Argthtjtr

NO asp.net c# used

I need to know if user is login once he/she enter a form and if he/she is not login, he goes back to the login form. Everywhere I saw people use asp.net to achieve that but I want to know how to do it without using asp.net.

public DataTable Login(String Username, String Password)
{

        server = "localhost";

        database = "xxxx";

        uid = "root";

        password = "";



        string MySQLConnectionString = $"datasource=127.0.0.1;port = 3306; SERVER={server}; DATABASE={database}; USERNAME={uid}; PASSWORD={password};sslmode=none";



        MySqlConnection db_Conn = new MySqlConnection(MySQLConnectionString);



        MySqlCommand cmd = new MySqlCommand();



        db_Conn.ConnectionString = MySQLConnectionString;



        string username_txtfield = username_txtbox.Text;

        string pw_txtfield = password_txtbox.Text;



        try

        {



            db_Conn.Open();

            cmd.Connection = db_Conn;



            cmd.CommandText = "SELECT count(*),user_id,person_username,role_id FROM user_tb " +

                "WHERE person_username=@username " +

                "AND user_password=@password";



            cmd.Prepare();

            cmd.Parameters.AddWithValue("@username", username_txtfield);

            cmd.Parameters.AddWithValue("@password", pw_txtfield);



            MySqlDataReader dr = cmd.ExecuteReader();



            DataTable dt = new DataTable();

            dt.Load(dr);

            db_Conn.Close();



            return dt;

        }

        catch (Exception ex)

        {

            throw ex;

        }

    }

login btn in my login form

    private void button1_Click(object sender, EventArgs e)

    {

        //login();

        try

        {

            DataTable result = Login(username_txtbox.Text, password_txtbox.Text);

            if (result.Rows.Count == 1)

            {

                this.Hide();



                string role = result.Rows[0]["role_id"].ToString();





                switch (role)

                {

                    case "3":

                        MessageBox.Show("User login successfully!");

                        user_form_page();

                        break;



                    case "1":



                        MessageBox.Show("Admin login successfully!");

                        //this.Hide();

                        Admin_page admin_form = new Admin_page();

                        admin_form.ShowDialog();

                        this.Close();

                        break;

                }

            }

            else

            {

                MessageBox.Show("INVALID USERNAME OR PASSWORD");

            }

        }

        catch (Exception ex)

        {

            MessageBox.Show(ex.Message);

        }



    }

Of course the ASP.Net identity services is a mature way of doing such a task but if you want you can have your own method of authentication but, you will need to implement many things.

Many of the stuff you need is actually based on the scenario you are implementing but the most basic thing you need is a static user that will be used via your methods to see if the user is already logged in or not. For example you can have:

public static class Authentication

{

    public static User CurrentUser { get; private set; }



    public static bool Login(User user)

    {

        if(user == null)

            throw new ArgumentException("Invalid user","user");

        CurrentUser = user;

    }

}

This is just the most basic implementation of such a thing you can then check if CurrentUser is null or not and direct user to login page or show her the results.

As your requirements grow you will need to implement more stuff. A logout, a local or remote database for users, store currently logged in user in disk so that she doesn't need to login again after closing the app and many other things

Edit

Based on your new information you can add this line to your login button click like this:

if (result.Rows.Count == 1)

{

    Authentication.Login(new User(result.Rows[0]["username"],result.Rows[0]["role_id"])

    //The rest of code

}

I have also presumed that you have a class like:

class User

{

    public string Name { get; }

    public int RoleId { get; }



    public User(string name, int roleId)

    {

        Name = name;

        RoleId = roleId;

    }

}

And then you have to check Authentication.CurrentUser against null in your user form or admin form constructors to ensure user is login you can use the information in Authentication.CurrentUser to show logged in user name or role or any other info.

I hope this helps you. If you need more info please say so.