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 Square.sln
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            DialogResult dr;    
            string i;           
            double num;         
            do
            {
                i = Microsoft.VisualBasic.Interation.InputBox
                    ("請輸入數值：", "求平方");
                num = Convert.ToDouble(i);     
                dr = MessageBox.Show(i + "的平方等於" + (num * num).ToString() +
                    "\n是否繼續?", "平方", MessageBoxButtons.YesNo);
            } while (dr == DialogResult.Yes);       
            Application.Exit();    
        }
    }
}

這裡紅線的Interation錯誤是指不要用還是不能用還是其他意思，只有查到避免名稱衝突這樣類似的答案，但還是不明白