跨域调用WebApi

using Libaray.DAL.Services;
using Libaray.Models.Entities;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;

namespace Libaray.WebApi.Controllers
{
    /// <summary>
    /// 图书信息
    /// </summary>
    public class BookController : ApiController
    {
        BookService BookDAL = new BookService();

        /// <summary>
        /// 查询所有图书信息
        /// </summary>
        /// <returns></returns>
        public IQueryable<BookModel> Get()
        {
            return BookDAL.FindList<BookModel>().AsQueryable();
        }

        /// <summary>
        /// 查询制定Id的图书信息
        /// </summary>
        /// <param name="id">图书Id</param>
        /// <returns>查询到的图书信息</returns>
        public BookModel Get(string id)
        {
            Guid BookId = Guid.Parse(id);
            return BookDAL.Find(u => u.BookId == BookId);
           
        }
    }
}

 <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>
    <httpProtocol>  <!-- 重点开始 -->
    <customHeaders>
      <add name="Access-Control-Allow-Origin" value="*" />
      <add name="Access-Control-Max-Age" value="30"/>
      <add name="Access-Control-Allow-Methods" value="GET,POST,OPTIONS"/>
      <add name="Access-Control-Allow-Headers" value="Content-Type, Accept" />
    </customHeaders>
  </httpProtocol>  <!-- 重点结束 -->
  </system.webServer>

@{
    ViewBag.Title = "FindBook";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>FindBook</h2>

<div class="table-responsive">
    <table class="table table-striped table-hover">
        <thead>
            <tr>
                <td>Book Name</td>
                <td>Author</td>
            </tr>
        </thead>
        <tbody id="tb">
           
        </tbody>
    </table>
</div>

<script type="text/javascript">
    $(function () {
        $.getJSON("http://localhost:50159/api/book", function (data) {
            $.each(data, function (key, item) {
                $("#tb").append("<tr><td>" + item.BookName + "</td>" + "<td>" + item.Author + "</td></tr>");
            });
        });
    })
</script>