WebApi 插件式构建方案：重写的控制器获取工厂

时间：2023-03-09 06:05:44
WebApi 插件式构建方案：重写的控制器获取工厂

body {
border: 1px solid #ddd;
outline: 1300px solid #fff;
margin: 16px auto;
}

body .markdown-body
{
padding: 30px;
}

@font-face {
font-family: octicons-anchor;
src: url(data:font/woff;charset=utf-8;base64,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) format('woff');
}

.markdown-body {
-ms-text-size-adjust: 100%;
-webkit-text-size-adjust: 100%;
color: #333;
overflow: hidden;
font-family: "Helvetica Neue", Helvetica, "Segoe UI", Arial, freesans, sans-serif;
font-size: 16px;
line-height: 1.6;
word-wrap: break-word;
}

.markdown-body a {
background: transparent;
}

.markdown-body a:active,
.markdown-body a:hover {
outline: 0;
}

.markdown-body strong {
font-weight: bold;
}

.markdown-body h1 {
font-size: 2em;
margin: 0.67em 0;
}

.markdown-body img {
border: 0;
}

.markdown-body hr {
-moz-box-sizing: content-box;
box-sizing: content-box;
height: 0;
}

.markdown-body pre {
overflow: auto;
}

.markdown-body code,
.markdown-body kbd,
.markdown-body pre {
font-family: monospace, monospace;
font-size: 1em;
}

.markdown-body input {
color: inherit;
font: inherit;
margin: 0;
}

.markdown-body html input[disabled] {
cursor: default;
}

.markdown-body input {
line-height: normal;
}

.markdown-body input[type="checkbox"] {
-moz-box-sizing: border-box;
box-sizing: border-box;
padding: 0;
}

.markdown-body table {
border-collapse: collapse;
border-spacing: 0;
}

.markdown-body td,
.markdown-body th {
padding: 0;
}

.markdown-body * {
-moz-box-sizing: border-box;
box-sizing: border-box;
}

.markdown-body input {
font: 13px/1.4 Helvetica, arial, freesans, clean, sans-serif, "Segoe UI Emoji", "Segoe UI Symbol";
}

.markdown-body a {
color: #4183c4;
text-decoration: none;
}

.markdown-body a:hover,
.markdown-body a:focus,
.markdown-body a:active {
text-decoration: underline;
}

.markdown-body hr {
height: 0;
margin: 15px 0;
overflow: hidden;
background: transparent;
border: 0;
border-bottom: 1px solid #ddd;
}

.markdown-body hr:before {
display: table;
content: "";
}

.markdown-body hr:after {
display: table;
clear: both;
content: "";
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
margin-top: 15px;
margin-bottom: 15px;
line-height: 1.1;
}

.markdown-body h1 {
font-size: 30px;
}

.markdown-body h2 {
font-size: 21px;
}

.markdown-body h3 {
font-size: 16px;
}

.markdown-body h4 {
font-size: 14px;
}

.markdown-body h5 {
font-size: 12px;
}

.markdown-body h6 {
font-size: 11px;
}

.markdown-body blockquote {
margin: 0;
}

.markdown-body ul,
.markdown-body ol {
padding: 0;
margin-top: 0;
margin-bottom: 0;
}

.markdown-body ol ol,
.markdown-body ul ol {
list-style-type: lower-roman;
}

.markdown-body ul ul ol,
.markdown-body ul ol ol,
.markdown-body ol ul ol,
.markdown-body ol ol ol {
list-style-type: lower-alpha;
}

.markdown-body dd {
margin-left: 0;
}

.markdown-body code {
font: 12px Consolas, "Liberation Mono", Menlo, Courier, monospace;
}

.markdown-body pre {
margin-top: 0;
margin-bottom: 0;
font: 12px Consolas, "Liberation Mono", Menlo, Courier, monospace;
}

.markdown-body .octicon {
font: normal normal 16px octicons-anchor;
line-height: 1;
display: inline-block;
text-decoration: none;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
-webkit-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
}

.markdown-body .octicon-link:before {
content: '\f05c';
}

.markdown-body>*:first-child {
margin-top: 0 !important;
}

.markdown-body>*:last-child {
margin-bottom: 0 !important;
}

.markdown-body .anchor {
position: absolute;
top: 0;
bottom: 0;
left: 0;
display: block;
padding-right: 6px;
padding-left: 30px;
margin-left: -30px;
}

