简单的权限管理系统

【实例简介】
【实例截图】
【核心代码】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.Security;
using System.Security.Cryptography;
using System.Configuration;
namespace System_Manage
{
    public partial class Frm_Users : Form
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["conn"].ConnectionString);
        public Frm_Users()
        {
            InitializeComponent();
            //没置不自动产生行
            Dgv_Users.AutoGenerateColumns = false;
            //初始化绑定所有用户
            Bind_Users_All();
        }
        /// <summary>
        /// 绑定所有用户
        /// </summary>
        private void Bind_Users_All()
        {
            try
            {
                string sql = "select * from System_users";
                SqlDataAdapter adp = new SqlDataAdapter(sql, conn);
                DataSet ds = new DataSet();
                conn.Open();
                adp.Fill(ds, "users");
                Dgv_Users.DataSource = ds.Tables["users"];
                btn_ok.Text = "添加";
                tb_username.Text = "";
                tb_username.ReadOnly = false;
                tb_usertruename.Text = "";
                tb_ukey.Text = "";
                btn_delete.Enabled = false;

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
            finally
            {
                conn.Close();
            }
        }
        /// <summary>
        /// 添加新用户
        /// </summary>
        /// <param name="username"></param>
        /// <param name="usertruename"></param>
        /// <param name="userpass"></param>
        /// <param name="userkey"></param>
        private void User_Add(string username, string usertruename, string userpass, string userkey, int isvalid, int isadmin, string userlogintime)
        {
            try
            {
                //检测新用户
                string sql_check = "select user_name from system_users where user_name='" username "'";
                SqlDataAdapter adp_check = new SqlDataAdapter(sql_check, conn);
                DataSet ds_check = new DataSet();
                conn.Open();
                adp_check.Fill(ds_check);
                //检测新用户
                if (ds_check.Tables[0].Rows.Count != 0)
                {
                    MessageBox.Show("用户名重复！");
                }
                else
                {
                    //注册新用户
                    string sql = "insert into System_users(user_name,user_pass,user_truename,user_key,isvalid,is_admin,user_logintime)values('" username "','" userpass "','" usertruename "','" userkey "'," isvalid "," isadmin ",'" userlogintime "')";
                    SqlCommand cmd = new SqlCommand(sql, conn);

                    int i = cmd.ExecuteNonQuery();
                    if (i != 1)
                    {
                        MessageBox.Show("添加失败,请联系系统管理员！");
                    }
                    else
                    {
                        //添加成功，清空文本框
                        MessageBox.Show("添加成功!");
                        tb_username.Text = "";
                        tb_usertruename.Text = "";
                        tb_ukey.Text = "";
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
            finally
            {
                conn.Close();
            }
        }
        /// <summary>
        /// 修改用户信息
        /// </summary>
        /// <param name="usertruename"></param>
        /// <param name="userpass"></param>
        /// <param name="userkey"></param>
        /// <param name="userid"></param>
        /// <param name="isvalid"></param>
        /// <param name="isadmin"></param>
        private void User_Modify(string usertruename, string userpass, string userkey, string userid, int isvalid, int isadmin)
        {
            try
            {

                //修改用户信息
                string sql = "";
                //如果密码为空，则不修改密码
                if (tb_userpass.Text.ToString().Trim() == "")
                {
                    sql = "update System_users set user_truename='" usertruename "',user_key='" userkey "',isvalid=" isvalid ",is_admin=" isadmin " where user_id='" userid "'";
                }
                //如果密码柜不为空，则同时修改密码
                else
                {
                    sql = "update System_users set user_truename='" usertruename "',user_pass='" userpass "',user_key='" userkey "',isvalid=" isvalid ",is_admin=" isadmin " where user_id='" userid "'";
                }
                SqlCommand cmd = new SqlCommand(sql, conn);
                conn.Open();
                int i = cmd.ExecuteNonQuery();
                if (i != 1)
                {
                    MessageBox.Show("修改失败，请联系系统管理员！");
                    btn_ok.Text = "添加";

                }
                else
                {
                    //添加成功，清空文本框
                    MessageBox.Show("修改成功！");
                    tb_username.Text = "";
                    tb_usertruename.Text = "";
                    tb_ukey.Text = "";
                    cb_isvalid.Checked = true;
                    btn_ok.Text = "添加";
                }

