Question

我正在尝试创建DirectoryEntry的实例，以便我可以使用它来测试一些将传递DirectoryEntry的代码。然而，尽管尝试了很多，但我找不到实例化DE并初始化它的PropertyCollection的方法。

我有以下代码，它是从another answer on SO获取和修改的，它正在执行相同的过程但是对于SearchResult对象。似乎Add方法已被完全禁用，我无法找到一种方法来调用PropertyCollection上的构造函数来传递一些属性。

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));
    }
}

用法旨在

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

我希望自己错过了一些东西，因为我很擅长在愤怒中使用反射。

Answer 1

我不熟悉DirectoryEntry本身，但我非常喜欢用于测试的Adapter模式。你不得不做一件令人烦恼的事情，但代码本身很简单，类可以放在一个项目文件夹中，以隐藏它们远离你的主项目。

例如，我有一个FileInfoAdapter和DirectoryInfoAdapter来包装那些触及文件系统的类。

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; } }
}

创建DirectoryEntry实例以用于测试

1 个答案: