管理系统开发二： winforml登录界面sql数据查询和修改

以你之姓@ 2022-03-08 03:10 263阅读 0赞

接着上一张：[https://blog.csdn.net/m0\_37583098/article/details/88546146][https_blog.csdn.net_m0_37583098_article_details_88546146]

这篇主要是登录界面

我先将winform与数据库的常用方法 封装了一下 另添加创建类

using System;
    using System.Collections.Generic;
    using System.Data;
    using System.Data.SqlClient;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace csdn
    {
      public  class  SQLHelper
        {
            public static string connString = "server=.;database=SMDB;user=sa;pwd=12345";
            public static bool OpenSQL()
            {
                SqlConnection conn = new SqlConnection(connString);
                conn.Open();
                try
                {
                    return true;
                }
                catch (Exception)
                {
                    return false;
                    throw;
                }
            }
            /// <summary>
            /// 执行增、删、改操作
            /// </summary>
            /// <param name="sql"></param>
            /// <returns></returns>
            public static int Update(string sql)
            {
                SqlConnection conn = new SqlConnection(connString);
                SqlCommand cmd = new SqlCommand(sql, conn);
                try
                {
                    conn.Open();
                    int result = cmd.ExecuteNonQuery();
                    return result;
                }
                catch (Exception ex)
                {
                    //写入系统日志
                    throw new Exception(ex.Message);
                }
                finally
                {
                    conn.Close();
                }
            }
            /// <summary>
            /// 获取单一结果查询
            /// </summary>
            /// <param name="sql"></param>
            /// <returns></returns>
            public static object GetSingleResult(string sql)
            {
                SqlConnection conn = new SqlConnection(connString);
                SqlCommand cmd = new SqlCommand(sql, conn);
                try
                {
                    conn.Open();
                    object result = cmd.ExecuteScalar();
                    return result;
                }
                catch (Exception ex)
                {
                    //写入系统日志
    
                    throw ex;
                }
                finally
                {
                    conn.Close();
                }
            }
            /// <summary>
            /// 返回一个结果集的查询
            /// </summary>
            /// <param name="sql"></param>
            /// <returns></returns>
            public static SqlDataReader GetReader(string sql)
            {
                SqlConnection conn = new SqlConnection(connString);
                SqlCommand cmd = new SqlCommand(sql, conn);
                try
                {
                    conn.Open();
                    return cmd.ExecuteReader(CommandBehavior.CloseConnection);
                }
                catch (Exception ex)
                {
                    //写入系统日志
    
                    conn.Close();
                    throw ex;
                }
            }
        }
    }

2.登录数据库

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzM3NTgzMDk4_size_16_color_FFFFFF_t_70][]

3. 创建管理员表

![20190314103510536.png][]

2.然后回到VS  创建登录界面

![20190314103200491.png][]

添加脚本验证输入字符不为空

//数据验证
                if (this.txtLoginId.Text.Trim().Length==0) {
                    MessageBox.Show("请输入登录账号","登录提示");
                    this.txtLoginId.Focus();
                    return;
                }

4.创建数据访问类

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    
    namespace Models
    {
        public class Admin
        {
            /// <summary>
            /// 登录账号
            /// </summary>
            public int LoginId { get; set; }
            /// <summary>
            /// 用户名
            /// </summary>
            public string AdminName { get; set; }
            /// <summary>
            /// 登录密码
            /// </summary>
            public string LoginPwd { get; set; }
        }
    }

5.//封装用户信息到用户对象

Admin objAdmin = new Admin()
                {
                    LoginId = Convert.ToInt32(this.txtLoginId.Text.Trim()),
                    LoginPwd = this.txtLoginPwd.Text.Trim()
                };

6.提交用户

//提交用户信息
                try
                {
                    objAdmin = objAdminService.AdminLogin(objAdmin);
                    if (objAdmin == null)
                    {
                        MessageBox.Show("登录账号或密码错误！！", "登录提示");
                    }
                    else {
                        //保存登录对象
                        sqlLog.WriteSQLLog(objAdmin .AdminName+ "用户登录！");
                        Program.currAdmin = objAdmin;
                        this.DialogResult = DialogResult.OK;
                    }
                }
                catch (Exception ex) 
                {
                    MessageBox.Show(ex.Message,"登录失败！！");
                }
            }

说一下 这里的objAdminService.AdminLogin();是在另外一个类里创建           命名空间啥的大家自己注意点改成自己的

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Data;
    using System.Data.SqlClient;
    using Models;
    using System.Data.SqlServerCe;
    
    namespace DAL
    {
        
        /// <summary>
    /// 管理员数据访问类
    /// </summary>
        public class AdminService
        {
            /// <summary>
            /// 根据用户名或密码登录
            /// </summary>
            /// <param name="objAdmin"></param>
            /// <returns></returns>
            public Admin AdminLogin(Admin objAdmin)
            {
                string sql = "select AdminName from Admins where LoginId={0} and LoginPwd='{1}'";
                sql = string.Format(sql, objAdmin.LoginId, objAdmin.LoginPwd);
                try
                {
                    SqlCeDataReader objReader = SQLHelper.GetReader(sql);
                    if (objReader.Read())
                    {
                        objAdmin.AdminName = objReader["AdminName"].ToString();
                    }
                    else
                    {
                        objAdmin = null;
                    }
                    objReader.Close();
                    return objAdmin;
                }
                catch (Exception ex)
                {
                    throw new Exception("数据访问发生异常：" + ex.Message);
                }
            }
    
            /// <summary>
            /// 修改密码
            /// </summary>
            /// <param name="loginid">登录ID</param>
            /// <param name="newPwd">新密码</param>
            /// <returns></returns>
            public int ModifyPwd(string loginid,string newPwd) {
                string sql = "update Admins set LoginPwd='{0}' where LoginId={1}";
                sql = string.Format(sql,newPwd,loginid);
                return SQLHelper.Update(sql);
            }
            /// <summary>
            /// 密码找回
            /// </summary>
            /// <param name="objAdmin"></param>
            /// <returns></returns>
            public Admin FindAdminpwd(string LoginId)
            {
                string sql = "select * from Admins where LoginId={0}";
                sql = string.Format(sql, LoginId);
                try
                {
                    SqlDataReader objReader = SQLHelper.GetReader(sql);
                    Admin Login = new Admin();
                    if (objReader.Read())
                    {
                        Login.AdminName = objReader["AdminName"].ToString();
                        Login.LoginPwd = objReader["LoginPwd"].ToString();
                    }
                    objReader.Close();
                    return Login;
                }
                catch (Exception ex)
                {
                    throw new Exception("数据访问发生异常：" + ex.Message);
                }
            }
        }
    }

SQLHelper.GetReader(sql);就是我这篇文章最先添加的那个方法

关闭按钮功能

//关闭
            private void btnClose_Click(object sender, EventArgs e)
            {
                this.Close(); 
            }

管理系统开发三： winforml查询界面  sql数据录入

[https_blog.csdn.net_m0_37583098_article_details_88546146]: https://blog.csdn.net/m0_37583098/article/details/88546146
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzM3NTgzMDk4_size_16_color_FFFFFF_t_70]: /images/20220308/b4333445d5a142018af04f99e583ab44.png
[20190314103510536.png]: /images/20220308/2cbd73c5bf6c43b59b591369c84bdc01.png
[20190314103200491.png]: /images/20220308/c20a06d2a5444ac2a0c79a072e27b26d.png