Sometime you might need to monitor changes like files added, deleted, renamed for particular folder. To do so, .net provides
FileSystemWatcher class to monitor such kind of activity for particular folder
or file.
FileSystemWatcher class provides some events which are fired
when some action done to the folder like file created, deleted, renamed
etc. You can also specify filter to file system watcher if you want to watch only text
file or music files etc. It also provides an option to include subdirectories to
watch or monitor.
Let’s have a look on below code snippet
void FileSystemWatcherDemo_Loaded(object
sender, RoutedEventArgs e)
{
//creates an instance of FileSystemWatcher
FileSystemWatcher watcher = new FileSystemWatcher();
//set folder or file path to watch
watcher.Path = @"D:\Temp\Test";
//watches txt files only
watcher.Filter = "*.txt";
//enable watching subdirectories also
watcher.IncludeSubdirectories = true;
watcher.Created += new FileSystemEventHandler(watcher_Created);
watcher.Deleted
+= new FileSystemEventHandler(watcher_Deleted);
watcher.Renamed += new RenamedEventHandler(watcher_Renamed);
watcher.Changed += new FileSystemEventHandler(watcher_Changed);
//starts watching/monitoring folder or file
watcher.EnableRaisingEvents = true;
}
void watcher_Changed(object
sender, FileSystemEventArgs e)
{
Console.WriteLine("File
changed - {0}, change type - {1}", e.Name, e.ChangeType);
}
void watcher_Renamed(object
sender, RenamedEventArgs e)
{
Console.WriteLine("File
renamed - old name - {0}, new name - {1}", e.OldName, e.Name);
}
void watcher_Deleted(object
sender, FileSystemEventArgs e)
{
Console.WriteLine("File
deleted - {0}", e.Name);
}
void watcher_Created(object
sender, FileSystemEventArgs e)
{
Console.WriteLine("File
created - {0}, path - {1}", e.Name, e.FullPath);
}
Output –
File created - Text2.txt, path -
D:\Temp\Test\Text2.txt
File created - Text1.txt, path - D:\Temp\Test\Text1.txt
File renamed - old name - Text2.txt, new name -
Text3.txt
File deleted - Text3.txt
As per above code, I have chosen Test folder to monitor file
system changes. After running this application, if I add, delete, rename any
text file to this folder, it will notify FileSystemEvent to raise respective
event and the code written in respective event handler will execute.
See Also -
