System.IO.File.Copy Throws IOException -

i trying copy files:

private void docopy() {     string[] files = directory.getfiles(application.startuppath + "\\app_data", "*.*", searchoption.alldirectories);      string sftptoreadfilefrom = "ftp://<user>:<pass>@mysite.tk/updates/app_data/";     string spathtowritefileto = application.startuppath + "\\app_data";      webclient webclient = new webclient();     webclient.credentials = new networkcredential("user", "pass");      foreach (string s in files)     {         string filename = path.getfilename(s);         string destfile = path.combine(spathtowritefileto, filename);         byte[] filedata = webclient.downloaddata(sftptoreadfilefrom + filename); //shows correct bytes          file.copy(s, destfile, true);     } } 

the exact error is: process cannot access file 'c:\applauncher\applauncher\bin\debug\app_data\firstfile' because being used process.

i followed 'msdn how to' here: http://msdn.microsoft.com/en-us/library/cc148994.aspx

if finds immediate red flags please let me know.

this how see it:

you want download file ftp server , write local disk. doing taking files in source-directory targets, won't work @ all. if files exist there, if can acquire file names there. (hence exception)

here must do

connect ftp, acquire files there (their bytes) , create files on disk.

private void docopy() {     //string[] files = directory.getfiles(application.startuppath + "\\app_data", "*.*", searchoption.alldirectories);      //acquire filenames ftp-server instead of local disk!      string sftptoreadfilefrom = "ftp://<user>:<pass>@mysite.tk/updates/app_data/";     string spathtowritefileto = application.startuppath + "\\app_data";      webclient webclient = new webclient();     webclient.credentials = new networkcredential("user", "pass");      foreach (string s in files)     {         string filename = path.getfilename(s); //create file names based on ftp-server         string destfile = path.combine(spathtowritefileto, filename);         byte[] filedata = webclient.downloaddata(sftptoreadfilefrom + filename); //shows correct bytes          //file.copy(s, destfile, true); rather use file.writeallbytes         file.writeallbytes(destfile, filedata);     } } 

see here example of file.writeallbytes.

the acquiring of filenames ftp not straightforward, though. there ftpwebrequest-class support you.