C#网上书店登录界面实现——正则表达式（软工笔记）

一、实现环境

C#、window10、vs2019
数据库SQL Server (SQLEXPRESS)

二、界面要求

1 、连接本地数据库
2 、用户名&＃xff1a;用户名可以是数字、下划线&＃xff08;不能开头&＃xff09;、字母、汉字。
3 、密码&＃xff1a;密码不能小于8或大于16&＃xff0c;密码必须包含数字和字母。
4 、用到的命名空间&＃xff1a;

using System.Data.SqlClient;
using System.Text.RegularExpressions;


5 、用户名正则代码如下&＃xff1a;

^(?!_)(?!.*?_$)[a-zA-Z0-9_\u4e00-\u9fa5]&＃43;$


6、 密码正则代码如下&＃xff1a;

^(?![0-9]&＃43;$)(?![a-zA-Z]&＃43;$)[0-9A-Za-z]{8,16}$


三、具体实现

1、界面布局

密码文本框password属性改为 *

checkbox代码实现部分如下&＃xff1a;

private void checkBox1_CheckedChanged(object sender, EventArgs e){if (checkBox1.Checked){textBox2.PasswordChar &＃61; &＃39;\0&＃39;;}else{textBox2.PasswordChar &＃61; &＃39;*&＃39;;}}


2、运行效果

3、登录实现代码&＃xff1a;

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;
namespace bookstore_login
{public partial class Form1 : Form{public Form1(){InitializeComponent();}private SqlConnection conn &＃61; null;private SqlCommand cmd &＃61; null;private SqlDataReader reader &＃61; null;private string connstring &＃61; &＃64;"Data Source&＃61;(localdb)\MSSQLLocalDB;Initial Catalog&＃61;loginDB;Integrated Security&＃61;True;Connect Timeout&＃61;30;Encrypt&＃61;False;TrustServerCertificate&＃61;False;ApplicationIntent&＃61;ReadWrite;MultiSubnetFailover&＃61;False";private void button2_Click(object sender, EventArgs e){try{conn &＃61; new SqlConnection(connstring);conn.Open();cmd &＃61; conn.CreateCommand();cmd.CommandText &＃61; "SELECT login_table.* FROM login_table where(name&＃61;&＃64;name) and (password&＃61;&＃64;password)";cmd.Parameters.AddWithValue("&＃64;name", textBox1.Text.Trim());cmd.Parameters.AddWithValue("&＃64;password", textBox2.Text.Trim());reader &＃61; cmd.ExecuteReader();if (reader.Read()){MessageBox.Show("登陆成功", "登陆成功", MessageBoxButtons.OK, MessageBoxIcon.Information);}else{MessageBox.Show("用户名、密码不正确", "登陆失败", MessageBoxButtons.OK, MessageBoxIcon.Error);}}catch (Exception ex){MessageBox.Show(ex.Message, "open error", MessageBoxButtons.OK);}finally{if (reader !&＃61; null){reader.Close();}if (conn.State &＃61;&＃61; ConnectionState.Open){conn.Close();}}}private void checkBox1_CheckedChanged(object sender, EventArgs e){if (checkBox1.Checked){textBox2.PasswordChar &＃61; &＃39;\0&＃39;;}else{textBox2.PasswordChar &＃61; &＃39;*&＃39;;}}private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e){Form_注册 reg &＃61; new Form_注册();reg.ShowDialog();}}
}

