The purpose of this article is to address the lack of information that is available from the
FileSystemWatcher utility class.
The problem with the
FileSystemWatcher class is we don't know when exactly has the file copy completed in order to process the file?
Using the code
Monitor class wraps the
FileSystemWatcher's functionality. The
FileObject class encapsulates a newly copied file's general information as well as providing a method call that returns an output stream which can be manipulated.
private void SystemWatch()
FileSystemWatcher watcher = new FileSystemWatcher();
watcher.Path = ConfigurationInfo.ModulePath+
watcher.NotifyFilter = NotifyFilters.LastWrite |
watcher.Filter = "*.*";
watcher.Created += new FileSystemEventHandler(OnChanged);
watcher.Changed += new FileSystemEventHandler(OnChanged);
watcher.EnableRaisingEvents = true;
The next tricky bit is knowing when to start processing the file i.e. when has the file copy completed.
Someone else might come up with a better solution but in the RAD environment that I program in development speed and stability are very important. The trick is to user a SystemTimer which has a fairly low resource impact and increment the timer interval every time an IO event is fired. Obviously once the file copy has completed the interval will not be incremented and the timer will timeout.
private System.Timers.Timer LogTimer = new System.Timers.Timer();
public LogFileTimer(int tTime, string Name)
PollTime = tTime;
fileName = Name;
LogTimer.Elapsed += new ElapsedEventHandler(Timeup);
LogTimer.Interval = PollTime;
LogTimer.Enabled = true;
LogTimer.AutoReset = false;
Points of Interest
The big problem this solution solves is that large files copied into a monitored directory can only be processed once the copy or FTP has completed. I think the solution is neat but probably can be scaled down even further. I used these objects to convert a very large FTP'd flat file into XML.
This is my first article so go easy.
I studied IT in 1987 and have been working ever since in on projects that range from coding animation in pascal and assembler to writing secure internet banking web sites.
I live in South Africa and I think because of it's size we're required to do more for less which makes highly skilled in a wide range of skills and technologies.
I have the bonus of living in a coastal town so time away from computers is spent around the sea and in sunshine and nature.