注册 传值

  //添加
       public void insert(string uid, string pwd, string nickname, bool sex, string memo, int level)
       {
           _cmd.CommandText = "insert into YouKe values(@uid,@pwd,@nickname,@sex,@memo,@level)";
           _cmd.Parameters.Clear();
           _cmd.Parameters.AddWithValue("@uid",uid);
           _cmd.Parameters.AddWithValue("@pwd",pwd);
           _cmd.Parameters.AddWithValue("@nickname",nickname);
           _cmd.Parameters.AddWithValue("@sex",sex);
           _cmd.Parameters.AddWithValue("@memo",memo);
           _cmd.Parameters.AddWithValue("@level",level);
           _conn.Open();
            _cmd.ExecuteNonQuery();
           
           _conn.Close();
          
       }

/读取用户信息

public List<youke> select(string uid)
{
_cmd.CommandText = "select * from YouKe where uid=@uid";
_cmd.Parameters.Clear();
_cmd.Parameters.AddWithValue("@uid", uid);
_conn.Open();
_dr = _cmd.ExecuteReader();

List<youke> list = new List<youke>();
if (_dr.HasRows)
{
while (_dr.Read())
{
youke data = new youke();
data.Uid = _dr[0].ToString();
data.Pwd = _dr[1].ToString();
data.Nickname = _dr[2].ToString();
data.Sex = Convert.ToBoolean(_dr[3]);
data.Memo = _dr[4].ToString();
data.Level = Convert.ToInt32(_dr[5]);
list.Add(data);
}
}
return list;
_conn.Close();
}

public bool select1(string uid)
       {
           try
           {
               _cmd.CommandText = "select * from YouKe where uid=@uid";
               _cmd.Parameters.Clear();
               _cmd.Parameters.AddWithValue("@uid", uid);
               _conn.Open();
               _dr = _cmd.ExecuteReader();
               if (_dr.Read())
               {
                   return true;
               }
               else
               {
                   return false;
               }


           }

           finally
           {
               _conn.Close();
           }

1、 注册：

   private void button1_Click(object sender, EventArgs e)
        {
            insert();
            MessageBox.Show("注册成功！");

            this.Close();
        }
        public void insert()
        {
            //添加用户数据
            string uid = txtuid.Text;
            string pwd = txtpwd.Text;
            string nickname = txtname.Text;
            bool sex;
            if (radnan.Checked)
            {
                sex = true;
            }
            else
            {
                sex = false;
            }
            string memo = txtmemo.Text;
            int level = 0;
          youkeDA da=new youkeDA();
          da.insert(uid,pwd,nickname,sex,memo,level);
     
            
        }


        private void txtuid_Leave(object sender, EventArgs e)
        {
            youkeDA da = new youkeDA();
            da.select1(txtuid.Text);
           这里可以判断是否已注册了

2、 登录传值：login  传值到  youxi  界面

login界面内容：

   public string uidname;
        private void button1_Click(object sender, EventArgs e)
        {
            string uid = textBox1.Text;
            string pwd = textBox2.Text;
            if (uid != "" && pwd != "")
            {
                youkeDA da = new youkeDA();
                
                if (da.select1(uid))
                {
                    uidname = uid;
                    this.DialogResult = DialogResult.OK;
                    this.Close();
                }
                else
                {
                    MessageBox.Show("错误");
                }
            }
            else
            {
                MessageBox.Show("错误，不能为空");
            }
           
        }

youxi界面：

    public youxi()
        {
            InitializeComponent();
        }
        //构造函数
        public youxi(string zhenghao)
        {
            InitializeComponent();
            uid = zhenghao;
            
        }


 //加载
        private void Form1_Load(object sender, EventArgs e)
        {
            InitializeLayout(4, 4, 80, 4, 1);
            if (uid != "")
            {
                youkeDA da = new youkeDA();
                List<youke> list = da.select(uid);
                label11.Text = list[0].Uid;
                label10.Text = list[0].Nickname;
            }
}

program界面进行修改：

  static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
           // Application.Run(new login());
            login log = new login();
            if (log.ShowDialog() == DialogResult.OK)
            {
                Application.Run(new youxi(log.uidname));
            }

        }