.markdown-body .anchor:focus {
outline: none;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
position: relative;
margin-top: 1em;
margin-bottom: 16px;
font-weight: bold;
line-height: 1.4;
}

.markdown-body h1 .octicon-link,
.markdown-body h2 .octicon-link,
.markdown-body h3 .octicon-link,
.markdown-body h4 .octicon-link,
.markdown-body h5 .octicon-link,
.markdown-body h6 .octicon-link {
display: none;
color: #000;
vertical-align: middle;
}

.markdown-body h1:hover .anchor,
.markdown-body h2:hover .anchor,
.markdown-body h3:hover .anchor,
.markdown-body h4:hover .anchor,
.markdown-body h5:hover .anchor,
.markdown-body h6:hover .anchor {
padding-left: 8px;
margin-left: -30px;
line-height: 1;
text-decoration: none;
}

.markdown-body h1:hover .anchor .octicon-link,
.markdown-body h2:hover .anchor .octicon-link,
.markdown-body h3:hover .anchor .octicon-link,
.markdown-body h4:hover .anchor .octicon-link,
.markdown-body h5:hover .anchor .octicon-link,
.markdown-body h6:hover .anchor .octicon-link {
display: inline-block;
}

.markdown-body h1 {
padding-bottom: 0.3em;
font-size: 2.25em;
line-height: 1.2;
border-bottom: 1px solid #eee;
}

.markdown-body h2 {
padding-bottom: 0.3em;
font-size: 1.75em;
line-height: 1.225;
border-bottom: 1px solid #eee;
}

.markdown-body h3 {
font-size: 1.5em;
line-height: 1.43;
}

.markdown-body h4 {
font-size: 1.25em;
}

.markdown-body h5 {
font-size: 1em;
}

.markdown-body h6 {
font-size: 1em;
color: #777;
}

.markdown-body p,
.markdown-body blockquote,
.markdown-body ul,
.markdown-body ol,
.markdown-body dl,
.markdown-body table,
.markdown-body pre {
margin-top: 0;
margin-bottom: 16px;
}

.markdown-body hr {
height: 4px;
padding: 0;
margin: 16px 0;
background-color: #e7e7e7;
border: 0 none;
}

.markdown-body ul,
.markdown-body ol {
padding-left: 2em;
}

.markdown-body ul ul,
.markdown-body ul ol,
.markdown-body ol ol,
.markdown-body ol ul {
margin-top: 0;
margin-bottom: 0;
}

.markdown-body li>p {
margin-top: 16px;
}

.markdown-body dl {
padding: 0;
}

.markdown-body dl dt {
padding: 0;
margin-top: 16px;
font-size: 1em;
font-style: italic;
font-weight: bold;
}

.markdown-body dl dd {
padding: 0 16px;
margin-bottom: 16px;
}

.markdown-body blockquote {
padding: 0 15px;
color: #777;
border-left: 4px solid #ddd;
}

.markdown-body blockquote>:first-child {
margin-top: 0;
}

.markdown-body blockquote>:last-child {
margin-bottom: 0;
}

.markdown-body table {
display: block;
width: 100%;
overflow: auto;
word-break: normal;
word-break: keep-all;
}

.markdown-body table th {
font-weight: bold;
}

.markdown-body table th,
.markdown-body table td {
padding: 6px 13px;
border: 1px solid #ddd;
}

.markdown-body table tr {
background-color: #fff;
border-top: 1px solid #ccc;
}

.markdown-body table tr:nth-child(2n) {
background-color: #f8f8f8;
}

.markdown-body img {
max-width: 100%;
-moz-box-sizing: border-box;
box-sizing: border-box;
}

.markdown-body code {
padding: 0;
padding-top: 0.2em;
padding-bottom: 0.2em;
margin: 0;
font-size: 85%;
background-color: rgba(0,0,0,0.04);
border-radius: 3px;
}

.markdown-body code:before,
.markdown-body code:after {
letter-spacing: -0.2em;
content: "\00a0";
}

.markdown-body pre>code {
padding: 0;
margin: 0;
font-size: 100%;
word-break: normal;
white-space: pre;
background: transparent;
border: 0;
}

.markdown-body .highlight {
margin-bottom: 16px;
}

.markdown-body .highlight pre,
.markdown-body pre {
padding: 16px;
overflow: auto;
font-size: 85%;
line-height: 1.45;
background-color: #f7f7f7;
border-radius: 3px;
}

