I have an app, listening for the *.log file in a chosen folder. I used FileSystemWatcher
.
But there is a problem. The other app responsible for making that file takes following steps:
And I can not change this behaviour.
So I made 2 FileSystemWatcher
s for *.gz, and *.txt files. Why? Because this app sometimes doesn't unpack the gz file, and sometimes doesn't rename the txt file to the final *.log file.
FileSystemWatcher2
catches txt file, then (in the most cases it is renamed to log in the next 1000ms) I need to wait some time to check if txt file exists (if not, it seems to be renamed to the final *.log file).
The question is, how to check if file exists without Thread.Sleep()
to prevent UI freeze?
I hope it is clear, if not I will try to describe it better. I think this is a complex problem.
Some code sample:
Watcher for gz file:
private void fileSystemWatcher_Created(object sender, FileSystemEventArgs e)
{
//this is for gz files in case if gz file is not unpacked automatically by other app
//I need to wait and check if gz was unpacked, if not, unpack it by myself,
//then txt watcher will catch that
Thread.Sleep(5000);
if (File.Exists(e.FullPath))
{
try
{
byte[] dataBuffer = new byte[4096];
using (System.IO.Stream fs = new FileStream(e.FullPath,
FileMode.Open,
FileAccess.Read))
{
using (GZipInputStream gzipStream = new GZipInputStream(fs))
{
string fnOut = Path.Combine(path_to_watcher,
Path.GetFileNameWithoutExtension(e.FullPath));
using (FileStream fsOut = File.Create(fnOut))
{
StreamUtils.Copy(gzipStream, fsOut, dataBuffer);
}
}
}
}
catch { //Ignore }
}
}
Watcher for txt file:
private void fileSystemWatcher2_Created(object sender, FileSystemEventArgs e)
{
//this is for txt file
Thread.Sleep(3500);
if (File.Exists(e.FullPath))
{
//make my actions
}
else
{
//make my actions
}
}
Actually FileSystemWatcher Created event called in separate thread by .NET itself.. So basically you need to do absolutely nothing. Your code is OK as it is.
Here is the proof:
class Program
{
static void Main(string[] args)
{
FileSystemWatcher fw = new FileSystemWatcher(@"C:\temp");
fw.Created += fileSystemWatcher_Created;
Console.WriteLine(Thread.CurrentThread.ManagedThreadId);
fw.EnableRaisingEvents = true;
Console.ReadLine();
}
static void fileSystemWatcher_Created(object sender, FileSystemEventArgs e)
{
Console.WriteLine(Thread.CurrentThread.ManagedThreadId);
}
}