4、注册实现代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.Text.RegularExpressions;namespace bookstore_login
{public partial class Form_注册 : Form{public Form_注册(){InitializeComponent();}private static int agree &＃61; 0;private SqlConnection conn &＃61; null;private SqlCommand cmd &＃61; null;private SqlDataReader reader &＃61; null;private string connstring &＃61; &＃64;"Data Source&＃61;(localdb)\MSSQLLocalDB;Initial Catalog&＃61;loginDB;Integrated Security&＃61;True;Connect Timeout&＃61;30;Encrypt&＃61;False;TrustServerCertificate&＃61;False;ApplicationIntent&＃61;ReadWrite;MultiSubnetFailover&＃61;False";private int checkname(){Regex re &＃61; new Regex("^(?!_)(?!.*?_$)[a-zA-Z0-9_\u4e00-\u9fa5]&＃43;$");Regex re_ &＃61; new Regex("^(?!_)");int flag &＃61; 1;if ( textBox2.Text.Length < 6){MessageBox.Show("用户名不能小于6");flag &＃43;&＃61; 1;}else if (textBox2.Text.Length > 12){MessageBox.Show("用户名不能大于12");flag &＃43;&＃61; 1;}else if (!re_.IsMatch(textBox2.Text.ToString())){MessageBox.Show("用户名下划线不能放在开头");flag &＃43;&＃61; 1;}else if (!re.IsMatch(textBox2.Text.ToString())){MessageBox.Show("含有非法字符");flag &＃43;&＃61; 1;}return flag;}private int checkpd(){Regex re &＃61; new Regex("^(?![0-9]&＃43;$)(?![a-zA-Z]&＃43;$)[0-9A-Za-z]{8,16}$");int flag &＃61; 1;if (textBox3.Text.Length<8){MessageBox.Show("密码不能小于8");flag &＃43;&＃61; 1;}else if (textBox3.Text.Length>16){MessageBox.Show("密码不能大于16");flag &＃43;&＃61; 1;}else if (!re.IsMatch(textBox3.Text.ToString())){MessageBox.Show("密码必须是字母数字的结合");flag &＃43;&＃61; 1;}return flag;}private void button1_Click(object sender, EventArgs e){if (checkname()&＃61;&＃61;1&&checkpd()&＃61;&＃61;1){if (agree &＃61;&＃61; 1){try{conn &＃61; new SqlConnection(connstring);conn.Open();cmd &＃61; conn.CreateCommand();cmd.CommandText &＃61; "INSERT INTO login_table (name, password) VALUES (&＃64;name, &＃64;password)";cmd.Parameters.AddWithValue("&＃64;name", textBox2.Text.Trim());cmd.Parameters.AddWithValue("&＃64;password", textBox3.Text.Trim());if (String.IsNullOrEmpty(textBox2.Text)){MessageBox.Show("用户名不能为空&＃xff01;");return;}if (String.IsNullOrEmpty(textBox3.Text)){MessageBox.Show("密码不能为空&＃xff01;");return;}int n &＃61; cmd.ExecuteNonQuery();if (n > 0){MessageBox.Show("成功注册,请登录", "insert ok", MessageBoxButtons.OK, MessageBoxIcon.Information);}else{MessageBox.Show("注册失败", "insert error", MessageBoxButtons.OK, MessageBoxIcon.Error);}}catch (Exception ex){MessageBox.Show(ex.Message, "open error", MessageBoxButtons.OK);}finally{if (conn.State &＃61;&＃61; ConnectionState.Open){conn.Close();}}this.Close();}else{MessageBox.Show("请勾选用户协议和隐私声明");}} }private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e){this.Close();}private void checkBox1_CheckedChanged(object sender, EventArgs e){agree &＃61; 1;}}
}

四、遇到的问题及待解决的问题

1、建议使用.Net Framwork框架&＃xff0c;如果使用.NET Core框架&＃xff0c;导入using System.Data.SqlClient&＃xff0c;使用时会报错&＃xff0c;需要手动添加System.Data.SqlClient&＃xff0c;具体操作见https://blog.csdn.net/sjtuxx_lee/article/details/94338908主要操作内容如下

控制台输入命令如下&＃xff1a;

PM> Install-Package System.Data.Common
PM> Install-Package System.Data.SqlClient

2、界面添加图片时&＃xff0c;一定要添加到backgroundimage属性&＃xff0c;然后再把backgroundimagelayout改为stretch&＃xff0c;不要添加到image属性&＃xff0c;这样才能完整的显示图片内容。
3、SQL Server(SQLEXPRESS)&＃xff0c;注册&＃xff08;插入数据&＃xff09;时&＃xff0c;用户名使用汉字时&＃xff0c;存入数据库后&＃xff0c;汉字会出现乱码&＃xff0c;没有找到数据库如何设置编码&＃xff0c;还是避免使用汉字吧&＃xff0c;希望会的大佬可以评论教一下。
4、未实现功能&＃xff1a;本想在用户名和密码文本框内加入隐藏提示内容&＃xff0c;像下图一样&＃xff0c;
通过焦点事件控制提示事件&＃xff0c;由于时间、技术原因未能实现该功能&＃xff0c;有大佬知道的话可以发个链接。