C#_会员管理系统：开发五（用户注册）

创建一个新的用户注册窗体(VIPRegistration.cs):

用户注册窗体(VIPRegistration.cs)详细代码如下：

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;
using System.Configuration;

namespace 会员管理系统
{
    public partial class VIPRegistration : Form
    {
        public VIPRegistration()
        {
            InitializeComponent();
        }


        //提交按钮
        private void btnOK_Click(object sender, EventArgs e)
        {
            
            string connstr = ConfigurationManager.ConnectionStrings["str"].ConnectionString;
            SqlConnection conn = new SqlConnection(connstr);
            string sql = string.Format("select vusername from VipAccount where vUserName='{0}' ",txtName.Text);
            SqlCommand cmd = new SqlCommand(sql, conn);
            conn.Open();
            SqlDataReader sda=cmd.ExecuteReader();

            if (txtName.Text.Trim() == "")
            {
                lblName.Text="用户名不能为空";
                return;
            }
            else if (txtPwd.Text.Trim() == ""|| txtPwdConfirm.Text.Trim()=="")
            {
                lblPwd.Text = "密码不能为空";
                return;
            }
            else if (txtPwdConfirm.Text.Trim()!= txtPwd.Text.Trim())
            {
                lblPwdConfirm.Text = "两次密码输入不同，请确认后再输";
                return;
            }
            else if (sda.Read())
            {
                lblName.Text = "用户名已存在，请重新输入";
                return;
            }
            else
            {
                conn.Close();
                SqlConnection conninsert = new SqlConnection(connstr);
                string insertsql = string.Format("insert into VipAccount(vUserName,vUserPwd) values('{0}','{1}')",txtName.Text,txtPwd.Text);
                SqlCommand cmdinsert = new SqlCommand(insertsql, conninsert);
                conninsert.Open();
                int n = cmdinsert.ExecuteNonQuery();
                if (n == 0)
                {
                    MessageBox.Show("注册失败，请重新输入");
                }
                else
                {
                    MessageBox.Show("注册成功");
                }
                conninsert.Close();

            }
            //conn.Close();
        }

        //返回主菜单
        private void btnBack_Click(object sender, EventArgs e)
        {
            VIPMain vm = new VIPMain();
            vm.Show();
            this.Hide();
        }

        private void VIPRegistration_Load(object sender, EventArgs e)
        {
            lblName.Text = "";
            lblPwd.Text = "";
            lblPwdConfirm.Text = "";
        }
        
    }
}

主界面窗体(VIPMain.cs)添加一个新的按钮：

用户注册按钮代码：

        private void btnRegistration_Click(object sender, EventArgs e)
        {
            VIPRegistration vrn = new VIPRegistration();
            vrn.Show();
            this.Hide();
        }