CodingSandbox/UserPermissionTest_CS_WinForms/LoginDialog.cs

using System;
using System.Windows.Forms;

namespace UserPermissionTest_CS_WinForms
{
    public partial class LoginDialog : Form
    {
        public LoginDialog()
        {
            InitializeComponent();
        }

        private void btnLogin_Click(object sender, EventArgs e)
        {
            lblError.Visible = false;
            string username = txtUsername.Text.Trim();
            string password = txtPassword.Text;

            if (string.IsNullOrEmpty(username) || string.IsNullOrEmpty(password))
            {
                lblError.Text = "Please fill in all fields.";
                lblError.Visible = true;
                return;
            }

            if (SessionManager.Login(username, password))
            {
                this.DialogResult = DialogResult.OK;
                this.Close();
            }
            else
            {
                lblError.Text = "Invalid username or password!";
                lblError.Visible = true;
                txtPassword.Clear();
                txtPassword.Focus();
            }
        }

        private void btnCancel_Click(object sender, EventArgs e)
        {
            this.DialogResult = DialogResult.Cancel;
            this.Close();
        }

        private void btnTogglePassword_Click(object sender, EventArgs e)
        {
            if (txtPassword.PasswordChar == '•')
            {
                txtPassword.PasswordChar = '\0'; // Show password
                btnTogglePassword.Text = "🙈";
            }
            else
            {
                txtPassword.PasswordChar = '•'; // Mask password
                btnTogglePassword.Text = "👁";
            }
        }
    }
}