File.Move() Issue with FileSystemWatcher

Question

I am using the FileSystemWatcher method to watch a folder. When a file arrives it will move the file to a process folder. My problem is when a large file is put in the folder the move command errors with Unhandled Exception: System.IO.IOException: The process cannot access the file "c:	emp	est.zip" because it is being used by another process. Obviously the file has not finished copying to the directory. Is there an attribute on the file that I can check to see if it can be moved or is there a filter that I can use that will only trip the oncreated event after the file has completely copied to the folder.

Administrator · Answer

There are two way to react if the file was created. In the EventHandler of your Changed Event you can check the ChangeType. this.fWatcher.Changed += new System.IO.FileSystemEventHandler(this.FileWatcherFileChanged); protected void FileWatcherFileChanged(object sender, System.IO.FileSystemEventArgs e) { if(e.ChangeType == WatcherChangeTypes.Created) { // do something } else if(e.ChangeType == WatcherChangeTypes.Changed { // do something } } Second way is that you create a EventHandler for the Created Event. this.fWatcher.Created += new System.IO.FileSystemEventHandler(this.FileWatcherFileCreated); protected void FileWatcherFileCreated(object sender, System.IO.FileSystemEventArgs e) { if(e.ChangeType == WatcherChangeTypes.Created) { // do something } } In both cases you should check the e.ChangeType, cause for some operations more than only one eventHandler react. To prevent Exceptions check the Changetype and only process the needed one.

File.Move() Issue with FileSystemWatcher

Answers (1)