如何使用C#向券商接口发送带Cookie和Payload的下单请求

以下两种实现方式可根据你使用的.NET版本选择：

前置准备 #

首先定义和请求Payload对应的实体类，方便序列化生成JSON：

public class OrderPostRequest
{
    public bool IsSymbolCautionAgreement { get; set; }
    public bool CautionAgreementSelected { get; set; }
    public bool IsSymbolSepahAgreement { get; set; }
    public bool SepahAgreementSelected { get; set; }
    public int FinancialProviderId { get; set; }
    public string isin { get; set; }
    public int maxShow { get; set; }
    public int minimumQuantity { get; set; }
    public int orderCount { get; set; }
    public int orderId { get; set; }
    public decimal orderPrice { get; set; }
    public int orderSide { get; set; }
    public int orderValidity { get; set; }
    public string orderValiditydate { get; set; }
    public int shortSellIncentivePercent { get; set; }
    public bool shortSellIsEnabled { get; set; }
}

如果用Newtonsoft.Json序列化可以直接用这个类，如果用System.Text.Json记得按需配置序列化规则，避免驼峰/帕斯卡命名不匹配的问题。

方案1：使用HttpClient（推荐，适用于.NET Core 2.0+、.NET 5+所有新版本） #

HttpClient是.NET官方目前推荐的HTTP客户端，性能和易用性都优于HttpWebRequest，代码示例如下：

using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;

// 注意：HttpClient全局初始化一次即可，不要每次请求都new
private static readonly HttpClient _httpClient = new HttpClient();

public async Task SendOrderRequestAsync()
{
    // 1. 构造请求数据
    var orderReq = new OrderPostRequest
    {
        IsSymbolCautionAgreement = false,
        CautionAgreementSelected = false,
        IsSymbolSepahAgreement = false,
        SepahAgreementSelected = false,
        FinancialProviderId = 1,
        isin = "IRT1PLSH0001",
        maxShow = 0,
        minimumQuantity = 0,
        orderCount = 1000,
        orderId = 0,
        orderPrice = 82870,
        orderSide = 65, // 买卖方向，65对应买入，可根据券商规则调整
        orderValidity = 74,
        orderValiditydate = null,
        shortSellIncentivePercent = 0,
        shortSellIsEnabled = false
    };

    // 2. 序列化为JSON
    var json = JsonSerializer.Serialize(orderReq);
    var content = new StringContent(json, Encoding.UTF8, "application/json");

    // 3. 配置请求头，和抓包拿到的保持一致
    _httpClient.DefaultRequestHeaders.Clear();
    _httpClient.DefaultRequestHeaders.Add("authorization", "BasicAuthentication ca4f8b23-2921-4f51-ab7c-ed9fcb04bb4d");
    _httpClient.DefaultRequestHeaders.Add("origin", "https://www.mofidonline.com");
    _httpClient.DefaultRequestHeaders.Referrer = new Uri("https://www.mofidonline.com/");
    _httpClient.DefaultRequestHeaders.UserAgent.ParseAdd("Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.82 Safari/537.36");
    _httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("*/*"));
    _httpClient.DefaultRequestHeaders.AcceptEncoding.ParseAdd("gzip, deflate, br");
    _httpClient.DefaultRequestHeaders.AcceptLanguage.ParseAdd("en-US,en;q=0.9,fa;q=0.8");

    try
    {
        // 4. 发送POST请求
        var response = await _httpClient.PostAsync("https://api2.mofidonline.com/Web/V1/Order/Post", content);
        // 确保请求成功
        response.EnsureSuccessStatusCode();
        // 读取响应内容
        var responseStr = await response.Content.ReadAsStringAsync();
        Console.WriteLine($"请求成功，响应内容：{responseStr}");
    }
    catch (HttpRequestException ex)
    {
        Console.WriteLine($"请求失败，错误信息：{ex.Message}");
    }
}

方案2：使用HttpWebRequest（兼容.NET Framework等旧版本框架） #

using System.IO;
using System.Net;
using System.Text;
using Newtonsoft.Json; // 也可以用System.Text.Json

public void SendOrderRequestWithHttpWebRequest()
{
    // 1. 构造请求对象
    var request = (HttpWebRequest)WebRequest.Create("https://api2.mofidonline.com/Web/V1/Order/Post");
    request.Method = "POST";

    // 2. 配置请求头
    request.Headers.Add("authorization", "BasicAuthentication ca4f8b23-2921-4f51-ab7c-ed9fcb04bb4d");
    request.Headers.Add("origin", "https://www.mofidonline.com");
    request.Referer = "https://www.mofidonline.com/";
    request.UserAgent = "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.82 Safari/537.36";
    request.Accept = "*/*";
    request.Headers.Add("Accept-Encoding", "gzip, deflate, br");
    request.Headers.Add("Accept-Language", "en-US,en;q=0.9,fa;q=0.8");
    request.ContentType = "application/json";

    // 3. 构造请求体
    var orderReq = new OrderPostRequest
    {
        IsSymbolCautionAgreement = false,
        CautionAgreementSelected = false,
        IsSymbolSepahAgreement = false,
        SepahAgreementSelected = false,
        FinancialProviderId = 1,
        isin = "IRT1PLSH0001",
        maxShow = 0,
        minimumQuantity = 0,
        orderCount = 1000,
        orderId = 0,
        orderPrice = 82870,
        orderSide = 65,
        orderValidity = 74,
        orderValiditydate = null,
        shortSellIncentivePercent = 0,
        shortSellIsEnabled = false
    };
    var json = JsonConvert.SerializeObject(orderReq);
    var byteData = Encoding.UTF8.GetBytes(json);
    request.ContentLength = byteData.Length;

    // 4. 写入请求体
    using (var reqStream = request.GetRequestStream())
    {
        reqStream.Write(byteData, 0, byteData.Length);
    }

    try
    {
        // 5. 获取响应
        using (var response = (HttpWebResponse)request.GetResponse())
        using (var reader = new StreamReader(response.GetResponseStream()))
        {
            var responseStr = reader.ReadToEnd();
            Console.WriteLine($"请求成功，响应内容：{responseStr}");
        }
    }
    catch (WebException ex)
    {
        using (var reader = new StreamReader(ex.Response.GetResponseStream()))
        {
            var errorStr = reader.ReadToEnd();
            Console.WriteLine($"请求失败，错误信息：{ex.Message}，错误响应：{errorStr}");
        }
    }
}

注意事项 #

• 抓包拿到的authorization是身份校验凭证，会定期过期，实际使用时需要先模拟登录券商网站获取最新的有效凭证，不能直接使用示例中的值
• 委托参数如证券代码isin、委托数量orderCount、委托价格orderPrice、买卖方向orderSide等需要根据你的实际交易需求修改
• 券商接口通常有请求频率限制、风控校验规则，异常高频请求可能会导致账号被限制使用，请务必遵守券商的使用规则
• 如果请求失败，优先重新抓包核对请求头、请求体字段是否有更新，是否有新增的校验参数

内容的提问来源于stack exchange，提问作者Ali.s