private void Form1_FormClosing(object sender, FormClosingEventArgs e) { DialogResult dr; dr = MessageBox.Show("确认退出吗?", "确认对话框", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2); if (dr == DialogResult.Yes) { Mainform main = new Mainform(); main.Show(); this.Close(); } else { e.Cancel = true; } }
private void button1_Click(object sender, EventArgs e) { if (NametextBox.Text == "") { MessageBox.Show("请输入用户名", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning); } else { if (PasswordtextBox.Text == "") { MessageBox.Show("请输入密码", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning); } else { try { //实例化数据库连接对象,并设置连接到数据库的参数 //SqlConnection sqlConn = new SqlConnection("server=.;database=BOOK_MANAGE_SYSTEM;Trusted_Connection=SSPI"); SqlConnection sqlConn = DBconnect.BooksystemCon(); sqlConn.Open(); //打开连接 if (sqlConn.State == ConnectionState.Open) { string sql = "select * from USERS where NAME='" + NametextBox.Text + "' and PASSWORDS='" + PasswordtextBox.Text + "'"; // MessageBox.Show(sql); SqlCommand cmd = new SqlCommand(sql, sqlConn); SqlDataReader sdr = cmd.ExecuteReader(); //使用ExecuteReader创建SqlDataReader对象 sdr.Read(); //读取/前进到下一条记录 if (sdr.HasRows) //查询结果集中是否有值 { // MessageBox.Show("恭喜!登录成功"); sdr.Close(); cmd = new SqlCommand("select * from USERS where NAME='" + NametextBox.Text + "'", sqlConn); SqlDataReader sdr1 = cmd.ExecuteReader(); sdr1.Read(); string UserPower = sdr1["POWERS"].ToString().Trim(); string UserId = sdr1["U_ID"].ToString().Trim(); sqlConn.Close(); Mainform main = new Mainform(); main.power = UserPower; main.U_ID = UserId; main.Names = NametextBox.Text; main.Times = DateTime.Now.ToShortDateString(); main.Show(); this.Hide(); } else { MessageBox.Show("用户名或密码错误"); } } else { MessageBox.Show("数据库连接失败!"); } } catch (Exception ex) { MessageBox.Show(ex.Message); } } } }
private void button1_Click(object sender, EventArgs e) { if (IDtextBox.Text == "") { MessageBox.Show("请输入ID", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning); } else { if (NametextBox.Text == "") { MessageBox.Show("请输入用户名", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning); } else { if (PasswordtextBox.Text == "") { MessageBox.Show("请输入密码", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning); } else { if (DeparttextBox.Text == "") { MessageBox.Show("请输入您所在的班级", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning); } //用户输入规范检查完毕,开始连接数据库 try { //实例化数据库连接对象,并设置连接到数据库的参数 // SqlConnection sqlConn = new SqlConnection("server=.;database=BOOK_MANAGE_SYSTEM;Trusted_Connection=SSPI"); SqlConnection sqlConn = DBconnect.BooksystemCon(); sqlConn.Open(); //打开连接 if (sqlConn.State == ConnectionState.Open) { //检查用户是否正在借阅该书 SqlCommand cmd1 = new SqlCommand("select U_ID from USERS where U_ID ='" + IDtextBox.Text + "'", sqlConn); SqlDataReader sdr1 = cmd1.ExecuteReader(); sdr1.Read(); if (sdr1.HasRows) { MessageBox.Show("sorry!该用户ID 已经存在了哦!请换个ID 号进行注册"); sqlConn.Close(); } else { sqlConn.Close(); //将注册信息写入数据库 string sql = "insert into USERS (U_ID,NAME,DEPARTMENT,PASSWORDS) VALUES('" + IDtextBox.Text + "','" + NametextBox.Text + "','" + DeparttextBox.Text + "','" + PasswordtextBox.Text + "')"; // MessageBox.Show(sql); SqlCommand cmd = new SqlCommand(sql, sqlConn); sqlConn.Open(); cmd.ExecuteNonQuery(); MessageBox.Show("注册成功", "提示", MessageBoxButtons.OK, MessageBoxIcon.Asterisk); //写入数据库完毕,将用户信息初始化到系统 Mainform main = new Mainform(); main.power = "0"; main.Names = NametextBox.Text; main.Times = DateTime.Now.ToShortDateString(); main.Show(); this.Hide(); sqlConn.Close(); } } else { MessageBox.Show("数据库连接失败!"); } } catch (Exception ex) { MessageBox.Show(ex.Message); } } } } }