关于ASP.NET Web Api的HelpPage文档注释问题

以前我用微软的HelpPage来自动生成的webAPI帮助文档。在使用了一段时间后发现只能显示Controller上面写的注释文档内容。以前总以为是微软这个类库的bug。后来才明白了是由于我的设置不当。

微软的HelpPage类库controller上的注释AlarmRecodrdDto文档

我们可以很清楚的看到，返回的`AlarmRecodrdDto`并没有注释文档啊！可是我已经在类库的中写过了该代码的注释的。为毛就没有呢？？？其实啊，我们的注释文档是自动生成xml文件，再由HelpPage来读取该xml中的注释信息，最后展示在页面上。那些没有注释的文档是由于我们的代码注释没有生成对应的注释xml文件，所以就没法读取啦！！！

明白问题出在哪里了就可以动手解决问题了！！！

1. 设置指定类库中要生成的注释xml路径

GTCASP.Services.xmlGTCASP.Models.xmlXMLDocument.xml

2. 添加一个可以读取xml文件信息的类

using System;
using System.Linq;
using System.Reflection;
using System.Web.Http.Controllers;
using System.Web.Http.Description;
using GTCASP.Website.Areas.HelpPage.ModelDescriptions;namespace GTCASP.Website.Areas.HelpPage.Models
{
    /// <summary>A custom
    /// <see cref="IDocumentationProvider"/>
    /// that reads the API documentation from a collection of XML documentation files.
    /// </summary>
    public class MultiXmlDocumentationProvider : IDocumentationProvider, IModelDocumentationProvider
    {
        /*********
    ** Properties
    *********/
        /// <summary>The internal documentation providers for specific files.</summary>
        private readonly XmlDocumentationProvider[] Providers;        /*********
        ** Public methods
        *********/
        /// <summary>Construct an instance.</summary>
        /// <param name="paths">The physical paths to the XML documents.</param>
        public MultiXmlDocumentationProvider(params string[] paths)
        {
            this.Providers = paths.Select(p => new XmlDocumentationProvider(p)).ToArray();
        }        /// <summary>Gets the documentation for a subject.</summary>
        /// <param name="subject">The subject to document.</param>
        public string GetDocumentation(MemberInfo subject)
        {
            return this.GetFirstMatch(p => p.GetDocumentation(subject));
        }        /// <summary>Gets the documentation for a subject.</summary>
        /// <param name="subject">The subject to document.</param>
        public string GetDocumentation(Type subject)
        {
            return this.GetFirstMatch(p => p.GetDocumentation(subject));
        }        /// <summary>Gets the documentation for a subject.</summary>
        /// <param name="subject">The subject to document.</param>
        public string GetDocumentation(HttpControllerDescriptor subject)
        {
            return this.GetFirstMatch(p => p.GetDocumentation(subject));
        }        /// <summary>Gets the documentation for a subject.</summary>
        /// <param name="subject">The subject to document.</param>
        public string GetDocumentation(HttpActionDescriptor subject)
        {
            return this.GetFirstMatch(p => p.GetDocumentation(subject));
        }        /// <summary>Gets the documentation for a subject.</summary>
        /// <param name="subject">The subject to document.</param>
        public string GetDocumentation(HttpParameterDescriptor subject)
        {
            return this.GetFirstMatch(p => p.GetDocumentation(subject));
        }        /// <summary>Gets the documentation for a subject.</summary>
        /// <param name="subject">The subject to document.</param>
        public string GetResponseDocumentation(HttpActionDescriptor subject)
        {
            return this.GetFirstMatch(p => p.GetDocumentation(subject));
        }        /*********
        ** Private methods
        *********/
        /// <summary>Get the first valid result from the collection of XML documentation providers.</summary>
        /// <param name="expr">The method to invoke.</param>
        private string GetFirstMatch(Func<XmlDocumentationProvider, string> expr)
        {
            return this.Providers
                .Select(expr)
                .FirstOrDefault(p => !String.IsNullOrWhiteSpace(p));
        }
    }
}