Filesystem watcher and large files

var fsw = new FileSystemWatcher(sPath, "*.PPF");
fsw.NotifyFilter = NotifyFilters.FileName;
fsw.IncludeSubdirectories = true;
fsw.Created += FswCreated;
fsw.EnableRaisingEvents = true;

static void FswCreated(object sender, FileSystemEventArgs e)
{
  string sFile = e.FullPath;
  string[] arrLines = File.ReadAllLines(sFile);
}

this fails with large files, because the process is not finnished with writing the file. The file is copied via the Network, so i dont know the size of the file. What kind of syncronisation is required to make this robust?