构造函数以传递某些属性的方法。

using System.Collections;
using System.DirectoryServices;
using System.Globalization;
using System.Reflection;
using System.Runtime.Serialization;

public static class DirectoryEntryFactory
{
    const BindingFlags nonPublicInstance = BindingFlags.NonPublic | BindingFlags.Instance;
    const BindingFlags publicInstance = BindingFlags.Public | BindingFlags.Instance;

    public static DirectoryEntry Construct<T>(T anonInstance)
    {
        var e = GetUninitializedObject<DirectoryEntry>();

        SetPropertiesField(e);

        var dictionary = (IDictionary)e.Properties;
        var type = typeof(T);
        var propertyInfos = type.GetProperties(publicInstance);

        foreach (var propertyInfo in propertyInfos)
        {
            var value = propertyInfo.GetValue(anonInstance, null);
            var valueCollection = GetUninitializedObject<PropertyValueCollection>();
            var innerList = GetInnerList(valueCollection);
            innerList.Add(value);

            var lowerKey = propertyInfo.Name.ToLower(CultureInfo.InvariantCulture);

            // These both throw exceptions saying you can't add to a PropertyCollection
            //(typeof(PropertyCollection)).InvokeMember("System.Collections.IDictionary.Add", nonPublicInstance | BindingFlags.InvokeMethod, null, dictionary, new object[] { propertyInfo.Name, value });
            //dictionary.Add(lowerKey, propertyCollection);
        }

        return e;
    }

    private static ArrayList GetInnerList(object propertyCollection)
    {
        var propertyInfo = typeof(PropertyValueCollection).GetProperty("InnerList", nonPublicInstance);
        return (ArrayList)propertyInfo.GetValue(propertyCollection, null);
    }

    private static void SetPropertiesField(DirectoryEntry e)
    {
        var propertiesField = typeof(DirectoryEntry).GetField("propertyCollection", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
        propertiesField.SetValue(e, GetUninitializedObject<PropertyCollection>());
    }

    private static T GetUninitializedObject<T>()
    {
        return (T)FormatterServices.GetUninitializedObject(typeof(T));
    }
}

用途旨在

DirectoryEntry e = DirectoryEntryFactory.Construct(new { attr1 = "Hello", attr2 = "World"});

我希望我已经错过了一些东西，因为我是在愤怒中使用反射的新手。

最佳答案

我不熟悉DirectoryEntry本身，但是我非常喜欢Adapter模式进行测试。您不得不做这样的事情很烦人，但是代码本身很琐碎，可以将这些类放在项目文件夹中以将其隐藏在远离主项目的地方。

例如，我有一个FileInfoAdapter和DirectoryInfoAdapter，它们包装了那些接触文件系统的类。

FileInfoAdapter:

public class FileInfoAdapter : IFileInfo
{
    private readonly FileSystemInfo _fi;

    public FileInfoAdapter(string fileName)
        : this(new FileInfo(fileName))
    { }

    public FileInfoAdapter(FileSystemInfo fi)
    {
        _fi = fi;
    }

    public string Name { get { return _fi.Name; } }
    public string FullName { get { return _fi.FullName; } }
    public bool Exists { get { return _fi.Exists; } }
}