private void button1_Click_1(object sender, EventArgs e) { name = textBox1.Text.Trim(); //获取文本框数值 role = this.comboBox1.SelectedItem.ToString(); //对选择框进行设置 未选报错 if (name == "" || textBox2.Text.Trim() == "" || role == "") //数值为空跳出提示 { MessageBox.Show("请将信息输入完整!"); } else { SqlConnection conn = new SqlConnection(Form1.connectionString); //创建对象 conn.Open(); //打开数据库 if (role == "管理员") { string sql = "select manname,manpasswd from manager where role='管理员'and manname='" + name + "' and manpasswd='" + textBox2.Text.Trim() + "'"; SqlDataAdapter adp = new SqlDataAdapter(sql, conn); //数据库命令 DataSet ds = new DataSet(); //初始化 adp.Fill(ds); //刷新 if (ds.Tables[0].Rows.Count > 0) { conn.Close(); Form2 mainframe = new Form2(); mainframe.BringToFront(); mainframe.Show(); this.Hide(); } else { MessageBox.Show("用户名或者密码错误!"); } } if (role == "学生") { string sql1 = "select stuxuehao,stupasswd from student where role='学生'and stuxuehao='" + name + "' and stupasswd='" + textBox2.Text.Trim() + "'"; SqlDataAdapter adp = new SqlDataAdapter(sql1, conn); //数据库命令 DataSet ds = new DataSet(); //初始化 adp.Fill(ds); //刷新 if (ds.Tables[0].Rows.Count > 0) //克隆查询消息,并将信息带入带下一个from去 { conn.Close(); Form3 mainframe = new Form3(); mainframe.BringToFront(); mainframe.Show(); this.Hide(); } else { MessageBox.Show("用户名或者密码错误!"); } } } }
private void searchbookBtn_Click(object sender, EventArgs e) { if (form3 != null) { form3.BringToFront(); } else { form3 = new Form3(); form3.Show(); if (form2 != null) { form2.Hide(); form2 = null; } } }