附加信息：基础连接已关闭：连接意外关闭

Question

我有以下代码。无论我如何尝试，它都无法连接。

 WebClient client = new WebClient();
 client.Credentials = new NetworkCredential(Login, Password);


ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

ServicePointManager.ServerCertificateValidationCallback =
 (sender, cert,chain,error) => true;


client.UploadFile("MyhttpsLink", WebRequestMethods.Ftp.UploadFile,"D:\\test.csv");

1：预期结果：我需要将该文件上传到我的FTP链接

2：实际结果：其他信息：基础连接已关闭：连接意外关闭。