programminoditthoonee

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace loginform
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void label2_Click(object sender, EventArgs e)
        {
                   }

        private void button1_Click(object sender, EventArgs e)
        {
            string a;
            char lett;
            bool maiusc=false;
            bool num = false;
            bool minusc=false;
            a = pasw.Text;

            if(a.Length<8)
                MessageBox.Show("troppo corto");

            for (int i = 0; i < a.Length; i++)
            {
                //lett = Convert.ToChar(a.Substring(i, 1));
                lett= a.ElementAt(i);
                if (lett >= 'A' && lett <= 'Z')
                    maiusc = true;
                if (lett > 'a' && lett <= 'z')
                    minusc = true;
                if (lett >= '0' && lett <= '9')
                    num = true;
            }
            if (maiusc == true && minusc == true && num == true)
                MessageBox.Show("valida");
            if (maiusc == false && minusc == true && num == true)
            {
                lblcontrol.Visible = true;
                lblcontrol.ForeColor = Color.Red;
                lblcontrol.Text = "manca la maiuscola";


            }
            if (maiusc == true && minusc == false && num == true)
            {
                lblcontrol.Visible = true;
                lblcontrol.ForeColor = Color.Red;
                lblcontrol.Text = "manca la minuscola";


            }
            if (maiusc == true && minusc == true && num == false)
            {
                lblcontrol.Visible = true;
                lblcontrol.ForeColor = Color.Red;
                lblcontrol.Text = "manca il numero";


            }
            if (maiusc == false && minusc == false && num == true)
            {
                lblcontrol.Visible = true;
                lblcontrol.ForeColor = Color.Red;
                lblcontrol.Text = "manca la maiuscola e la minuscola";


            }
            if (maiusc == false && minusc == true && num == false)
            {
                lblcontrol.Visible = true;
                lblcontrol.ForeColor = Color.Red;
                lblcontrol.Text = "manca la maiuscola e il numero";


            }
            if (maiusc == true && minusc == false && num == false)
            {
                lblcontrol.Visible = true;
                lblcontrol.ForeColor = Color.Red;
                lblcontrol.Text = "manca la minuscola e il numero";


            }
        }
    }
}