How to reuse FtpWebRequest and close it until all operations finished

Question

User-86041214 posted

Hi:

I have an problem about how to reuse FtpWebRequest and close it until all operations finished.

The following is the example of the FtpWebRequest in code project:

https://www.codeproject.com/Tips/443588/Simple-Csharp-FTP-Class 

The main problem is when the FtpWebRequest opening and connecting to FTP server, and when to 

Close it when all operations are finished. Like the following scenarios:

Construct a FtpWebRequest class, like ftp object, then:

1.ftp.connect, 2.ftp.checkDirectoryExist, 3.ftp.checkFileExist,...

and finally, ftp.close;

Is there any instruction or suggestion for that, thanks a lot.

Answer 1

User-335504541 posted

Hi abramhum.c.l,

Do you want to know how to open and close the FtpWebRequest?

If so, please try to refer to the following code:

            FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://www.contoso.com/test.htm");
            request.Method = WebRequestMethods.Ftp.DownloadFile;

            // This example assumes the FTP site uses anonymous logon.  
            request.Credentials = new NetworkCredential("anonymous", "[e-mail]");

            // Check file exist 
            try
            {
                FtpWebResponse response = (FtpWebResponse)request.GetResponse();
                Stream responseStream = response.GetResponseStream();
                StreamReader reader = new StreamReader(responseStream);
                Console.WriteLine(reader.ReadToEnd());
                Console.WriteLine("Download Complete, status {0}", response.StatusDescription);
                reader.Close();
                response.Close();
            }
            catch (WebException ex)
            {
                FtpWebResponse response = (FtpWebResponse)ex.Response;
                if (response.StatusCode == FtpStatusCode.ActionNotTakenFileUnavailable)
                {
                    //File not exist
                }                   
            }

And here is the reference:

https://docs.microsoft.com/en-us/dotnet/framework/network-programming/how-to-download-files-with-ftp

https://stackoverflow.com/questions/347897/how-to-check-if-file-exists-on-ftp-before-ftpwebrequest

Best Regards,

Billy

Answer 2

User-86041214 posted

NO, I hope to know when the FtpWebRequest open connection, and if the connection exist, 

could I add multiple operations, like checkfileExist, AddFile,DownloadFile, ..and so on.

And then finally, close the connection, set the FtpWebRequest object to null.

But he problem is all the examples I found didn't talk about that, and some articles 

say it can't be this way. So, I hope to find the correct answer, and make sure if 

FtpWebRequest can do it. Thanks.

Answer 3

User-335504541 posted

Hi abramhum.c.l,

NO, I hope to know when the FtpWebRequest open connection, and if the connection exist, 

could I add multiple operations, like checkfileExist, AddFile,DownloadFile, ..and so on.

The connection open when the

FtpWebResponse response = (FtpWebResponse)request.GetResponse();

executed.

If you want to add file or download file, you need to set the request.Method before open the connection.

For example:

 FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://xxx.xxx.xxx.xxx:21/test.txt");
 request.Method = WebRequestMethods.Ftp.DownloadFile;

https://docs.microsoft.com/en-us/dotnet/api/system.net.ftpwebrequest.method?view=netframework-4.7.1

And if you want to close the connection, please try to use:

response.Close();

Best Regards,

Billy

Answer 4

User-86041214 posted

Thanks. And could I do multiple methods before close()?

Answer 5

User-335504541 posted

Hi abramhum.c.l,

And could I do multiple methods before close()?

I'm afraid you can't. You need to use 

 (FtpWebRequest)WebRequest.Create("ftp://xxx.xxx.xxx.xxx:21/xxx.xx")

to create multiple requests for multiple methods.

Best Regards,

Billy

Answer 6

User-86041214 posted

Thanks for your help.

Answer 7

User-86041214 posted

is there any other way micsoft given can do that? Thanks.