Monitoring a MySQL Server Process

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Diagnostics;
using System.Text;
using System.IO;
using System.Windows.Forms;

namespace MySQLserverMonitor
{
    public partial class Form1 : Form
    {
        string appPath = null;
        bool serverStat = false;
        
        public event EventHandler<serverEventArgs> RaiseServerEvent; //declare event
        public Form1()
        {
            InitializeComponent();
            RaiseServerEvent += new EventHandler<serverEventArgs>(Form1_RaiseServerEvent); //subscribe event
        }

        void Form1_RaiseServerEvent(object sender, Form1.serverEventArgs e)
        {
            if (e.ServerStatus)
            {
                lblServerStatus.Text = "server started";
                lblServerStatus.ForeColor = Color.Green;
                lblStatusContext.Text = "server started";
                lblStatusContext.ForeColor = Color.Green;
                btnStart.Enabled = false; //this prevent user from clicking thus create new process
                btnStop.Enabled = true;
                mnuStart.Enabled = false;
                mnuStop.Enabled = true;
                notifyIcon1.Text = "mySQL server is running";                
                notifyIcon1.Icon = MySQLserverMonitor.Properties.Resources.database_server_on;
            }
            else
            {
                lblServerStatus.Text = "server stopped";
                lblServerStatus.ForeColor = Color.Salmon;
                lblStatusContext.Text = "server stopped";
                lblStatusContext.ForeColor = Color.Salmon;
                btnStop.Enabled = false; //an error will occur when no process can stop
                btnStart.Enabled = true;
                mnuStop.Enabled = false;
                mnuStart.Enabled = true;
                notifyIcon1.Text = "mySQL server is not running";
                notifyIcon1.Icon = MySQLserverMonitor.Properties.Resources.database_server_off;
            }
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            Process[] server =  Process.GetProcessesByName("mysqld");            
            if (server.Length != 0)
            {
                bool stat = true;
                if (serverStat != stat) //check if current status same as previous. this prevent notification always shown
                {
                    OnRaiseServerEvent(new serverEventArgs(true)); //raise server event
                    serverStat = stat;
                }
                //assume just one process running
                //lblCPUcost.Text = (server[0].UserProcessorTime.Ticks / server[0].TotalProcessorTime.Ticks * 100).ToString (); //view cpu cost 
                lblHost.Text = server[0].MachineName;
                lblMemCost.Text = server[0].WorkingSet64.ToString() + " Bytes";
                lblNPmemsize.Text = server[0].NonpagedSystemMemorySize64.ToString() + " Bytes";
                lblPID.Text = server[0].Id.ToString();
                lblStartTime.Text = server[0].StartTime.ToString();
            }
            else
            {
                bool stat = false ;
                if (serverStat != stat) //check if current status same as previous. this prevent notification always shown
                {
                    OnRaiseServerEvent(new serverEventArgs(false)); //raise server event
                    serverStat = stat; //update global status
                }          
                
            }
        }

        private void btnStart_Click(object sender, EventArgs e)
        {
            FileInfo fi = new FileInfo(appPath + "\\mysqld.exe");
            if (fi.Exists)
                Process.Start(fi.FullName);
            else
                errorProvider1.SetError(txtPath, "this isn't mysql installation directory");
        }

        private void btnBrowse_Click(object sender, EventArgs e)
        {
            if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)
            {
                 txtPath.Text = folderBrowserDialog1.SelectedPath;                 
            }
            folderBrowserDialog1.Dispose();
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            DirectoryInfo di = new System.IO.DirectoryInfo(txtPath.Text);
            if (di.Exists)
            {
                StreamWriter confFile = new StreamWriter(System.Environment.CurrentDirectory + "\\conf.txt"); //write configuration to file
                confFile.WriteLine(di.FullName);
                confFile.Flush(); //write to stream
                confFile.Close(); //release stream and memory
                appPath = di.FullName;
                timer1.Enabled = true;
                lblServerStatus.ForeColor = Color.Black;
                btnStart.Enabled = true;
                btnStop.Enabled = true;
                errorProvider1.SetError(txtPath, "");
                timer1.Enabled = true;
                serverStat = false;
                btnStop.Enabled = false; //assume  server is stopped at application start
            }
            else
                errorProvider1.SetError(txtPath, "folder not exist");
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            FileInfo confFile = new FileInfo (System.Environment.CurrentDirectory + "\\conf.txt"); //check file
            if (confFile.Exists)
            {
                StreamReader confStream = new StreamReader(confFile.FullName); //read configuration file
                appPath = confStream.ReadLine(); //read conf data which is directory of mysql installation
                txtPath.Text = appPath;
                timer1.Enabled = true;
            }
            else
            {
                lblServerStatus.Text = "unknown mySQL installation directory";
                lblServerStatus.ForeColor = Color.Red; //show notification
                btnStart.Enabled = false; //don't let user click these button or it'll raise error
                btnStop.Enabled = false;
            }
            Process[] server = Process.GetProcessesByName("mysqld"); //check on start
            if (server.Length != 0)
            {
                OnRaiseServerEvent(new serverEventArgs(true));
                timer1.Enabled = true;
            }
            else
                OnRaiseServerEvent(new serverEventArgs(false));
        }

        private void txtPath_Validating(object sender, CancelEventArgs e)
        {
            DirectoryInfo di = new System.IO.DirectoryInfo(txtPath.Text);
            if (!(di.Exists))
                errorProvider1.SetError(txtPath, "folder not exist"); //show error message
            else
                errorProvider1.SetError(txtPath, ""); //clear error message
        }

        private void btnStop_Click(object sender, EventArgs e)
        {
            FileInfo fi = new FileInfo (appPath + "\\mysqladmin.exe");
            if (fi.Exists)
            {
                Process.Start(fi.FullName, "--user=root shutdown");
            }
            else
                errorProvider1.SetError(txtPath, "this isn't mysql installation directory");
        }

        private void restoreToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.Show(); //show hidden form
        }
        /// <summary>
        /// argument on server status change
        /// </summary>
        public class serverEventArgs : EventArgs 
        {
            private bool serverStatus;
            public serverEventArgs(bool statusServer)
            {
                serverStatus = statusServer;
            }
            public bool ServerStatus
            {
                get { return serverStatus; }
                set { serverStatus = value; }
            }
        }
        
        protected virtual void OnRaiseServerEvent(serverEventArgs e)
        {
            EventHandler<serverEventArgs> handler = RaiseServerEvent; 
            //read help : how to publish Publish Events that Conform to .NET Framework Guidelines (C# Programming Guide)
            if (handler != null)
            {
                handler(this, e);
            }
        }

        private void chkOnTop_CheckedChanged(object sender, EventArgs e)
        {            
                this.TopMost = chkOnTop.Checked;
        }

        private void btnhide_Click(object sender, EventArgs e)
        {
            this.Hide(); //hide form
        }

        private void mnuExit_Click(object sender, EventArgs e)
        {
            notifyIcon1.Dispose(); 
            this.Close(); //close the form
        }
    }
}