实现页面布局和数值初始化

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 WindowsFormsAppCalculator
{
    public partial class Form1 : Form
    {
        double number = 0;
        public Form1()
        {
            InitializeComponent();
        }


        private void num1_Click(object sender, EventArgs e)
        {
            number = number * 10 + 1;
            labelout.Text = Convert.ToString(number);
        }

        private void num2_Click(object sender, EventArgs e)
        {
            number = number * 10 + 2;
            labelout.Text = Convert.ToString(number);
        }

        private void num3_Click(object sender, EventArgs e)
        {
            number = number * 10 + 3;
            labelout.Text = Convert.ToString(number);
        }
        private void num4_Click(object sender, EventArgs e)
        {
            number = number * 10 + 4;
            labelout.Text = Convert.ToString(number);
        }

        private void num5_Click(object sender, EventArgs e)
        {
            number = number * 10 + 5;
            labelout.Text = Convert.ToString(number);
        }

        private void num6_Click(object sender, EventArgs e)
        {
            number = number * 10 + 6;
            labelout.Text = Convert.ToString(number);
        }

        private void num7_Click(object sender, EventArgs e)
        {
            number = number * 10 + 7;
            labelout.Text = Convert.ToString(number);
        }

        private void num8_Click(object sender, EventArgs e)
        {
            number = number * 10 + 8;
            labelout.Text = Convert.ToString(number);
        }

        private void num9_Click(object sender, EventArgs e)
        {
            number = number * 10 + 9;
            labelout.Text = Convert.ToString(number);
        }

        private void num0_Click(object sender, EventArgs e)
        {
            number = number * 10 + 0;
            labelout.Text = Convert.ToString(number);
        }


        private void Form1_Load(object sender, EventArgs e)
        {
            labelout.Text = Convert.ToString(number);
        }

        private void clean_Click(object sender, EventArgs e)
        {
            number = 0;
            labelout.Text = Convert.ToString(number);
        }
    }
}