C# DGV ส่งค่าไปแก้ไข้ RadioButton ยังไง/ บันทึกแล้ว ให้ DGV เคลียร์

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;
using System.Data.SqlClient;

namespace WindowsFormsApplication1
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        string gender;
        string status;
               
        private void button3_Click(object sender, EventArgs e)
        {   
                using (SqlConnection conn = new SqlConnection())
                {

                    {
                        Config config = new Config();
                        string constring = config.ConnString;
                        conn.ConnectionString = constring;
                        conn.Open();
 
                        string sql = "SELECT * FROM tbNCD WHERE HN_N ='"+textBox3.Text+"' ";
                        SqlCommand com = new SqlCommand(sql, conn);
                        DataTable dt = new DataTable();
                        SqlDataAdapter da = new SqlDataAdapter(sql, conn);
                        da.Fill(dt);
                        dataGridView1.Rows.Clear();
                        foreach (DataRow row in dt.Rows)
                        {
                            int n = dataGridView1.Rows.Add();
                            dataGridView1.Rows[n].Cells[0].Value = row["HN_N"].ToString();
                            dataGridView1.Rows[n].Cells[1].Value = row["Name_N"].ToString();
                            dataGridView1.Rows[n].Cells[2].Value = row["Gender_N"].ToString();
                            dataGridView1.Rows[n].Cells[3].Value = row["Bag_N"].ToString();

                        }                        
                        textBox3.Clear();     
                        textBox3.Focus();
                    }
                }
        }

        private void radioButton1_CheckedChanged(object sender, EventArgs e)
        {
            gender = "ชาย";
        }

        private void radioButton2_CheckedChanged(object sender, EventArgs e)
        {
            gender = "หญิง";
        }

        private void radioButton3_CheckedChanged(object sender, EventArgs e)
        {
            status = "ไม่มี";
        }

        private void radioButton4_CheckedChanged(object sender, EventArgs e)
        {
            status = "มี";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.Hide();
            Form1 frm1 = new Form1();
            frm1.Show();
        }

        private void Form2_Load(object sender, EventArgs e)
        {    
            textBox3.Select();
        }

        private void dataGridView1_CellMouseClick(object sender, DataGridViewCellMouseEventArgs e)
        {
            if (e.RowIndex == -1) return;
            textBox1.Text = dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString();
            textBox2.Text = dataGridView1.Rows[e.RowIndex].Cells[1].Value.ToString();
            gender = dataGridView1.Rows[e.RowIndex].Cells[2].Value.ToString();
            status = dataGridView1.Rows[e.RowIndex].Cells[3].Value.ToString();

           
        }

        private void button4_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if ((textBox1.Text == "") || (textBox2.Text == "") || (radioButton1.Checked == false) && (radioButton2.Checked == false) ||
                (radioButton3.Checked == false) && (radioButton4.Checked == false))
            {
                MessageBox.Show("กรุณากรอกข้อมูลให้ครบ", "คำเตือน", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
            else
            {
                using (SqlConnection conn = new SqlConnection())
                {
                    Config config = new Config();
                    string constring = config.ConnString;
                    conn.ConnectionString = constring;
                    conn.Open();

                    string sql = "UPDATE tbNCD SET HN_N = '" + textBox1.Text + "' ,Name_N = '" + textBox2.Text + "' ,Gender_N = '" +
                        gender + "' ,Bag_N = '" + status + "' WHERE HN_N ='" + textBox1.Text + "' ";
                    SqlCommand com = new SqlCommand(sql, conn);
                    com.ExecuteNonQuery();
                    conn.Close();
                    MessageBox.Show("แก้ไขสำเร็จ");

                    textBox1.Clear();
                    textBox2.Clear();
                    radioButton1.Checked = false;
                    radioButton2.Checked = false;
                    radioButton3.Checked = false;
                    radioButton4.Checked = false;
                    
                    textBox1.Focus();
                    conn.Close();
                }
            }
        }

        private void dataGridView1_DoubleClick(object sender, EventArgs e)
        {

        }
    }
}