Question

下面的代码有什么问题？我的代码给我一些错误。我想在我们的项目上使用面向对象的程序，但是它不能正常工作。有人可以帮我解决我的问题

 class Login
    {
        public string Username { get; set; }
        public string Userpassword { get; set; }

        public Login()
        {
            this.Username = user; //does not exist in the current context
            this.Userpassword = pass; //does not exist in the current context
        }

        private void ClearTexts(string user, string pass)
        {
            user = String.Empty;
            pass = String.Empty;
        }

        public void Login(string user, string pass)
        {
            int count = 0;
            Connection connection = new Connection();
            string sql = "SELECT * FROM tbl_Login";
            MySqlConnection conn = new MySqlConnection(connection.ConnectionString);
            MySqlCommand cmd = new MySqlCommand(sql, conn);
            conn.Open();
            MySqlDataReader dr = cmd.ExecuteReader();

            while (dr.Read())
            {
                count = count + 1;

            }
            if (count == 1)
            {
                MessageBox.Show("Login Successfully!");
                frmLogin.Hide(); //required for the non-static field,method
                frmMain.showMe(this); //best overloaded method match...
            }
            else
            {
                txtPassword.Focus(); /does not exist in the current context
                MessageBox.Show("Username or Password Is Incorrect");
                txtUserName.Text = ""; //does not exist in the current context
                txtPassword.Text = ""; //does not exist in the current context

            }
            connection.Close();
        }
    }

Answer 1

您不需要没有参数的create class client extends v构造函数。而是使用以下参数将字段设置下移至构造函数：

Login()

Answer 2

public Login(){
 this.Username = user; //does not exist in the current context
 this.Userpassword = pass; //does not exist in the current context
}

user和pass不是函数的参数，因此它们不存在。您已经有一个接受用户并通过的构造函数，因此此函数应将其设置为null或不存在，并强制使用user / pass构造函数

如何制作面向对象的登录程序？

2 个答案: