c# web api 无法从网络调用

Question

我有一个包含一些模型和 Controller 的web api解决方案。

这是我的模型的一个例子:

public class Category
{
    [Key]
    public int Id { get; set; }
    [Required]
    public string Name { get; set; }
}

这是他的 Controller :

public class CategoriesController : ApiController
{
    private FrigoWebServiceContext db = new FrigoWebServiceContext();

    // GET: api/Categories
    [HttpGet]
    public string GetCategories()
    {
        return JsonConvert.SerializeObject(db.Categories.ToList());
    }

    // GET: api/Categories/5
    [ResponseType(typeof(string))]
    public string GetCategory(int id)
    {
        Category category = db.Categories.Find(id);
        if (category == null)
        {
            return null;
        }

        string jsonCategory = JsonConvert.SerializeObject(category);
        return jsonCategory;
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            db.Dispose();
        }
        base.Dispose(disposing);
    }

    private bool CategoryExists(int id)
    {
        return db.Categories.Count(e => e.Id == id) > 0;
    }
}

现在，这是配置:

        config.Routes.MapHttpRoute(
            name: "GetId",
            routeTemplate: "api/{controller}/{id}"
            //defaults: new { id = RouteParameter.Optional }
        );
        config.Routes.MapHttpRoute(
            name: "GetAll",
            routeTemplate: "api/{controller}"
            //defaults: new { id = RouteParameter.Optional }
        );

但是调用以下网站我没有得到任何东西

注意:我使用 IIS 发布了带有“myAppName”路径名的 api

• http://localhost/myAppName/Api/CategoriesController
• http://localhost/myAppName/Api/CategoriesController/0
• http://localhost/myAppName/Api/Category
• http://localhost/myAppName/Api/Category/0
• http://localhost/myAppName/Api/CategoriesController/GetCategories
• http://localhost/myAppName/Api/Category/GetCategories
• http://localhost/myAppName/Api/Categories

但是这些都没有用

这是错误:

Error HTTP 404.0 - Not Found Desired resource has been removed, renamed or it's temporally unavaible

我从互联网上看到了一些问题，我尝试使用它们，但我不明白为什么这不起作用。

任何帮助将不胜感激，这是我第一次使用 WebApi

这是我的Web.Config

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <connectionStrings>
    <add name="FrigoWebServiceContext" connectionString= [***] />
  </connectionStrings>
  <appSettings></appSettings>
  <system.web>
    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" />
    <httpModules>
      <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" />
    </httpModules>
  </system.web>
  <system.webServer>
    <handlers>
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
    <validation validateIntegratedModeConfiguration="false" />
    <modules>
      <remove name="ApplicationInsightsWebTracking" />
      <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" preCondition="managedHandler" />
    </modules>
  </system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-9.0.0.0" newVersion="9.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701" />
      <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+" />
    </compilers>
  </system.codedom>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>
</configuration>

Answer 1

如果您没有使用 Route attribute指定/覆盖方法名称并且您没有在路由中指定默认方法名称，然后 Web API 使用默认操作动词 Get、Post、Put, Delete 作为方法名。这意味着您必须像这样更改方法:

仅查看方法名称更改，不要注意返回类型，这是我对您的示例代码的另一个提示。您应该让 Web API 框架使用配置的序列化程序，而不是返回字符串，而是默认返回 IHttpActionResult。为什么和如何超出这个问题的范围，但我不会通过将字符串作为方法签名的返回类型来延续不良做法。

public class CategoriesController : ApiController
{
  [HttpGet]
  public IHttpActionResult Get()

  // or to pass in an an int and return only 1 category
  [HttpGet]
  public IHttpActionResult Get(int id)

现在允许你这样调用你的 api

• /Api/Categories/
• 或者/Api/Categories/128用第二种方法

---

如果您想使用这 4 个方法名称(get/put/post/delete)以外的方法名称，那么您可以在 WebApiConfig.cs 中更改路由或使用 Route attribute .

对于 WebApiConfig.cs，您可以这样做:

config.Routes.MapHttpRoute(
    name: "Get",
    routeTemplate: "api/{controller}/{action}/{id}"
    defaults: new { id = RouteParameter.Optional }
);

现在允许你这样调用你的 api

• /Api/Categories/GetCategories/
• /Api/Categories/GetCategory/1234

---

如果你想使用 Route attribute你可以这样做:

[RoutePrefix("api/categories"]
public class CategoriesController : ApiController
{
  [HttpGet]
  [Route("")]
  public IHttpActionResult GetCategories()

  [HttpGet]
  [Route("{id:int}")]
  public IHttpActionResult GetCategory(int id)

现在允许你这样调用你的 api

• /Api/Categories/
• 或者/Api/Categories/128用第二种方法

---

编辑

根据下面的评论... 另见 HTTP 404 Page Not Found in Web Api hosted in IIS 7.5 .将 UrlRoutingModule 添加到 web.config 解决了这个问题，因为它是由那个和路由配置引起的。