Tic Tac Toe (Game)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace final_tic
{
    public partial class Form1: Form
    {
        bool turn = true;
        int turn_count = 0;
        public Form1()
        {
            InitializeComponent();
        }
        private void button_Click(object sender, EventArgs e)
        {
            Button b = (Button) sender;
            if (turn) b.Text = "X";
            else b.Text = "O";
            b.Enabled = false;
            turn = !turn;
            turn_count++;
            check_winner();
        }
        private void check_winner()
        {
            bool winner = false;
            //horizental check
            if ((A1.Text == A2.Text) && (A2.Text == A3.Text) && (!A1.Enabled)) winner = true;
            else if ((B1.Text == B2.Text) && (B2.Text == B3.Text) && (!B1.Enabled)) winner = true;
            else if ((C1.Text == C2.Text) && (C2.Text == C3.Text) && (!C1.Enabled)) winner = true;
            //Vertical check
            else if ((A1.Text == B1.Text) && (B1.Text == C1.Text) && (!A1.Enabled)) winner = true;
            else if ((A2.Text == B2.Text) && (B2.Text == C2.Text) && (!A2.Enabled)) winner = true;
            else if ((A3.Text == B3.Text) && (B3.Text == C3.Text) && (!A3.Enabled)) winner = true;
            //Digonal check
            else if ((A1.Text == B2.Text) && (B2.Text == C3.Text) && (!A1.Enabled)) winner = true;
            else if ((A3.Text == B2.Text) && (B2.Text == C1.Text) && (!C1.Enabled)) winner = true;
            ///////////////////////////////////////////////////////////////////////
            if (winner)
            {
                disablebutton();
                string w = "";
                if (turn) w = "O";
                else w = "X";
                MessageBox.Show(w + " is winner", "Tic Tac Toe Result");
            }
            else if (turn_count == 9)
            {
                MessageBox.Show("Match is Draw", "Result");
            }
        }
        private void disablebutton()
        {
            try
            {
                foreach(Control c in Controls)
                {
                    Button b = (Button) c;
                    b.Enabled = false;
                }
            } catch {}
        }
        private void newGameToolStripMenuItem_Click(object sender, EventArgs e)
        {
            turn = true;
            turn_count = 0;
            try
            {
                foreach(Control c in Controls)
                {
                    Button b = (Button) c;
                    b.Enabled = true;
                    b.Text = "";
                }
            }
            catch {}
        }
        private void exitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
        private void aboutToolStripMenuItem_Click(object sender, EventArgs e)
        {
            MessageBox.Show("In tic Tac Toe ,when a sign match horizently,vertically or digonals,it wins.", "About");
        }
    }
}