我创建一个新的注册页面成功。每当我输入用户名和密码，并点击提交按钮，它保存的凭据，但这里的问题是两次输入的数据。

private void sbmtbtn_Click(object sender, EventArgs e)
    {
        if (usrnmtxtbx.Text != "")
        {
            if (pswdtxtbx.Text != "")
            {
                if (cnfrmtxtbx.Text != "")
                {
                    if (pswdtxtbx.Text == cnfrmtxtbx.Text)
                    {
                        MySqlConnection Con = new MySqlConnection(ConnectionString);
                        MySqlCommand Cmd;
                        Con.Open();
                        try
                        {
                            Cmd = Con.CreateCommand();
                            Cmd.CommandText = "INSERT IGNORE INTO signup(username, password,confirm) VALUES(@username,@password,@confirm)";
                            Cmd.Parameters.Add("@username", MySqlDbType.VarChar).Value = usrnmtxtbx.Text;
                            Cmd.Parameters.Add("@password", MySqlDbType.VarChar).Value = pswdtxtbx.Text;
                            Cmd.Parameters.Add("@confirm", MySqlDbType.VarChar).Value = cnfrmtxtbx.Text;

                            DataTable table = new DataTable();
                            MySqlDataAdapter adapter = new MySqlDataAdapter();
                            adapter.SelectCommand = Cmd;
                            adapter.Fill(table);
                            Cmd.ExecuteNonQuery();
                            MessageBox.Show("Your Account resgistred Successfully", "information", MessageBoxButtons.OK, MessageBoxIcon.Information);
                        }
                        catch (Exception)
                        {
                            throw;
                        }
                        finally
                        {
                            Con.Close();
                        }
                    }
               } 
          }
     }
 }

输出：

确认用户名密码
1你好123 123
2你好123 123