登录页面后台验证
using System;using System.Collections.Generic;using ponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace MES_SimpleDemo{public partial class Login : Form{public Login(){InitializeComponent();}/**登录验证*/private void button1_Click(object sender, EventArgs e){//获取文本框中的值string username = this.textBox1.Text;string password = this.textBox2.Text;if(username.Equals("") || password.Equals(""))//用户名或密码为空{MessageBox.Show("用户名或密码不能为空");}else//用户名或密码不为空{//到数据库中验证string selectSql = "select * from tb_user where username='"+username+"' and password='"+password+"'";SqlHelp sqlHelper = new SqlHelp();int count = sqlHelper.SqlServerRecordCount(selectSql);//返回符合的结果数量if (count > 0)//如果信息>0则说明匹配成功{MessageBox.Show("信息验证成功");//将当前登录日志信息写入数据库(待开发...)//跳转到主页面Main view = new Main();//创建一个新页面view.Show();//显示新页面this.Hide();//隐藏当前页面}else{MessageBox.Show("用户名或密码错误");}}}/**输入框重置*/private void button2_Click(object sender, EventArgs e){this.textBox1.Text = "";this.textBox2.Text = "";}}}
数据库连接核心代码
using System;using System.Data;using System.Configuration;using System.Text.RegularExpressions;using System.Data.SqlClient;using System.IO;using .Mail;using System.Text;/// <summary>///主要包括sqlHelp数据库访问助手类 和常用的一些函数定义///</summary>///SqlHelp数据库访问助手///1.public static void OpenConn() //打开数据库连接///2.public static void CloseConn() //关闭数据库连接///3.public static SqlDataReader getDataReaderValue(string sql)//读取数据///4.public DataSet GetDataSetValue(string sql, string tableName) //返回DataSet///5.public DataView GetDataViewValue(string sql) //返回DataView///6.public DataTable GetDataTableValue(string sql) //返回DataTable///7.public void ExecuteNonQuery(string sql) //执行一个SQL操作:添加、删除、更新操作///8.public int ExecuteNonQueryCount(string sql)//执行一个SQL操作:添加、删除、更新操作，返回受影响的行///9.public static object ExecuteScalar(string sql) //执行一条返回第一条记录第一列的SqlCommand命令///10.public int SqlServerRecordCount(string sql) //返回记录数///常用函数///1.public static bool IsNumber(string a)//判断是否为数字///2.public static string GetSafeValue(string value)//过滤非法字符namespace MES_SimpleDemo{class SqlHelp{///私有属性:数据库连接字符串///Data Source=(Local)服务器地址///Initial Catalog=SimpleMESDB 数据库名称///User ID=sa 数据库用户名///Password=admin123456 数据库密码private const string connectionString = "Data Source=(Local);Pooling=False;Max Pool Size = 1024;Initial Catalog=SimpleMESDB;Persist Security Info=True;User ID=sa;Password=admin123456";/// <summary>/// sqlHelp 的摘要说明:数据库访问助手类/// sqlHelper是从DAAB中提出的一个类，在这里进行了简化，DAAB是微软Enterprise Library的一部分，该库包含了大量大型应用程序/// 开发需要使用的库类。/// </summary>public void SqlHelp(){//无参构造函数}public static SqlConnection conn;//打开数据库连接public static void OpenConn(){string SqlCon = connectionString;//数据库连接字符串conn = new SqlConnection(SqlCon);if (conn.State.ToString().ToLower() == "open"){}else{conn.Open();}}//关闭数据库连接public static void CloseConn(){if (conn.State.ToString().ToLower() == "open"){//连接打开时conn.Close();conn.Dispose();}}// 读取数据public static SqlDataReader GetDataReaderValue(string sql){OpenConn();SqlCommand cmd = new SqlCommand(sql, conn);SqlDataReader dr = cmd.ExecuteReader();CloseConn();return dr;}// 返回DataSetpublic DataSet GetDataSetValue(string sql, string tableName){OpenConn();SqlDataAdapter da;DataSet ds = new DataSet();da = new SqlDataAdapter(sql, conn);da.Fill(ds, tableName);CloseConn();return ds;}// 返回DataViewpublic DataView GetDataViewValue(string sql){OpenConn();SqlDataAdapter da;DataSet ds = new DataSet();da = new SqlDataAdapter(sql, conn);da.Fill(ds, "temp");CloseConn();return ds.Tables[0].DefaultView;}// 返回DataTablepublic DataTable GetDataTableValue(string sql){OpenConn();DataTable dt = new DataTable();SqlDataAdapter da = new SqlDataAdapter(sql, conn);da.Fill(dt);CloseConn();return dt;}// 执行一个SQL操作:添加、删除、更新操作public void ExecuteNonQuery(string sql){OpenConn();SqlCommand cmd;cmd = new SqlCommand(sql, conn);cmd.ExecuteNonQuery();cmd.Dispose();CloseConn();}// 执行一个SQL操作:添加、删除、更新操作，返回受影响的行public int ExecuteNonQueryCount(string sql){OpenConn();SqlCommand cmd;cmd = new SqlCommand(sql, conn);int value = cmd.ExecuteNonQuery();return value;}//执行一条返回第一条记录第一列的SqlCommand命令public object ExecuteScalar(string sql){OpenConn();SqlCommand cmd;cmd = new SqlCommand(sql, conn);object value = cmd.ExecuteScalar();return value;}// 返回记录数public int SqlServerRecordCount(string sql){OpenConn();SqlCommand cmd = new SqlCommand();mandText = sql;cmd.Connection = conn;SqlDataReader dr;dr = cmd.ExecuteReader();int RecordCount = 0;while (dr.Read()){RecordCount = RecordCount + 1;}CloseConn();return RecordCount;}///<summary>///一些常用的函数///</summary>//判断是否为数字public static bool IsNumber(string a){if (string.IsNullOrEmpty(a))return false;foreach (char c in a){if (!char.IsDigit(c))return false;}return true;}// 过滤非法字符public static string GetSafeValue(string value){if (string.IsNullOrEmpty(value))return string.Empty;value = Regex.Replace(value, @";", string.Empty);value = Regex.Replace(value, @"'", string.Empty);value = Regex.Replace(value, @"&", string.Empty);value = Regex.Replace(value, @"%20", string.Empty);value = Regex.Replace(value, @"--", string.Empty);value = Regex.Replace(value, @"==", string.Empty);value = Regex.Replace(value, @"<", string.Empty);value = Regex.Replace(value, @">", string.Empty);value = Regex.Replace(value, @"%", string.Empty);return value;}}}