.markdown-body .highlight pre {
margin-bottom: 0;
word-break: normal;
}

.markdown-body pre {
word-wrap: normal;
}

.markdown-body pre code {
display: inline;
max-width: initial;
padding: 0;
margin: 0;
overflow: initial;
line-height: inherit;
word-wrap: normal;
background-color: transparent;
border: 0;
}

.markdown-body pre code:before,
.markdown-body pre code:after {
content: normal;
}

.markdown-body .highlight {
background: #fff;
}

.markdown-body .highlight .h {
color: #333;
font-style: normal;
font-weight: normal;
}

.markdown-body .highlight .mf,
.markdown-body .highlight .mh,
.markdown-body .highlight .mi,
.markdown-body .highlight .mo,
.markdown-body .highlight .il,
.markdown-body .highlight .m {
color: #945277;
}

.markdown-body .highlight .s,
.markdown-body .highlight .sb,
.markdown-body .highlight .sc,
.markdown-body .highlight .sd,
.markdown-body .highlight .s2,
.markdown-body .highlight .se,
.markdown-body .highlight .sh,
.markdown-body .highlight .si,
.markdown-body .highlight .sx,
.markdown-body .highlight .s1 {
color: #df5000;
}

.markdown-body .highlight .kc,
.markdown-body .highlight .kd,
.markdown-body .highlight .kn,
.markdown-body .highlight .kp,
.markdown-body .highlight .kr,
.markdown-body .highlight .kt,
.markdown-body .highlight .k,
.markdown-body .highlight .o {
font-weight: bold;
}

.markdown-body .highlight .kt {
color: #458;
}

.markdown-body .highlight .c,
.markdown-body .highlight .cm,
.markdown-body .highlight .c1 {
color: #998;
font-style: italic;
}

.markdown-body .highlight .cp,
.markdown-body .highlight .cs,
.markdown-body .highlight .cp .h {
color: #999;
font-weight: bold;
}

.markdown-body .highlight .cs {
font-style: italic;
}

.markdown-body .highlight .n {
color: #333;
}

.markdown-body .highlight .na,
.markdown-body .highlight .nv,
.markdown-body .highlight .vc,
.markdown-body .highlight .vg,
.markdown-body .highlight .vi {
color: #008080;
}

.markdown-body .highlight .nb {
color: #0086B3;
}

.markdown-body .highlight .nc {
color: #458;
font-weight: bold;
}

.markdown-body .highlight .no {
color: #094e99;
}

.markdown-body .highlight .ni {
color: #800080;
}

.markdown-body .highlight .ne {
color: #990000;
font-weight: bold;
}

.markdown-body .highlight .nf {
color: #945277;
font-weight: bold;
}

.markdown-body .highlight .nn {
color: #555;
}

.markdown-body .highlight .nt {
color: #000080;
}

.markdown-body .highlight .err {
color: #a61717;
background-color: #e3d2d2;
}

.markdown-body .highlight .gd {
color: #000;
background-color: #fdd;
}

.markdown-body .highlight .gd .x {
color: #000;
background-color: #faa;
}

.markdown-body .highlight .ge {
font-style: italic;
}

.markdown-body .highlight .gr {
color: #aa0000;
}

.markdown-body .highlight .gh {
color: #999;
}

.markdown-body .highlight .gi {
color: #000;
background-color: #dfd;
}

.markdown-body .highlight .gi .x {
color: #000;
background-color: #afa;
}

.markdown-body .highlight .go {
color: #888;
}

.markdown-body .highlight .gp {
color: #555;
}

.markdown-body .highlight .gs {
font-weight: bold;
}

.markdown-body .highlight .gu {
color: #800080;
font-weight: bold;
}

.markdown-body .highlight .gt {
color: #aa0000;
}

.markdown-body .highlight .ow {
font-weight: bold;
}

.markdown-body .highlight .w {
color: #bbb;
}

.markdown-body .highlight .sr {
color: #017936;
}

.markdown-body .highlight .ss {
color: #8b467f;
}

.markdown-body .highlight .bp {
color: #999;
}

.markdown-body .highlight .gc {
color: #999;
background-color: #EAF2F5;
}

.markdown-body kbd {
background-color: #e7e7e7;
background-image: -webkit-linear-gradient(#fefefe, #e7e7e7);
background-image: linear-gradient(#fefefe, #e7e7e7);
background-repeat: repeat-x;
display: inline-block;
padding: 3px 5px;
font: 11px Consolas, "Liberation Mono", Menlo, Courier, monospace;
line-height: 10px;
color: #000;
border: 1px solid #cfcfcf;
border-radius: 2px;
}

