If-Statement为登录按钮

Question

I'm new to Visual Studio 2010. I'm creating a login form and in the login form there is a combobox and a textbox. The items in combobox is the list of positions of the employees. Whenever a user click the login button there should be an if statement in the login button so that there are forms will open in a specific position of the employees. Please help.

This is the screenshot:

This is the code:

private void loginbutton_Click(object sender, EventArgs e)
    {

        string MyConString = "SERVER=localhost;" + "DATABASE=timekeeping;" + "UID=root;" + "PASSWORD=admin;";
        MySqlConnection connection = new MySqlConnection(MyConString);
        MySqlCommand command = connection.CreateCommand();
        MySqlDataReader Reader;
        command.CommandText = "select username, password from users";
        connection.Open();
        Reader = command.ExecuteReader();
        while (Reader.Read())
        {
            if (username_login.Text == Reader[0].ToString() && password_login.Text == Reader[1].ToString().Trim())
            {
                username = Reader[0].ToString();
                password = Reader[1].ToString();
            }
        }

        if (username_login.Text == username && password_login.Text == password.Trim())
        {
            this.Hide();
            Home form = new Home();
            //form.userSession(lname, fname);
            form.Show();
        }
        else MessageBox.Show("Invalid User", "Login Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        connection.Close();
    }

I haven't included yet the combobox because I don't know what to put in here.

Answer 1

I think you need to reconsider your design:

It would be better if you stored the roles (position) of the users in the/a database.

If someone correctly identifies himself load the role(s) for that user and then open the correct form/application. Do not let the user select his role.

Have a look at the Membership and Role providers they're not just for ASP.NET, you can use them in Winforms as well:

Excellent set of tutorials:

• Part 1
• Part 2
• Part 3
• Part 4

Answer 2

How about something like the following:

        Form mainForm;

        switch (comboBox1.SelectedText)
        {
            case "Individual employees":
                mainForm = new EmployeesForm();
                break;
            case "HR":
                mainForm = new HRForm();
                break;
            case "Manager":
                mainForm = new ManagerForm();
                break;
            case "Supervisor":
                mainForm = new SupervisorForm();
                break;
            default:
                mainForm = new DefaultForm();
                break;
        }

        mainForm.Show();

This uses a conditional statement called the switch , which handles multiple selections by passing control to one of the case statements within its body.