本文实例为大家分享了C#实现餐厅管理系统的具体代码，供大家参考，具体内容如下

部分代码：

fm_change_password.cs

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.IO;using System.Data.SqlClient;namespace FoodManage{ public partial class fm_change_password : Form { public fm_change_password() { InitializeComponent(); } public string useridname = ""; private void bt_ok_Click(object sender, EventArgs e) { SqlConnection conn=new SqlConnection(fm_public.strcon); conn.Open(); SqlDataAdapter sda = new SqlDataAdapter("SELECT Password FROM TUser WHERE UserIDName='" + useridname + "'", conn); DataTable DT=new DataTable(); sda.Fill(DT); if(DT.Rows[0]["Password"].ToString()!=tb_oldpass.Text) { MessageBox.Show("旧密码错误请重新输入"); return; } if (tb_newpassw.Text != tb_newpass.Text) { MessageBox.Show("两次密码不相同请重新输入"); return; } SqlCommand cmd = new SqlCommand("UPDATE TUser SET Password=@Password WHERE UserIDName='" + useridname + "'", conn); cmd.Parameters.Add("@Password",SqlDbType.VarChar,128).Value=tb_newpassw.Text; cmd.ExecuteNonQuery(); MessageBox.Show("修改密码成功！(*￣︶￣)y "); conn.Close(); this.Close(); } private void bt_esc_Click(object sender, EventArgs e) { this.Close(); } }}

fm_login.cs

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Data.SqlClient;namespace FoodManage{ public partial class fm_login : Form { public fm_login() { InitializeComponent(); } private void bt_login_Click(object sender, EventArgs e) { //判断用户名或密码文本框是否为空 if(tb_username.Text==""||tb_password.Text=="") { if(tb_username.Text=="") { MessageBox.Show("用户名为空，请重新输入！(*￣︶￣)y "); return; } if (tb_password.Text == "") { MessageBox.Show("密码为空，请重新输入！(*￣︶￣)y "); return; } } //连接数据库 SqlConnection conn = new SqlConnection(fm_public.strcon); conn.Open(); string selectsql = "SELECT * FROM TUser WHERE UserIDName='" + tb_username.Text + "'"; SqlDataAdapter sda = new SqlDataAdapter(selectsql, conn); DataTable dt = new DataTable(); sda.Fill(dt); //判断用户是否存在 if (dt.Rows.Count == 0) { MessageBox.Show("无该用户"); return; } //判断用户名是否被锁定 if (Convert.ToBoolean(dt.Rows[0]["LockIf"]) == true) { MessageBox.Show("该用户已经被锁定，请联系管理员！/(ㄒoㄒ)/~~ "); return; } //更新数据库前的准备 SqlCommand cmd = new SqlCommand(); cmd.Connection = conn; cmd.CommandType = CommandType.Text; //判断输入密码是否正确，输入错误则“错误次数”+1，成功登录则“错误次数”清零 if(tb_password.Text!=dt.Rows[0]["Password"].ToString()) { //错误次数+1 cmd.CommandText = @"UPDATE TUser SET ErrorTime=ErrorTime+1 WHERE UserIDName=@UserName"; cmd.Parameters.Add("@UserName", SqlDbType.VarChar, 8); cmd.Parameters["@UserName"].Value = tb_username.Text.Trim(); cmd.ExecuteNonQuery(); MessageBox.Show("密码错误请重新输入！/(ㄒoㄒ)/~~ "); return; } //经过以上验证用户名密码无错执行以下代码（设置错误次数为0） cmd.CommandText = "update TUser set ErrorTime=0 where UserIDName=@UserName"; cmd.Parameters.Add("@UserName", SqlDbType.VarChar, 8); cmd.Parameters["@UserName"].Value = tb_username.Text.Trim(); cmd.ExecuteNonQuery(); conn.Close(); fm_public.LoginSuccess = true; //设置用户权限以及初始化主界面的相关参数 if (dt.Rows[0]["Post"].ToString() == "管理员") { fm_public.userpower = "管理员"; } else { fm_public.userpower = "服务员"; } fm_public.useridname = dt.Rows[0]["UserIDName"].ToString(); fm_public.logintime = DateTime.Now.ToShortDateString(); this.Close(); } private void bt_esc_Click(object sender, EventArgs e) { if (MessageBox.Show("确定退出系统吗？", "提示", MessageBoxButtons.OKCancel, MessageBoxIcon.Asterisk) == DialogResult.OK) { Application.Exit(); } } private void fm_login_Activated(object sender, EventArgs e) { tb_username.Focus(); } private void fm_login_Load(object sender, EventArgs e) { fm_start fm_starts = new fm_start(); fm_starts.ShowDialog(); } }}

源码下载：C#实现餐厅管理系统

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