Monitor Multiple Files using FileSystemWatcher

• Download source code - 13.3 KB

Introduction

This code will show how to monitor multiple files by creating multiple instances of FileSystemWatcher.

Using the code

To use the code, the following namespaces must be referenced:

using System.IO; 
using System.Collections;

System.IO will be used for FileSystemWatcher and Directory, while System.Collections for the ArrayList. Now to the code:

namespace MonitorFolderActivity
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnRun_Click(object sender, EventArgs e)
        {
            DisableButtons();
            bool bMonitorUpdated = chkMonitorUpdated.Checked;
            bool bMonitorDeleted = chkMonitorDeleted.Checked; 
            bool bMonitorCreated = chkMonitorCreated.Checked;

            ArrayList aFileWatcherInstance = new ArrayList();

            foreach (string sMonitorFolder in lstFolders.Items)
            {
                //Check if Directory Exisits
                if (Directory.Exists(sMonitorFolder))
                {
                    FileSystemWatcher oFileWatcher = new FileSystemWatcher();

                    //Set the path that you want to monitor.
                    oFileWatcher.Path = sMonitorFolder;

                    //Set the Filter Expression.
                    oFileWatcher.Filter = txtMonitorFileExpression.Text;

                    if (bMonitorUpdated)
                        oFileWatcher.Changed += 
                          new System.IO.FileSystemEventHandler(FileSystemWatcherUpdated);
                    else
                        oFileWatcher.Changed -= 
                          new System.IO.FileSystemEventHandler(FileSystemWatcherUpdated);

                    if (bMonitorDeleted)
                        oFileWatcher.Deleted += 
                          new System.IO.FileSystemEventHandler(FileSystemWatcherDeleted);
                    else
                        oFileWatcher.Deleted -= 
                          new System.IO.FileSystemEventHandler(FileSystemWatcherDeleted);

                    if (bMonitorCreated)
                        oFileWatcher.Created += 
                          new System.IO.FileSystemEventHandler(FileSystemWatcherCreated);
                    else
                        oFileWatcher.Created -= 
                          new System.IO.FileSystemEventHandler(FileSystemWatcherCreated);

                    oFileWatcher.EnableRaisingEvents = true;

                    //Add a new instance of FileWatcher 
                    aFileWatcherInstance.Add(oFileWatcher);
                }
            }
        }
        void FileSystemWatcherCreated(object sender, System.IO.FileSystemEventArgs e)
        {
            //A file has been deleted from the monitor directory.
            string sLog = "File Created: " + e.Name;
            AppendText(sLog);
        }
        void FileSystemWatcherDeleted(object sender, System.IO.FileSystemEventArgs e)
        {
            //A file has been deleted from the monitor directory.
            string sLog = "File Deleted: " + e.Name;
            AppendText(sLog);
        }
        void FileSystemWatcherUpdated(object sender, System.IO.FileSystemEventArgs e)
        {
            //A file has been deleted from the monitor directory.
            string sLog = "File Updated: " + e.Name;
            AppendText(sLog);
        }

        private delegate void AppendListHandler(string sLog);
        private void AppendText(string sLog)
        {
            if (lstResultLog.InvokeRequired)
                lstResultLog.Invoke(new AppendListHandler(AppendText), 
                                    new object[] { sLog });
            else
                lstResultLog.Items.Add(Convert.ToString(DateTime.Now) + 
                                       " - " + sLog);
        }

        private void DisableButtons()
        {
            chkMonitorUpdated.Enabled = false;
            chkMonitorDeleted.Enabled = false;
            chkMonitorCreated.Enabled = false;
            txtMonitorFileExpression.Enabled = false;
            btnRun.Enabled = false;

        }
    }
}