How do i get the Update operation working in this C# CRUD ?

Question

In this C#  CRUD. Only the Update function is not working at all while the Add, Clear and Delete are working as planed.   

 

What do i need to edit to the code to get the Update class to work as planed? 

 

Source code see the .zipfile or see below. 

using AContact.AContactClasses;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

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

        ContactClass c = new ContactClass();

        private void BtnAdd_Click(object sender, EventArgs e)
        {

            // Get the value from the input fields
            c.FirstName = tbFirstName.Text;
            c.LastName = tbLastName.Text;
            c.Phone = tbPhone.Text;
            c.Email = tbEmail.Text;
            c.Note = tbNote.Text;
            c.Status = cmbStatus.Text;

            // Inserting datat into database
            bool success = c.Insert(c);
            if (success == true)
            {
                // succesfully Inserted
                MessageBox.Show("New contact succesfully inserted");
                // Call the Clear method here
                Clear();
            }
            else
            {
                // Faild to add contact
                MessageBox.Show("Failed to add new contact. Try again.");
            }

        // load data on Gridview
        DataTable dt = c.Select();
        dgvContactList.DataSource = dt;

        }

        private void AContact_Load(object sender, EventArgs e)
        {
            // load data on Gridview
            DataTable dt = c.Select();
            dgvContactList.DataSource = dt;
        }

        // Method to clear fields
        public void Clear()
        {
            tbFirstName.Text = "";
            tbLastName.Text = "";
            tbPhone.Text = "";
            tbEmail.Text = "";
            tbNote.Text = "";
            cmbStatus.Text = "";
        }


        private void BtnUpdate_Click(object sender, EventArgs e)
        {
            // Get the data from textboxes
            c.ContactID = int.Parse(tbContactID.Text);
            c.FirstName = tbFirstName.Text;
            c.LastName = tbLastName.Text;
            c.Phone = tbPhone.Text;
            c.Email = tbEmail.Text;
            c.Note = tbNote.Text;
            c.Status = cmbStatus.Text;
            // Update data in database
            bool success = c.Update(c);
            if (success==true)
            {
                // Updated succesfully
                MessageBox.Show("Contact has been succesfully Updated");
                // Load data on Data Gridview
                DataTable dt = c.Select();
                dgvContactList.DataSource = dt;
                // Call Clear Method
                Clear();
            }
            else
            {
                // Failed to Update
                MessageBox.Show("Failed to update. Try again.");
            }
        }

        private void BtnDelete_Click(object sender, EventArgs e)
        {
            c.ContactID = Convert.ToInt32(tbContactID.Text);
            bool success = c.Delete(c);
            if (success == true)
            {
                // Succesfully deleted
                MessageBox.Show("Contact succesfully deleted.");
                // Refresh data GridView
                // Load Data on Data GridView
                DataTable dt = c.Select();
                dgvContactList.DataSource = dt;
                // Call the  Clear methode here
                Clear();
            }
            else
            {
                // Failed to delete
                MessageBox.Show("Failed to delete contact. Try again.");
            }

        }

        private void BtnClear_Click(object sender, EventArgs e)
        {
            // Call Clear method here
            Clear();
        }

        private void dgvContactList_RowHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
        {
            // Get data from Data Grid View and load it to the textboxes respectively
            // Identify the row on witch mouse is clicked
            int rowIndex = e.RowIndex;
            tbContactID.Text = dgvContactList.Rows[rowIndex].Cells[0].Value.ToString();
            tbFirstName.Text = dgvContactList.Rows[rowIndex].Cells[1].Value.ToString();
            tbLastName.Text = dgvContactList.Rows[rowIndex].Cells[2].Value.ToString();
            tbPhone.Text = dgvContactList.Rows[rowIndex].Cells[3].Value.ToString();
            tbEmail.Text = dgvContactList.Rows[rowIndex].Cells[4].Value.ToString();
            tbNote.Text = dgvContactList.Rows[rowIndex].Cells[5].Value.ToString();
            cmbStatus.Text = dgvContactList.Rows[rowIndex].Cells[6].Value.ToString();
        }
    }
    }

ContactClass.cs

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AContact.AContactClasses
{
    class ContactClass
    {
        // Getter and Setters properties
        // Acts as a data carrier in this application
        public int ContactID { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Phone { get; set; }
        public string Email { get; set; }
        public string Note { get; set; }   public string Status { get; set; }

        static string myconnstrng = ConfigurationManager.ConnectionStrings["connstrng"].ConnectionString;

