I am fairly new to coding in C# and using windows forms applications and SQLite for databases, and I was wondering if there way that I can keep a user logged in and display said user's ID on different forms to show that they are logged in. The project itself is an ordering system and I wish for a customer to login to perform any purchases so that it can be logged as part of a management report. The code is below if it is of any help.

        int charlengthusername= usernametextbox.Text.Length;
        int charlengthpassword = passwordtextbox.Text.Length;
        if (charlengthusername <= 4 || charlengthusername >= 6 || charlengthpassword >=13||String.IsNullOrEmpty(usernametextbox.Text)||String.IsNullOrEmpty(passwordtextbox.Text))
        {
            MessageBox.Show("Details Entered Don't Meet The Expected Character Length Requirements. Try Again.");
            usernametextbox.Clear();
            passwordtextbox.Clear();
        }
        //make another if for user and pass matching  
        //change else below to be inside of username and password match if statement so that it will only send to custmainmenu when username and password has been matched
        else
        {
            sqlite_conn = new SQLiteConnection("Data Source=CustomerDatabase.db; Version = 3; New = True; Compress = True;");
            sqlite_conn.Open();
            SQLiteDataReader sqlite_datareader;
            string user = usernametextbox.Text;
            string pass = passwordtextbox.Text;
            sqlite_cmd = sqlite_conn.CreateCommand();
            sqlite_cmd.Connection = sqlite_conn;
            sqlite_cmd.CommandText = "SELECT * FROM TblCustomer where CustRandID='"   usernametextbox.Text   "' AND CustPassword='"   passwordtextbox.Text   "'";
            sqlite_datareader = sqlite_cmd.ExecuteReader();
            if (sqlite_datareader.Read())
            {

                MessageBox.Show("Login Successful! ");
                this.Hide();
                var openmainmenu = new CustomerMainMenu();
                openmainmenu.Closed  = (t, args) => this.Close();
                openmainmenu.Show();
            }
            else
            {
                MessageBox.Show("Incorrct Details! Try Again! ");
                this.Hide();
                var spenmainmenu = new CustomerLogin();
                spenmainmenu.Closed  = (s, args) => this.Close();
                spenmainmenu.Show();
            }
            sqlite_conn.Close();
        }
    }

CodePudding user response：

The simplest approach would be to just store the validated username/password in a public static property in a static class.

public static class AppInfo {
  public static string Username = "";
}

// ...

MessageBox.Show("Login Successful! ");
AppInfo.Username = user;

You can then access that Username (and any other global data your app might need) from AppInfo (which you could name something else, of course).

CodePudding user response：

You can use static members in a class and reach them from any form.

   class UserInfo {
        public static String UserName  ="";
        public static bool IsLoggedIn  = false;
    }

You need to set values inside of login successful block like that:

UserInfo.IsLoggedIn = true;
UserInfo.UserName = "Uday Patel";