Bing Maps REST API提供了基于HTTP请求的路线规划服务，可以使用C#语言来访问API并对路线进行优化，以下是一个示例：

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Web.Script.Serialization;

namespace BingMapsRestApiSample
{
    class Program
    {
        static void Main(string[] args)
        {
            string apiUrl = "http://dev.virtualearth.net/REST/v1/Routes/OptimizeMultiItinerary?";

            // 设置Bing Maps API密钥
            string apiKey = "Your API Key";

            // 添加路线点
            List waypoints = new List()
            {
                new Waypoint("Seattle, WA"),
                new Waypoint("Portland, OR"),
                new Waypoint("San Francisco, CA"),
                new Waypoint("Los Angeles, CA"),
                new Waypoint("Las Vegas, NV")
            };

            // 设置路线参数
            RouteOptions routeOptions = new RouteOptions()
            {
                Optimize = "distance",
                TravelMode = "driving",
                DistanceUnit = "mi"
            };

            // 配置请求URL
            string requestUrl = apiUrl + "waypoint." + Waypoint.FormatType + "=" +
                string.Join(",", waypoints) + "&" +
                routeOptions.ToString() + "&" +
                "key=" + apiKey;

            // 发送HTTP请求并获取响应
            HttpWebRequest request = WebRequest.CreateHttp(requestUrl);
            WebResponse response = request.GetResponse();
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
            string responseJson = reader.ReadToEnd();

            // 将JSON响应转换为对象
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            MultiItineraryRouteResponse routeResponse = serializer.Deserialize(responseJson);

            // 输出路线信息
            Console.WriteLine("Total route distance: {0} miles", routeResponse.ResourceSets[0].Resources[0].TravelDistance);
            Console.WriteLine("Total route time: {0} minutes", routeResponse.ResourceSets[0].Resources[0].TravelDuration);

            foreach (ItineraryItem item in routeResponse.ResourceSets[0].Resources[0].RouteLegs[0].ItineraryItems)
            {
                Console.WriteLine("From {0} to {1}: {2} miles, {3} minutes",
                    item.ManeuverPoint.Coordinates[0], item.ManeuverPoint.Coordinates[1],
                    item.TravelDistance, item.Travel