c#下载微信跟支付宝交易账单

• 下载微信交易账单

                   //账单日期只能下载前一天的
				   string datetime = DateTime.Now.AddDays(-1).ToString("yyyy-MM-dd");
                    string body = "";
                    string URL = "/v3/bill/fundflowbill" + "?bill_date=" + datetime;
					//生成签名认证
                    var auth = BuildAuthAsync("GET", body, URL);
                    string Authorization = $"WECHATPAY2-SHA256-RSA2048 {
     auth}";
                    string bill_date = datetime;
                    string url = "https://api.mch.weixin.qq.com/v3/bill/fundflowbill";
                    url = url + "?" + "bill_date=" + bill_date.ToString();
                    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
                    request.Timeout = 20000;  //超时时间
                    request.Method = "GET";  //请求方式
                    request.KeepAlive = true;
                    request.Headers.Add("Authorization", Authorization);
                    request.Accept = "application/json";
                    request.UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36";
                    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                    string postContent = new StreamReader(response.GetResponseStream()).ReadToEnd();
                    JObject json = JObject.Parse(postContent);
                    var download_url = json["download_url"].ToString();
                    var hash_type = json["hash_type"].ToString();
                    var hash_value = json["hash_value"].ToString();
                    if (download_url != "")
                    {
   

                            int index = download_url.IndexOf(".com") + 4;
                            string downurl = download_url.Substring(index);
                            var Token = BuildAuthAsync("GET", body, downurl);
                            Token = $"WECHATPAY2-SHA256-RSA2048 {
     Token}";
                            string FilePath = "D:\\PublicDocumentsFile\\WaChat\\" + datetime + ".csv";
                            using (WebClient client = new WebClient())
                            {
   
                                client.Headers.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3");
                                client.Headers.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
                                client.Headers.Add("Authorization", Token);
                                // 发送GET请求下载文件  
                                byte[] fileData = client.DownloadData(download_url);
                                // 将文件保存到本地  
                                File.WriteAllBytes(FilePath, fileData