.markdown-body .highlight .pl-coc,
.markdown-body .highlight .pl-entm,
.markdown-body .highlight .pl-eoa,
.markdown-body .highlight .pl-mai .pl-sf,
.markdown-body .highlight .pl-pdv,
.markdown-body .highlight .pl-sc,
.markdown-body .highlight .pl-sr,
.markdown-body .highlight .pl-v,
.markdown-body .highlight .pl-vpf {
color: #0086b3;
}

.markdown-body .highlight .pl-eoac,
.markdown-body .highlight .pl-mdht,
.markdown-body .highlight .pl-mi1,
.markdown-body .highlight .pl-mri,
.markdown-body .highlight .pl-va,
.markdown-body .highlight .pl-vpu {
color: #008080;
}

.markdown-body .highlight .pl-c,
.markdown-body .highlight .pl-pdc {
color: #b4b7b4;
font-style: italic;
}

.markdown-body .highlight .pl-k,
.markdown-body .highlight .pl-ko,
.markdown-body .highlight .pl-kolp,
.markdown-body .highlight .pl-mc,
.markdown-body .highlight .pl-mr,
.markdown-body .highlight .pl-ms,
.markdown-body .highlight .pl-s,
.markdown-body .highlight .pl-sok,
.markdown-body .highlight .pl-st {
color: #6e5494;
}

.markdown-body .highlight .pl-ef,
.markdown-body .highlight .pl-enf,
.markdown-body .highlight .pl-enm,
.markdown-body .highlight .pl-entc,
.markdown-body .highlight .pl-eoi,
.markdown-body .highlight .pl-sf,
.markdown-body .highlight .pl-smc {
color: #d12089;
}

.markdown-body .highlight .pl-ens,
.markdown-body .highlight .pl-eoai,
.markdown-body .highlight .pl-kos,
.markdown-body .highlight .pl-mh .pl-pdh,
.markdown-body .highlight .pl-mp,
.markdown-body .highlight .pl-pde,
.markdown-body .highlight .pl-stp {
color: #458;
}

.markdown-body .highlight .pl-enti {
color: #d12089;
font-weight: bold;
}

.markdown-body .highlight .pl-cce,
.markdown-body .highlight .pl-enc,
.markdown-body .highlight .pl-kou,
.markdown-body .highlight .pl-mq {
color: #f93;
}

.markdown-body .highlight .pl-mp1 .pl-sf {
color: #458;
font-weight: bold;
}

.markdown-body .highlight .pl-cos,
.markdown-body .highlight .pl-ent,
.markdown-body .highlight .pl-md,
.markdown-body .highlight .pl-mdhf,
.markdown-body .highlight .pl-ml,
.markdown-body .highlight .pl-pdc1,
.markdown-body .highlight .pl-pds,
.markdown-body .highlight .pl-s1,
.markdown-body .highlight .pl-scp,
.markdown-body .highlight .pl-sol {
color: #df5000;
}

.markdown-body .highlight .pl-c1,
.markdown-body .highlight .pl-cn,
.markdown-body .highlight .pl-pse,
.markdown-body .highlight .pl-pse .pl-s2,
.markdown-body .highlight .pl-vi {
color: #a31515;
}

.markdown-body .highlight .pl-mb,
.markdown-body .highlight .pl-pdb {
color: #df5000;
font-weight: bold;
}

.markdown-body .highlight .pl-mi,
.markdown-body .highlight .pl-pdi {
color: #6e5494;
font-style: italic;
}

.markdown-body .highlight .pl-ms1 {
background-color: #f5f5f5;
}

.markdown-body .highlight .pl-mdh,
.markdown-body .highlight .pl-mdi {
font-weight: bold;
}

