WinForm : 로그인

Form 1

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 static System.Windows.Forms.VisualStyles.VisualStyleElement;

namespace WinForm_SignIn {
    public partial class Form1 : Form {

        Connect_DB cDB = new Connect_DB();

        private string id;
        private string name;
        private string password;
        private string password2;
        private string birth_year;
        private string birth_mon;
        private string birth_day;
        private string email;
        private string addr;
        private string phone;
        private string gender;
        private string intorduce;

        public Form1() {
            InitializeComponent();
            
        }

        private void idTextBox_TextChanged(object sender, EventArgs e) {
            
        }

        private void idTextBox_KeyPress(object sender, KeyPressEventArgs e) {
            if (e.KeyChar == (char)Keys.Enter) {

                char[] arr = idTextBox.Text.ToCharArray();

                int n = (int)(char.GetNumericValue(arr[0]));

                if (arr.Length < 4 || arr.Length > 8) {
                    MessageBox.Show("아이디 길이는 5글자 이상 8글자 이내");
                    idTextBox.Clear();
                    idTextBox.Focus();
                }
                else if (n != -1) {
                    MessageBox.Show("아이디를 다시 입력하세요\n첫글자는 숫자를 사용할수 없습니다.");
                    idTextBox.Clear();
                    idTextBox.Focus();
                }
                else {
                    this.id = idTextBox.Text;
                    passTextBox.Focus();
                }
            }
        }

        private void passTextBox_TextChanged(object sender, EventArgs e) {

            this.password = passTextBox.Text;
            this.password2 = passTextBoxConf.Text;
        }

        private void nameTextBox_TextChanged(object sender, EventArgs e) {
            this.name = nameTextBox.Text;
        }

        private void yearBox_TextChanged(object sender, EventArgs e) {
            this.birth_year = yearBox.Text + "년 ";
        }
        private void monBox_TextChanged(object sender, EventArgs e) {
            this.birth_mon = monBox.Text + "월 ";
        }
        private void dayBox_TextChanged(object sender, EventArgs e) {
            this.birth_day = dayBox.Text + "일";
        }

        private void callBox1_TextChanged(object sender, EventArgs e) {
            this.phone = callBox1.Text;
        }

        private void mailIdBOX_TextChanged(object sender, EventArgs e) {
            this.email = mailIdBOX.Text + "@" + mailBox2.Text;
        }

        private void addrBox_TextChanged(object sender, EventArgs e) {
            this.addr = addrBox.Text;
        }

        private void radioButton1_CheckedChanged(object sender, EventArgs e) {
            radio_Selected(radioButton1);
        }

        private void radioButton2_CheckedChanged(object sender, EventArgs e) {
            radio_Selected(radioButton2);
        }

        private string radio_Selected(RadioButton r) {

            if (r.Checked) {
                this.gender = r.Text;

                return gender;
            }
            else {
                gender = null;
                return gender;
            }  
        }

        private void introBox_TextChanged(object sender, EventArgs e) {
            intorduce = introBox.Text;
        }

        private void conformB_Click(object sender, EventArgs e) {

            MessageBox.Show($"ID : {this.id}\n이름 : {this.name}\n" +
                $"생년월일 : {this.birth_year}{this.birth_mon}{this.birth_day}\n연락처 : {this.phone}\n" +
                $"주소 : {this.addr}\n성별 : {this.gender}\n소개 : {this.intorduce}\n패스워드 : {this.password} ");

            
            cDB.insertTable(this.id,this.password,this.name,this.gender,this.email,this.addr,this.phone,this.intorduce);
        }

        private void cancelB_Click(object sender, EventArgs e) {
            cDB.disconnectDB();
        }

    }
}