try
                {
                    conn = new OleDbConnection(myconn);
                    conn.Open();
                    cmd = new OleDbCommand("select * from Student_Login where Sno = '" + textUser.Text.Trim() + "'" + "'and Password='" + textPwd.Text.Trim() + "' ", conn);
                    read = cmd.ExecuteReader();
                    //该学生信息存在且密码正确
                    if (read.Read())
                    {
                        //进入学生界面
                        Form2 form2 = new Form2();
                        form2.Show();
                    }
                    else  //没有该学生的信息
                    {
                        MessageBox.Show("不存在该学生或密码不正确!");
                    }
                }
                catch (Exception ee)
                {
                    MessageBox.Show(ee.ToString());
                }
                finally
                {
                        read.Close();
                        conn.Close();  //关闭数据库连接
                  
                }

[ 本帖最后由 清波无雯 于 2014-9-7 11:20 编辑 ]

Sno = '" + textUser.Text.Trim() + "'" + "'and Password='" + textPwd.Text.Trim() + "'就是这句错了，textUser.Text.Trim()、textPwd.Text.Trim()获取的已经是字符串形式了。

恩，谢谢，那里是出错了，不过修改后还是有点问题，还得在Sno前面加上Student才可以运行

貌似楼主应该跟我一样 在学C#面对象编程吧 。。

路过哈哈