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
            finally
            {
                conn.Close();
            }
        }
        private void btn_ok_Click(object sender, EventArgs e)
        {
            //检测用户名是否为空
            if (String.IsNullOrEmpty(tb_username.Text) || tb_username.Text.Trim() == string.Empty)
            {
                MessageBox.Show("请输入用户名");
                tb_username.Focus();
                return;
            }
            //检测真实姓名是否为空
            if (String.IsNullOrEmpty(tb_usertruename.Text) || tb_usertruename.Text.Trim() == string.Empty)
            {
                MessageBox.Show("请输入真实姓名");
                tb_usertruename.Focus();
                return;
            }
            string username = tb_username.Text.ToString().Trim();
            string usertruename = tb_usertruename.Text.ToString().Trim();
            string userkey = tb_ukey.Text.ToString().Trim();
            //密码MD5加密
            byte[] result = Encoding.Default.GetBytes(this.tb_userpass.Text.Trim());
            MD5 md5 = new MD5CryptoServiceProvider();
            byte[] output = md5.ComputeHash(result);
            string userpass = BitConverter.ToString(output).Replace("-", "");
            string userid = lb_userid.Text.ToString().Trim();
            int isvalid = cb_isvalid.Checked ? 1 : 0;
            int isadmin = cb_isadmin.Checked ? 1 : 0;
            if (btn_ok.Text == "添加")
            {
                DateTime getdate;
                string userlogintime = "";
                //取系统时间作为登陆时间
                try
                {
                    string sql = "select getdate()";
                    SqlCommand cmd = new SqlCommand(sql, conn);
                    conn.Open();
                    getdate = Convert.ToDateTime(cmd.ExecuteScalar());
                    userlogintime = getdate.ToString();
                }

                catch (Exception ex)
                {
                    MessageBox.Show(ex.ToString());
                }
                finally
                {
                    conn.Close();
                }

                //调用用户注册
                User_Add(username, usertruename, userpass, userkey, isvalid, isadmin, userlogintime);

            }
            else if (btn_ok.Text == "修改")
            {
                User_Modify(usertruename, userpass, userkey, userid, isvalid, isadmin);
            }

            //重新绑定所有用户
            Bind_Users_All();
        }
        /// <summary>
        /// 双击单元格自动显示用户信息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Dgv_Users_CellContentDoubleClick(object sender, DataGridViewCellEventArgs e)
        {
            try
            {
                string user_id = Dgv_Users.CurrentRow.Cells[0].Value.ToString();
                string sql = "select user_name,user_truename,user_key,user_id,isvalid,is_admin from system_users where user_id='" user_id "'";
                SqlCommand cmd = new SqlCommand(sql, conn);
                conn.Open();
                SqlDataReader dr = cmd.ExecuteReader();
                if (dr.Read())
                {
                    tb_username.Text = dr[0].ToString();
                    tb_usertruename.Text = dr[1].ToString();
                    tb_userpass.Text = "";
                    tb_ukey.Text = dr[2].ToString();
                    lb_userid.Text = dr[3].ToString();
                    cb_isvalid.Checked = bool.Parse(dr[4].ToString());
                    cb_isadmin.Checked = bool.Parse(dr[5].ToString());

                    btn_ok.Text = "修改";
                    tb_username.ReadOnly = true;
                    btn_delete.Enabled = true;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
            finally
            {
                conn.Close();
            }
        }
        /// <summary>
        /// 刷新信息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            Bind_Users_All();
        }
        /// <summary>
        /// 删除用户
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btn_delete_Click(object sender, EventArgs e)
        {
            try
            {
                string userid = lb_userid.Text.ToString();
                string sql = "delete from system_users where user_id='" userid "'";
                SqlCommand cmd = new SqlCommand(sql, conn);
                conn.Open();
                int i = cmd.ExecuteNonQuery();
                if (i == 1)
                {
                    MessageBox.Show("删除成功！");
                }
                else
                {
                    MessageBox.Show("删除失败！");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
            finally
            {
                conn.Close();
            }
            Bind_Users_All();
        }

        private void Dgv_Users_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

        }

    }
}