Process cannot access file because its used by another process

Question

So I'm getting exception "Process cannot access file because its used by another process.

The exception will show when i call this particular method:

public async static Task<bool> DownloadFileFromFTP(string PathToFile, string AppName)
{
    return await Task.Run(() => {
       if (File.Exists("settings.xml"))
       {
           XmlSerializer xs = new XmlSerializer(typeof(Information));
           FileStream read = new FileStream("settings.xml", FileMode.Open, FileAccess.Read, FileShare.Read);
           Information info = (Information)xs.Deserialize(read);

           try
           {
               FtpClient client = new FtpClient(info.HDSynologyIP);
               string a = info.FtpPassword;
               string FTPPassword = EncryDecryptor.Decrypt(a);
               client.Credentials = new NetworkCredential(info.FtpUsername, FTPPassword);
               client.Connect();

               bool finish = client.DownloadFile(@info.Downloads + "\\" + AppName, PathToFile, FtpLocalExists.Overwrite, FluentFTP.FtpVerify.Retry);
               if (finish == true)
               {
                   client.Disconnect();
                   read.Close();
                   return true;
               }
               else
               {
                   client.Disconnect();
                   read.Close();
                   return false;
               }

           }
           catch (Exception ex)
           {
               MessageBox.Show(ex.ToString());
               read.Close();
           }
           read.Close();
       }
       else
       {
           MessageBox.Show("Missing settings.xml file");
           return false;
       }
       return false;
   });
}

And call it in another class like this:

await General_Functions.DownloadFileFromFTP("Ultra_Script/Basic_SW/Adobe_Reader.exe", "Adobe_Reader.exe");

It wasn't asynchronous before but i had to remake it into asynchronous method. But i think I'm closing reader and client correctly. Can it be problem of async method? Because i don't had this problem before i made it asynchronous.

Can someone explain what I'm doing wrong?

Note, I am using FluentFTP from https://github.com/robinrodricks/FluentFTP .

I can't see a huge benefit of using `await` there, given you are spinning up a new `Task` anyway. What makes you think it is useful here? — mjwills, Jul 30 '19 at 13:15
Is `Adobe_Reader.exe` already running? Did you check Task Manager? — mjwills, Jul 30 '19 at 13:19
@mjwills Btw im learning how async method works so im trying to do everything in async just for purpose of learning. But doesnt it make app more responsible when doing tasks? No Adobe_Reader is not running at all there is no code who will open it, just download it from ftp repozitary — Johny Corbie, Jul 30 '19 at 13:20
@Renat, here is the whole exception trac: https://i.imgur.com/yVk4ONr.png — Johny Corbie, Jul 30 '19 at 13:25

score 0 · Answer 1 · answered Jul 30 '19 at 13:23

0

use using to terminate the file reader process

using(FileStream read = new FileStream("settings.xml", FileMode.Open, FileAccess.Read, FileShare.Read))
{ 
    // your code here.....
}

answered Jul 30 '19 at 13:23

Ahmad Alkaraki

106
1
6

Didnt help :-(. – Johny Corbie Jul 30 '19 at 15:00

Process cannot access file because its used by another process

1 Answers1