.markdown-body .highlight .pl-mdr {
color: #0086b3;
font-weight: bold;
}

.markdown-body .highlight .pl-s2 {
color: #333;
}

.markdown-body .highlight .pl-ii {
background-color: #df5000;
color: #fff;
}

.markdown-body .highlight .pl-ib {
background-color: #f93;
}

.markdown-body .highlight .pl-id {
background-color: #a31515;
color: #fff;
}

.markdown-body .highlight .pl-iu {
background-color: #b4b7b4;
}

.markdown-body .highlight .pl-mo {
color: #969896;
}

.markdown-body .task-list-item {
list-style-type: none;
}

.markdown-body .task-list-item+.task-list-item {
margin-top: 3px;
}

.markdown-body .task-list-item input {
float: left;
margin: 0.3em 0 0.25em -1.6em;
vertical-align: middle;
}

模块化的 WebApi 服务，最核心的东西就是这货了：负责请求 URL 和控制器类型的映射 —— 简单来说就是红娘，不认识的话，小伙子你别想讨到媳妇儿了。

系统内置的缺省 WebApi 控制器发现工厂，只能从路由信息中获得控制器和动作，要获取自定义的路由信息，只能通过重写控制器获取工厂 IHttpControllerSelector 来解决。按照第一章中定下的规则，使用 {module}/{controller}/{action}/{id} 路由规则，我们需要为路由参数额外读取一个 module 参数。

注：id 变量并不由控制器获取工厂使用，在实际使用中由 Action 相关类映射：一个很明显的例子就是 WebApi 2 的 Attribute 映射。

话说回来，也不一定必须使用我定下这套规则，确保你能访问控制器即可。在这里简要说一下 IHttpControllerSelector 接口两大方法的作用：

  1. GetControllerMapping 用于获取路由规则和控制器类型的关系映射列表。
  2. SelectController 用于根据路由规则获取对应的控制器类型。

首先说一下 GetControllerMapping 方法：从当前加载的所有程序集中，获取得到符合条件的所有控制器类型，然后依据 {module}/{controller}/{action}/{id} 路由规则，从请求 URL 地址中获取对应变量的值，拼接形成缓存键后，添加到字典中。

根据《WebApi 插件式构建方案：发现并加载程序集》这一章定下的配置文件，是不包含 name 属性的（即 module 路由变量），我们需要为其扩展，扩展后的结果如下（这里只考虑在基础配置上扩展）：

<?xml version="1.0" encoding="UTF-8"?>

  <configuration enabled="true">

    <name>Authorization</name>

    <description>授权支持插件</description>

    <assemblies>

      <add type="relative">bin/Intime.AuthorizationService.dll</add>

      <add type="relative">bin/Intime.AuthorizationService.Services.dll</add>

      <add type="relative">bin/Intime.AuthorizationService.Data.dll</add>

      <add type="relative">bin/Intime.AuthorizationService.Data.Repository.dll</add>

    </assembiles>

</configuration>

在填充路由规则和控制器类型的关系映射时，读取 name 到路由变量 module 中，生成缓存项的键 Key。下面是填充逻辑真实代码：

注：下面这段代码，返回的字典中，键（string 类型）必须是不区分大小写的，否则 Http 请求地址大小写不同时找不到控制器。

private Dictionary<string, HttpControllerDescriptor> InitializeControllerDictionary()

{

    var dictionary = new Dictionary<string, HttpControllerDescriptor>(StringComparer.OrdinalIgnoreCase);

<span class="pl-k">foreach</span> (<span class="pl-k">var</span> item <span class="pl-k">in</span> DynamicModule.DefaultInstance.Modules)

    item.Configuration = <span class="pl-s">new</span> NamedPluginConfiguration(item.Configuration);

<span class="pl-k">var</span> types = _configuration.Services.GetHttpControllerTypeResolver().GetControllerTypes(_configuration.Services.GetAssembliesResolver());

<span class="pl-k">foreach</span> (<span class="pl-k">var</span> type <span class="pl-k">in</span> types)

{

    <span class="pl-k">var</span> moduleName = <span class="pl-st">string</span>.Empty;

    <span class="pl-k">var</span> module = DynamicModule.DefaultInstance.Modules.FirstOrDefault(p =&gt; p.Assemblies.Contains(type.Assembly));

    <span class="pl-k">if</span> (module != <span class="pl-c1">null</span>)

        moduleName = ((NamedPluginConfiguration)module.Configuration).Name;

    <span class="pl-k">var</span> segments = type.Namespace.Split(Type.Delimiter);

    <span class="pl-k">var</span> controllerName = type.Name.Remove(type.Name.Length - DefaultHttpControllerSelector.ControllerSuffix.Length);

