当一个接口需要调用多个其他服务的接口时，可以使用异步编程来实现并发调用，以提高效率

using System;
using System.Collections.Generic;
using System.Threading.Tasks;

public class OrderController
{
public async Task<OrderInfo> GetOrderInfo(int orderId)
{
// 并发调用多个接口
Task<UserInfo> getUserInfoTask = GetUserInfoAsync(orderId);
Task<ProductInfo> getProductInfoTask = GetProductInfoAsync(orderId);
Task<LogisticsInfo> getLogisticsInfoTask = GetLogisticsInfoAsync(orderId);
Task<List<ProductRecommendation>> getProductRecommendationsTask = GetProductRecommendationsAsync(orderId);

// 等待所有任务完成
await Task.WhenAll(getUserInfoTask, getProductInfoTask, getLogisticsInfoTask, getProductRecommendationsTask);

// 汇总数据
UserInfo userInfo = getUserInfoTask.Result;
ProductInfo productInfo = getProductInfoTask.Result;
LogisticsInfo logisticsInfo = getLogisticsInfoTask.Result;
List<ProductRecommendation> productRecommendations = getProductRecommendationsTask.Result;

// 构造订单信息对象
OrderInfo orderInfo = new OrderInfo
{
UserInfo = userInfo,
ProductInfo = productInfo,
LogisticsInfo = logisticsInfo,
ProductRecommendations = productRecommendations
};

return orderInfo;
}

private async Task<UserInfo> GetUserInfoAsync(int orderId)
{
// 调用用户信息接口，返回用户信息
// 例如：UserInfo userInfo = await UserService.GetUserInfoAsync(orderId);
return userInfo;
}

private async Task<ProductInfo> GetProductInfoAsync(int orderId)
{
// 调用商品详情接口，返回商品详情
// 例如：ProductInfo productInfo = await ProductService.GetProductInfoAsync(orderId);
return productInfo;
}

private async Task<LogisticsInfo> GetLogisticsInfoAsync(int orderId)
{
// 调用物流信息接口，返回物流信息
// 例如：LogisticsInfo logisticsInfo = await LogisticsService.GetLogisticsInfoAsync(orderId);
return logisticsInfo;
}

private async Task<List<ProductRecommendation>> GetProductRecommendationsAsync(int orderId)
{
// 调用商品推荐接口，返回商品推荐列表
// 例如：List<ProductRecommendation> productRecommendations = await ProductService.GetProductRecommendationsAsync(orderId);
return productRecommendations;
}
}

public class OrderInfo
{
public UserInfo UserInfo { get; set; }
public ProductInfo ProductInfo { get; set; }
public LogisticsInfo LogisticsInfo { get; set; }
public List<ProductRecommendation> ProductRecommendations { get; set; }
}

public class UserInfo
{
// 用户信息属性
}

public class ProductInfo
{
// 商品详情属性
}

public class LogisticsInfo
{
// 物流信息属性
}

public class ProductRecommendation
{
// 商品推荐属性
}