在运行时以编程方式获取摘要注释

Question

我正在寻找一种方法来以编程方式获取 ASP.net 中方法的 Xml-comments 的摘要部分。

我查看了之前的相关帖子，但它们没有提供在 Web 环境中执行此操作的方法。

我无法使用任何 3rd 方应用程序，并且由于网络环境，Visual Studio 插件也没有多大用处。

我发现的最接近工作解决方案的是 JimBlackler 项目，但它只适用于 DLL。

自然，诸如“提供 .CS 文件，获取 XML 文档”之类的内容将是最佳选择。

---

现在的情况

我有一个网络服务并试图为其动态生成文档。

阅读方法和属性很容易，但是获取每个方法的摘要让我有点失望。

/// <summary>
/// This Is what I'm trying to read
/// </summary>
public class SomeClass()
{
    /// <summary>
    /// This Is what I'm trying to read
    /// </summary>
    public void SomeMethod()
    {
    }
}

---

Answer 1

解决方法- 将 Program.DLL/EXE 上的反射与 Program.XML 文件一起使用

如果您查看由 Visual Studio 生成的同级 .XML 文件，您将看到 /members/member 的层次结构相当平坦。 您所要做的就是通过 MethodInfo 对象从您的 DLL 中获取每个方法。 一旦你有了这个对象，你就转向 XML 并使用 XPATH 来获取包含此方法的 XML 文档的成员。

成员前面有一封信。 方法的 XML 文档以“M:”开头，类以“T:”等开头。

加载您的兄弟 XML

string docuPath = dllPath.Substring(0, dllPath.LastIndexOf(".")) + ".XML";

if (File.Exists(docuPath))
{
  _docuDoc = new XmlDocument();
  _docuDoc.Load(docuPath);
}

使用此 xpath 获取表示方法 XML 文档的成员

string path = "M:" + mi.DeclaringType.FullName + "." + mi.Name;

XmlNode xmlDocuOfMethod = _docuDoc.SelectSingleNode(
    "//member[starts-with(@name, '" + path + "')]");

现在扫描“///”的所有行的子节点有时///摘要包含额外的空白，如果这很麻烦，请使用它来删除

var cleanStr = Regex.Replace(row.InnerXml, @"\s+", " ");

Answer 2

XML 摘要不存储在 .NET 程序集中 - 作为构建的一部分（假设您使用的是 Visual Studio），它可以选择写入 XML 文件。

因此，无法通过对已编译的 .NET 程序集（.EXE 或 .DLL）的反射来“提取”每个方法的 XML 摘要——因为数据根本不存在供您提取。 如果需要数据，则必须指示构建环境将 XML 文件作为构建过程的一部分输出，并在运行时解析这些 XML 文件以获取摘要信息。

Answer 3

您可以使用System.ComponentModel.DataAnnotations.DisplayAttribute属性“记录”您的方法，例如

[Display(Name = "Foo", Description = "Blah")]
void Foo()
{
}

然后使用反射在运行时提取描述。

Answer 4

由@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 ，这是我的解决方案的基础。

下面是对 Jim Blackler 代码的修改，使扩展方法脱离 MemberInfo 和 Type 对象，并添加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);
        }
    }
}

Answer 5

您可以使用Namotion.Reflection NuGet 包来获取这些信息：

string summary = typeof(Foo).GetXmlDocsSummary();

Answer 6

您可以查看https://github.com/NSwag/NSwag - nuget NSwag.CodeGeneration 的来源 - 它也有摘要，用法

var generator = new WebApiAssemblyToSwaggerGenerator(settings);<br/>
var swaggerService = generator.GenerateForController("namespace.someController");<br/>
// string with comments <br/>
var swaggerJson = swaggerService.ToJson(); 

（针对您的 dll 尝试 ILSPY 反编译器，您检查代码和注释）

Answer 7

如果您有权访问要获取评论的源代码，则可以使用Roslyn 编译器平台来执行此操作。 它基本上让您可以访问所有中间编译器元数据，并且您可以使用它做任何您想做的事情。

这比其他人建议的要复杂一些，但根据您的需求，可能是一种选择。

看起来这篇文章有一个类似的代码示例。