C# 计数未加载类型[ProjectName]。Web API项目上的WebAPI应用程序

我有一个使用Web.API的.Net Web应用程序。项目属性显示它正在使用.Net 4.5

在我的网页中，以下代码调用其中一个方法

                $.ajax({
                    type: 'POST',
                    url: '/Appointments/GetMissingKeys',
                    data:  $('#mrnList').val()                      
                }).done(function() {
                    alert('done!');
                }).fail(function (Status, errorThrown) {
                    alert('Error: ' + Status.status + ' - ' + Status.statusText);
                }).always(function () {
                    alert('All done or not');
                });

这反过来应该调用以下命令

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;

namespace MRNInput.Controllers
{
    public class AppointmentController : ApiController
    {
        [AcceptVerbs("Post")]
        [Route("Appointments/GetMissingKeys")]
        HttpResponseMessage GetMissingAppointmentKeys([FromBody]String MRNList)
        {
            HttpResponseMessage resp = null;

            resp = new HttpResponseMessage(HttpStatusCode.Accepted);
            return resp;
        }
    }
}

Server Error in '/' Application.
--------------------------------------------------------------------------------

Parser Error 
Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately. 

Parser Error Message: Could not load type 'MRNInput.WebApiApplication'.

Source Error: 


Line 1:  <%@ Application Codebehind="Global.asax.cs" Inherits="MRNInput.WebApiApplication" Language="C#" %>


Source File: /global.asax    Line: 1 

--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.18408 

当我检查status对象时，我得到一个内部服务器错误500，响应如下

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;

namespace MRNInput.Controllers
{
    public class AppointmentController : ApiController
    {
        [AcceptVerbs("Post")]
        [Route("Appointments/GetMissingKeys")]
        HttpResponseMessage GetMissingAppointmentKeys([FromBody]String MRNList)
        {
            HttpResponseMessage resp = null;

            resp = new HttpResponseMessage(HttpStatusCode.Accepted);
            return resp;
        }
    }
}

Server Error in '/' Application.
--------------------------------------------------------------------------------

Parser Error 
Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately. 

Parser Error Message: Could not load type 'MRNInput.WebApiApplication'.

Source Error: 


Line 1:  <%@ Application Codebehind="Global.asax.cs" Inherits="MRNInput.WebApiApplication" Language="C#" %>


Source File: /global.asax    Line: 1 

--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.18408 

现在除了错误页面中的.Net版本之外，我不明白为什么它不能加载最后一个类。如果是错误中报告的.Net版本，我如何才能让它在正确的.Net版本4.5下运行呢

选择构建菜单，然后选择“清洁解决方案”选项

---

这将消除“无法加载类型[ProjectName].WebAPI应用程序在Web API项目上”错误-由于找不到约会/GetMissingKeys，现在要处理路由问题：

进行以下更改：

namespace MRNInput.Controllers
{
    public class AppointmentController : ApiController
    {
        [HttpPost, Route("api/Appointments/GetMissingKeys")]
        public IHttpActionResult GetMissingAppointmentKeys([FromBody]string MRNList)
        {
            return Ok();
        }
    }
}

$.ajax({
   type: 'POST',
   url: '/api/Appointments/GetMissingKeys',
   data:  $('#mrnList').val() //ensure you have a value here,
   datatype: "json" //<-- note the additional property                     
})

我还建议将此添加到startup.cs中，以处理自动驼峰套管

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvc().Configure<MvcOptions>(options =>
    {
       options.OutputFormatters.OfType<JsonOutputFormatter>()
       .First()
       .SerializerSettings
       .ContractResolver = new CamelCasePropertyNamesContractResolver();
    });
}

---

注意，您的js api调用正在寻找约会，而您的控制器正在寻找约会。试试这个

[RoutePrefix("api/Appointments")]
public class AppointmentController : ApiController
{
    [AcceptVerbs("Post")]
    [Route("GetMissingKeys")]
    HttpResponseMessage GetMissingAppointmentKeys([FromBody]String MRNList)
    {
        HttpResponseMessage resp = null;

        resp = new HttpResponseMessage(HttpStatusCode.Accepted);
        return resp;
    }
}

---

如果你将你的api方法公开，会有什么不同吗？同样，这是正确的url，还是应该是api/Appoints/getmissingkeys？只是尝试了一下，仍然得到404错误。不确定这是否与页面位于站点的根目录而不是视图目录有关。出现错误的文本消息是{消息：未找到与请求URI匹配的HTTP资源。}找到与名为“约会”的控制器匹配的类型。}这是因为您的控制器是约会单数，而您调用的是约会复数。去掉api调用中的“s”。我投票关闭，因为OP用干净的解决方案解决了这个问题。Paul-请创建一个新问题，因为它找不到约会/GetMissingKey。如果你更新了你的问题，所有的答案都是无关的。