        // Selecting data from database
        public DataTable Select()
        {
            // step 1: Database connection
            SqlConnection conn = new SqlConnection(myconnstrng);
            DataTable dt = new DataTable();
            try
            {
                // step 2: Writing sql query
                string sql = "SELECT * FROM tbl_contact";
                // Creating cmd using sql and conn
                SqlCommand cmd = new SqlCommand(sql, conn);
                // Creating sql DataAdappter using cmd
                SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                conn.Open();
                adapter.Fill(dt);
            }
            catch (Exception ex)
            {

            }
            finally
            {
                conn.Close();
            }
            return dt;
        }
        // Inserting into database
        public bool Insert(ContactClass c)
        {
            // Creating a default returntype and setting its value to false
            bool isSuccess = false;

            // Step 1. Connect database
            SqlConnection conn = new SqlConnection(myconnstrng);
            try
            {
                // Step 2: Create a SQL query to insert data
          string sql = "INSERT INTO tbl_contact (FirstName, LastName, Phone, Email, Note, Status) VALUES(@FirstName, @LastName, @Phone, @Email, @Note, @Status)";
                // Creating SQL Command using sql and conn
                SqlCommand cmd = new SqlCommand(sql, conn);
                // Create Parameters to add data
                cmd.Parameters.AddWithValue("@FirstName", c.FirstName);
                cmd.Parameters.AddWithValue("@LastName", c.LastName);
                cmd.Parameters.AddWithValue("@Phone", c.Phone);
                cmd.Parameters.AddWithValue("@Email", c.Email);
                cmd.Parameters.AddWithValue("@Note", c.Note);
                cmd.Parameters.AddWithValue("@Status", c.Status);

                // Connection Open here
                conn.Open();
                int rows = cmd.ExecuteNonQuery();
                // If the query runs succesfully then the value is > 0, else the value will be < 0
                if (rows > 0)
                {
                    isSuccess = true;
                }
                else
                {
                    isSuccess = false;
                }

            }
            catch (Exception ex)
            {

            }
            finally
            {
                conn.Close();
            }
            return isSuccess;
        }

        // Method to update data in database
        public bool Update(ContactClass c)
        {
            // Create a default return type and set its default value to false
            bool isSuccess = false;
            SqlConnection conn = new SqlConnection(myconnstrng);
            try
            {
                // SQL to update data in hour database
string sql = "UPDATE tbl_contact SET FirstName=@FirstName, LastName=@LastName, Phone=@Phone, Email=@Email, Note=@Note, Status=@Status WHERE ContactID=@ContactID";

                // Creating SQL command
                SqlCommand cmd = new SqlCommand(sql, conn);
                // Create Parameters to add value
                cmd.Parameters.AddWithValue("@FirstName",   c.FirstName);
                cmd.Parameters.AddWithValue("@FirstName",   c.LastName);
                cmd.Parameters.AddWithValue("@Phone",       c.Phone);
                cmd.Parameters.AddWithValue("@Email",       c.Email);
                cmd.Parameters.AddWithValue("@Note",        c.Note);
                cmd.Parameters.AddWithValue("@Status",      c.Status);
                cmd.Parameters.AddWithValue("@ContactID",   c.ContactID);

                // Open database connection
                conn.Open();

                int rows = cmd.ExecuteNonQuery();
                // If the query runs succesfully then the value of rows > 0 else its value will be 0
                if (rows > 0)
                {
                    isSuccess = true;
                }
                else
                {
                    isSuccess = false;
                }
            }
            catch (Exception ex)
            {
            }
            finally
            {
                conn.Close();
            }
            return isSuccess;
        }
        // Method to delete data from database
        public bool Delete(ContactClass c)
        {
            // create a default return value and set its value to false
            bool isSuccess = false;
            // Create SQL Connection
            SqlConnection conn = new SqlConnection(myconnstrng);
            try
            {
                //  Method to delete data
                string sql = "DELETE FROM tbl_contact WHERE ContactID=@ContactID";
                // Creating SQL command
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.Parameters.AddWithValue("@ContactID", c.ContactID);
                // Open Connection
                conn.Open();
                int rows = cmd.ExecuteNonQuery();
                // if the query runs succesfully then the value of rows will be > 0 , else the value will be 0
                if (rows > 0)
                {
                    isSuccess = true;
                }
                else
                {
                    isSuccess = false;
                }
            }
            catch (Exception ex)
            {
            }
            finally
            {
                // Close connection
                conn.Close();
            }
            return isSuccess;
        }
    }
}