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c#filesystemwatcher

FileSystemWatcher Waiting

The following process remains waiting, while the file is present. I probably made ​​an error, but I don't see where.

System.IO.WaitForChangedResult result;
seeTransFile.WaitForChanged(System.IO.WatcherChangeTypes.Created);
string seeDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
System.IO.FileSystemWatcher watcher = new FileSystemWatcher(SynDir, fileName + @".md5");
result = watcher.WaitForChanged(System.IO.WatcherChangeTypes.Created);

Can you help me?

Solution

  • FileSystemWatcher will only trigger when the file is created/changed. Existing files are ignored.

    First start your FileSystemWatcher, then use Directory.GetFiles to get existing files.

    If you need to read the contents of files detected by FileSystemWatcher, I recommend you verify that the owner of the file has released all locks on it by using this code:

    try 
{
    // Attempts to open then close the file in RW mode, denying other users to place any locks.
    FileStream fs = File.Open(filepath, FileMode.Open, FileAccess.ReadWrite, FileShare.None);
    fs.Close();
    fileClosed = true; // success
}
catch (IOException) {}

    If a lock is present on the file, either wait for it to be released by its owner or put the file on a queue and retry later.