    <span class="pl-k">var</span> key = String.Format(CultureInfo.InvariantCulture, <span class="pl-s1"><span class="pl-pds">"</span>{0}.{1}<span class="pl-pds">"</span></span>, segments[segments.Length - <span class="pl-c1">1</span>], controllerName);

    <span class="pl-k">if</span> (!<span class="pl-st">string</span>.IsNullOrWhiteSpace(moduleName))

        key = String.Format(CultureInfo.InvariantCulture, <span class="pl-s1"><span class="pl-pds">"</span>{0}.{1}<span class="pl-pds">"</span></span>, moduleName, key);

    <span class="pl-k">if</span> (dictionary.Keys.Contains(key))

        _duplicates.Add(key);

    <span class="pl-k">else</span>

        dictionary[key] = <span class="pl-s">new</span> HttpControllerDescriptor(_configuration, type.Name, type);

}

<span class="pl-k">foreach</span> (<span class="pl-k">var</span> item <span class="pl-k">in</span> _duplicates)

    dictionary.Remove(item);

<span class="pl-k">return</span> dictionary;


}

需要注意的是 NamedPluginConfiguration 类：我采用了修饰模式对原始配置进行了扩展。真实代码中，上一节的 AppConfig 也使用了这种方式，好处是：后续在有扩展需要在配置文件中添加信息时，可以很方便的读取而不需要另开炉灶。推荐各位在配置文件的读取上也使用这种设计模式。

上面说完了填充映射关系，下面继续说 SelectController 方法，也就是获取映射关系。获取映射关系就是根据客户端传过来的路由变量，根据填充时的规则引擎，重新生成映射关系的键，找到对应的控制器，再进行下一步操作。真实代码如下：

public HttpControllerDescriptor SelectController(HttpRequestMessage request)

{

    IHttpRouteData routeData = request.GetRouteData();

    if (routeData == null)

        throw new HttpResponseException(HttpStatusCode.NotFound);

<span class="pl-k">var</span> moduleName = routeData.GetRouteVariable(ModuleKey);

<span class="pl-st">string</span> namespaceName = routeData.GetRouteVariable(NamespaceKey);

<span class="pl-k">if</span> (namespaceName == <span class="pl-c1">null</span>)

    <span class="pl-k">throw</span> <span class="pl-s">new</span> HttpResponseException(HttpStatusCode.NotFound);

<span class="pl-st">string</span> controllerName = routeData.GetRouteVariable(DefaultHttpControllerSelector.ControllerSuffix);

<span class="pl-k">if</span> (controllerName == <span class="pl-c1">null</span>)

    <span class="pl-k">throw</span> <span class="pl-s">new</span> HttpResponseException(HttpStatusCode.NotFound);

<span class="pl-st">string</span> key = String.Format(CultureInfo.InvariantCulture, <span class="pl-s1"><span class="pl-pds">"</span>{0}.{1}<span class="pl-pds">"</span></span>, namespaceName, controllerName);

<span class="pl-k">if</span> (!<span class="pl-st">string</span>.IsNullOrWhiteSpace(moduleName))

    key = String.Format(CultureInfo.InvariantCulture, <span class="pl-s1"><span class="pl-pds">"</span>{0}.{1}<span class="pl-pds">"</span></span>, moduleName, key);

HttpControllerDescriptor controllerDescriptor;

<span class="pl-k">if</span> (_controllers.Value.TryGetValue(key, out controllerDescriptor))

    <span class="pl-k">return</span> controllerDescriptor;

<span class="pl-k">if</span> (_duplicates.Contains(key))

    <span class="pl-k">throw</span> <span class="pl-s">new</span> HttpResponseException(request.CreateErrorResponse(HttpStatusCode.InternalServerError, <span class="pl-s1"><span class="pl-pds">"</span>有多个控制器符合这个请求！<span class="pl-pds">"</span></span>));

<span class="pl-k">else</span>

    <span class="pl-k">throw</span> <span class="pl-s">new</span> HttpResponseException(HttpStatusCode.NotFound);


}

相信用心看到这里的人，心里已经隐隐明白了写什么。留个作业来检验下你的成果吧：如果要针对同一个功能，开发两个版本，此时该如何修改呢？

提示一下：在这两个方法里面加些东西就好了。实际并没有标准答案，功能实现了就行，下一篇文章我会写几种实现，需要的拿去就好。