2个文本框(用户名&&密码)
2个按钮（登陆&&注册）
连接数据库和操作
知道的告诉下
代码越详细越好
先谢了

private void button1_Click(object sender, EventArgs e)
        {
            string uname = this.textBox1.Text.ToString();
            string upassword = this.textBox2.Text.ToString();
            SqlConnection thisconnection = new SqlConnection(@"Server=AL;Integrated Security=True;" + "DataBase=登陆界面");
            thisconnection.Open();
            SqlCommand thiscommand = thisconnection.CreateCommand();
             = "select uname,upassword from yh where uname='" + uname + " '";
            SqlDataReader thisreader = thiscommand.ExecuteReader();
            if (thisreader.Read())
            {
                if (thisreader["upassword"].ToString().Trim() == upassword)
                {
                    MessageBox.Show("恭喜您登陆成功！", "登陆成功！", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    yhxx tt = new yhxx();
                    tt.Show();

                }
                else { MessageBox.Show("密码错误，请重新输入！", "错误", MessageBoxButtons.OK, MessageBoxIcon.Information); }

            }
            else { MessageBox.Show("此用户不存在，请您注册！", "注册", MessageBoxButtons.OK, MessageBoxIcon.Information); }
            thisconnection.Close();
            thisreader.Close();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            zhuce ss = new zhuce();
            ss.Show();
        }

应该是连接的2个窗体的对象名

登录成功和点击注册后弹出的窗体

string uname = this.textBox1.Text.ToString();
string upassword = this.textBox2.Text.ToString();
这里要用到ToString方法？

2楼的程序基本上满足LZ的需求了，就是注册的代码没写。

为什么不用存储过程呢？
直接用SQL语句安全吗？

用存储过程LZ能看到吗？

LZ连数据库基本操作都不懂，还用存储过程

建议LZ先去学学数据库操作啊