c# - File.Delete the process cannot access the file because it is being used by another process -

public bool downloadmp3file (downloadedmp3 mp3) {         webclient client = new webclient ();         string filepath = "";         bool wasdownload = false;         try {               string song = mp3.songname;             filepath = @"mp3\" + song + ".mp3";             if (file.exists (filepath)) {                 file.delete (filepath);             }              datetime trycountnow = datetime.now;              client = new webclient ();             client.downloadfileasync (new uri (mp3.url), filepath);             client.downloadprogresschanged += client_downloadprogresschanged;             client.downloadfilecompleted += client_downloadfilecompleted;             datetime start = datetime.now;             bool notdownload = false;             downloadcomplete = false;             while (!downloadcomplete) {                 datetime = datetime.now;                 timespan ts = - start;                 int min = ts.minutes;                 int sec = ts.seconds;                 if (10 < sec && 0 == downloadprogress) {                     notdownload = true;                     client.cancelasync ();                     break;                 }                 if (min == 1) {                     notdownload = true;                     client.cancelasync ();                     break;                 }                 thread.sleep (30);             }             if (!notdownload) {                 client.cancelasync ();                 client.openread (mp3.url);                 int downloadedfilesize = convert.toint32 (client.responseheaders["content-length"]);                 fileinfo localfile = new fileinfo (filepath);                 if (localfile.length == downloadedfilesize) {                     wasdownload = true;                 }             }         }         catch {             downloadprogress = 0;             downloadcomplete = false;         }         {             client.cancelasync ();             client.dispose ();             downloadcomplete = false;             downloadprogress = 0;             gc.collect ();             if (!wasdownload) {                 if (file.exists (filepath)) {                     filesecurity fs = file.getaccesscontrol (filepath);                     file.delete (filepath);                 }             }             application.current.dispatcher.begininvoke (             dispatcherpriority.background,             new action (() =>                 mainwindow.label3.content = ""             ));         }         return wasdownload;     } 

please help! exception:

file.delete process cannot access file because being used process

i can't find out why (i disposed webclient).

your code suggests you're getting "file being used" exception on file newly downloaded. many anti-virus programs automatically scan newly created and/or newly downloaded files, , may delay closing file handle until scan done.

if problem, there's nothing more can close file on time. can either switch different anti-virus doesn't keep files locked during scans, or can implement delay+retry loop when trying use file that's been closed.