@OleksandrIeremenko 在此线程上发布的已删除帖子链接到本文https://jimblackler.net/blog/?p=49，这是我解决方案的基础。
以下是对 Jim Blackler 的代码的修改，该代码对 MemberInfo 和 Type 对象进行了扩展方法，并添加了返回摘要文本或空字符串（如果不可用）的代码。
用法
var typeSummary = typeof([Type Name]).GetSummary();
var methodSummary = typeof([Type Name]).GetMethod("[Method Name]").GetSummary();
扩展类
/// <summary>
/// Utility class to provide documentation for various types where available with the assembly
/// </summary>
public static class DocumentationExtensions
{
/// <summary>
/// Provides the documentation comments for a specific method
/// </summary>
/// <param name="methodInfo">The MethodInfo (reflection data ) of the member to find documentation for</param>
/// <returns>The XML fragment describing the method</returns>
public static XmlElement GetDocumentation(this MethodInfo methodInfo)
{
// Calculate the parameter string as this is in the member name in the XML
var parametersString = "";
foreach (var parameterInfo in methodInfo.GetParameters())
{
if (parametersString.Length > 0)
{
parametersString += ",";
}
parametersString += parameterInfo.ParameterType.FullName;
}
//AL: 15.04.2008 ==> BUG-FIX remove “()” if parametersString is empty
if (parametersString.Length > 0)
return XmlFromName(methodInfo.DeclaringType, 'M', methodInfo.Name + "(" + parametersString + ")");
else
return XmlFromName(methodInfo.DeclaringType, 'M', methodInfo.Name);
}
/// <summary>
/// Provides the documentation comments for a specific member
/// </summary>
/// <param name="memberInfo">The MemberInfo (reflection data) or the member to find documentation for</param>
/// <returns>The XML fragment describing the member</returns>
public static XmlElement GetDocumentation(this MemberInfo memberInfo)
{
// First character [0] of member type is prefix character in the name in the XML
return XmlFromName(memberInfo.DeclaringType, memberInfo.MemberType.ToString()[0], memberInfo.Name);
}
/// <summary>
/// Returns the Xml documenation summary comment for this member
/// </summary>
/// <param name="memberInfo"></param>
/// <returns></returns>
public static string GetSummary(this MemberInfo memberInfo)
{
var element = memberInfo.GetDocumentation();
var summaryElm = element?.SelectSingleNode("summary");
if (summaryElm == null) return "";
return summaryElm.InnerText.Trim();
}
/// <summary>
/// Provides the documentation comments for a specific type
/// </summary>
/// <param name="type">Type to find the documentation for</param>
/// <returns>The XML fragment that describes the type</returns>
public static XmlElement GetDocumentation(this Type type)
{
// Prefix in type names is T
return XmlFromName(type, 'T', "");
}
/// <summary>
/// Gets the summary portion of a type's documenation or returns an empty string if not available
/// </summary>
/// <param name="type"></param>
/// <returns></returns>
public static string GetSummary(this Type type)
{
var element = type.GetDocumentation();
var summaryElm = element?.SelectSingleNode("summary");
if (summaryElm == null) return "";
return summaryElm.InnerText.Trim();
}
/// <summary>
/// Obtains the XML Element that describes a reflection element by searching the
/// members for a member that has a name that describes the element.
/// </summary>
/// <param name="type">The type or parent type, used to fetch the assembly</param>
/// <param name="prefix">The prefix as seen in the name attribute in the documentation XML</param>
/// <param name="name">Where relevant, the full name qualifier for the element</param>
/// <returns>The member that has a name that describes the specified reflection element</returns>
private static XmlElement XmlFromName(this Type type, char prefix, string name)
{
string fullName;
if (string.IsNullOrEmpty(name))
fullName = prefix + ":" + type.FullName;
else
fullName = prefix + ":" + type.FullName + "." + name;
var xmlDocument = XmlFromAssembly(type.Assembly);
var matchedElement = xmlDocument["doc"]["members"].SelectSingleNode("member[@name='" + fullName + "']") as XmlElement;
return matchedElement;
}
/// <summary>
/// A cache used to remember Xml documentation for assemblies
/// </summary>
private static readonly Dictionary<Assembly, XmlDocument> Cache = new Dictionary<Assembly, XmlDocument>();
/// <summary>
/// A cache used to store failure exceptions for assembly lookups
/// </summary>
private static readonly Dictionary<Assembly, Exception> FailCache = new Dictionary<Assembly, Exception>();
/// <summary>
/// Obtains the documentation file for the specified assembly
/// </summary>
/// <param name="assembly">The assembly to find the XML document for</param>
/// <returns>The XML document</returns>
/// <remarks>This version uses a cache to preserve the assemblies, so that
/// the XML file is not loaded and parsed on every single lookup</remarks>
public static XmlDocument XmlFromAssembly(this Assembly assembly)
{
if (FailCache.ContainsKey(assembly))
{
throw FailCache[assembly];
}
try
{
if (!Cache.ContainsKey(assembly))
{
// load the docuemnt into the cache
Cache[assembly] = XmlFromAssemblyNonCached(assembly);
}
return Cache[assembly];
}
catch (Exception exception)
{
FailCache[assembly] = exception;
throw;
}
}
/// <summary>
/// Loads and parses the documentation file for the specified assembly
/// </summary>
/// <param name="assembly">The assembly to find the XML document for</param>
/// <returns>The XML document</returns>
private static XmlDocument XmlFromAssemblyNonCached(Assembly assembly)
{
var assemblyFilename = assembly.Location;
if (!string.IsNullOrEmpty(assemblyFilename))
{
StreamReader streamReader;
try
{
streamReader = new StreamReader(Path.ChangeExtension(assemblyFilename, ".xml"));
}
catch (FileNotFoundException exception)
{
throw new Exception("XML documentation not present (make sure it is turned on in project properties when building)", exception);
}
var xmlDocument = new XmlDocument();
xmlDocument.Load(streamReader);
return xmlDocument;
}
else
{
throw new Exception("Could not ascertain assembly filename", null);
}
}
}