private void ReturnGV_Click(object sender, EventArgs e) { this.Hide(); ManHinhChinh manhinhchinh = new ManHinhChinh(); manhinhchinh.ShowDialog(); }
private void btnDangnhap_Click(object sender, EventArgs e) { SqlConnection connection = new SqlConnection(@"Data Source=DESKTOP-C33GCG4;Initial Catalog=quanly_Hs_Gv_THPT_3F;Integrated Security=True"); try { connection.Open(); string taiKhoan = textBox1.Text; string matKhau = textBox2.Text; string sql = "select * from DANGNHAP where TaiKhoan = '" + taiKhoan + "' and MatKhau = '" + matKhau + "'"; SqlCommand cmd = new SqlCommand(sql, connection); SqlDataReader dta = cmd.ExecuteReader(); if (dta.Read() == true) { this.Hide(); ManHinhChinh manHinhChinh = new ManHinhChinh(); manHinhChinh.ShowDialog(); } else { MessageBox.Show("Đăng nhập thất bại!"); } } catch (Exception) { MessageBox.Show("Lỗi kết nối"); } }