ASP.NET将多部分/表单数据发送到Power Automate

[HttpPost]
public ActionResult UploadFile(HttpPostedFileBase file)
{
    // 检查文件是否存在
    if (file != null && file.ContentLength > 0)
    {
        // 保存文件到服务器
        var fileName = Path.GetFileName(file.FileName);
        var path = Path.Combine(Server.MapPath("~/Uploads"), fileName);
        file.SaveAs(path);

        // 构建Power Automate请求
        var url = "https://api.powerautomate.com/your-flow-endpoint";
        var request = (HttpWebRequest)WebRequest.Create(url);
        request.Method = "POST";

        // 添加文件和其他表单字段到请求
        using (var formData = new MultipartFormDataContent())
        {
            // 添加文件
            var fileContent = new StreamContent(file.InputStream);
            formData.Add(fileContent, "file", fileName);

            // 添加其他表单字段
            formData.Add(new StringContent("value1"), "field1");
            formData.Add(new StringContent("value2"), "field2");

            // 发送请求
            using (var client = new HttpClient())
            {
                var response = client.PostAsync(url, formData).Result;
                if (response.IsSuccessStatusCode)
                {
                    // 请求成功处理逻辑
                    return RedirectToAction("Success");
                }
                else
                {
                    // 请求失败处理逻辑
                    return RedirectToAction("Error");
                }
            }
        }
    }

    // 文件不存在处理逻辑
    return RedirectToAction("Error");
}