How to set filter for FileSystemWatcher for multiple file types?

Question

Everywhere I find these two lines of code used to set filter for file system watcher in samples provided..

FileSystemWatcher watcher = new FileSystemWatcher(         


        

Answer 1

You can't do that. The Filter property only supports one filter at a time. From the documentation:

Use of multiple filters such as *.txt|*.doc is not supported.

You need to create a FileSystemWatcher for each file type. You can then bind them all to the same set of FileSystemEventHandler:

string[] filters = { "*.txt", "*.doc", "*.docx", "*.xls", "*.xlsx" };
List watchers = new List();

foreach(string f in filters)
{
    FileSystemWatcher w = new FileSystemWatcher();
    w.Filter = f;
    w.Changed += MyChangedHandler;
    watchers.Add(w);
}