亂數不重複
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 WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        int rndmoney1 = 0;
        int rndmoney2 = 0;
        int rndmoney3 = 0;
        int rndmoney4 = 0;
        int rndmoney5 = 0;
        int rndmoney6 = 0;
        int rndmoney7 = 0;
        int rndmoney8 = 0;
        int rndmoney9 = 0;
        public Form1()
        {
            InitializeComponent();
            button1.Enabled = false;
            button2.Enabled = false;
            button3.Enabled = false;
            button4.Enabled = false;
            button5.Enabled = false;
            button6.Enabled = false;
            button7.Enabled = false;
            button8.Enabled = false;
            button9.Enabled = false;
        }

        private void button10_Click(object sender, EventArgs e)
        {
            Random rnd = new Random();
            rndmoney1 = rnd.Next(0, 9); // creates a number between 1 and 9

            rndmoney2 = rnd.Next(0, 9); // creates a number between 1 and 9
            //rndmoney3 = rnd.Next(0, 9); // creates a number between 1 and 9
            //rndmoney4 = rnd.Next(0, 10); // creates a number between 1 and 9
            //rndmoney5 = rnd.Next(0, 10); // creates a number between 1 and 9
            //rndmoney6 = rnd.Next(0, 10); // creates a number between 1 and 9
            //rndmoney7 = rnd.Next(0, 10); // creates a number between 1 and 9
            //rndmoney8 = rnd.Next(0, 10); // creates a number between 1 and 9
            //rndmoney9 = rnd.Next(0, 10); // creates a number between 1 and 9
            button1.Text = rndmoney1.ToString();
            button2.Text = rndmoney2.ToString();
            if (rndmoney1 == rndmoney2)
            {
                MessageBox.Show("Dot Net Perls is awesome.");
                rndmoney2 = rnd.Next(0, 9); // creates a number between 1 and 9
                button2.Text = rndmoney2.ToString();
            }
            //button3.Text = rndmoney3.ToString();
            //button4.Text = rndmoney4.ToString();
            //button5.Text = rndmoney5.ToString();
            //button6.Text = rndmoney6.ToString();
            //button7.Text = rndmoney7.ToString();
            //button8.Text = rndmoney8.ToString();
            //button9.Text = rndmoney9.ToString();
            //button10.Enabled = false;
        }
    }
}