winform+SQL 的超市管理

超市管理系统，模拟其他实例制作，界面有点雷同，但是代码不一样。只要用于初学者掌握winform 的控件的应用，SQL的数据库操作using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Data.SqlClient;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;using System.Windows.Forms.VisualStyles;using Wingtech.SuperMarket.BaseFunction;namespace Wingtech.SuperMarket{ public partial class Login : Form { public Login() { InitializeComponent(); btnCancel.Click = BtnCancel_Click; btnOK.Click = BtnOK_Click; this.Load = Login_Load; } private void Login_Load(object sender, EventArgs e) { } private void BtnOK_Click(object sender, EventArgs e) { if (txtUserName.Text!="" && txtPwd.Text!="") { string sql ="select count(*) from tb_EmpInfo where EmpLoginName=@EmpLoginName and EmpLoginPwd=@EmpLoginPwd"; if ((int)(SqlHelper.ExecuteScalar(SqlHelper.connectionString,CommandType.Text,sql, new SqlParameter[] { new SqlParameter("@EmpLoginName",txtUserName.Text.Trim()), new SqlParameter("@EmpLoginPwd",txtPwd.Text.Trim()) }))==1) { this.Hide(); Main main = new Main(); main.toolStripStatusUser.Text = txtUserName.Text; main.EmpLoginName = txtUserName.Text.Trim(); main.Show(); } else { MessageBox.Show("UserName or Pwd Error!"); return; } } else { MessageBox.Show("UserName or Pwd is Empoty!"); return; } } private void BtnCancel_Click(object sender, EventArgs e) { this.Close(); } }}