設計思想：先通過之前的程式輸出四則運算的式子

                  再計算出正確答案

                  然後再輸入答案

                  最後比較輸入的答案與正確答案進行判斷對錯

日誌：

程式碼：

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;
using System.IO;

namespace 線上答題
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        
 
private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

        }

        public  void button1_Click(object sender, EventArgs e)
        {
            dataGridView1.DataSource = null;
            double n = Convert.ToDouble(textBox3.Text);
            double
 
 m = Convert.ToDouble(textBox2.Text);
            double num = Convert.ToDouble(textBox1.Text);
            double[] a = new double[2* (int)num];
            double[] tureans = new double[(int)num];
            dataGridView1.RowCount = (int)num;
            Random r = new Random();
            for (int i = 0; i < 2 * num; i++)
            {
                double temp = r.Next((int)m, (int)n);
                a[i] = temp;
            }
            string sign = "+";
            for(int i=0;i<num ;i++)
            {
                double  sum=a[i]+a[i+(int)num];
                if (a[i] % a[i + (int)num] == 0&&a[i + (int)num]!=0)
                {
                    sign = "/";
                    tureans[i] = a[i] / a[i + (int)num];
                }
                else if (sum <= (int)n / 2)
                {
                    sign = "*";
                    tureans[i] = a[i] * a[i + (int)num];
                }
                else if (a[i] > a[i + (int)num])
                {
                    sign = "-";
                    tureans[i] = a[i] - a[i + (int)num];
                }
                else
                {
                    sign = "+";
                    tureans[i] = a[i] + a[i + (int)num];
                }
                dataGridView1.Rows[i].Cells[0].Value = Convert.ToString(a[i]) + sign + Convert.ToString(a[i+(int)num])+"=";
                dataGridView1.Rows[i].Cells[2].Value = Convert.ToString(tureans[i]);  
            }
        }
        public void button2_Click(object sender, EventArgs e)
        {
            string path = @"C:\Users\11134\Desktop\錯題本.txt";
            if (File.Exists(path))
            {
                File.Delete(path);
            }
            double num = Convert.ToDouble(textBox1.Text);
            dataGridView1.Columns[2].Visible = true;
            dataGridView1.Columns[3].Visible = true;
            string wrrong = "";
            for (int i = 0; i < num; i++)
            {
                if (Convert.ToDouble(dataGridView1.Rows[i].Cells[1].Value) == Convert.ToDouble(dataGridView1.Rows[i].Cells[2].Value))
                {
                    dataGridView1.Rows[i].Cells[3].Value = "對";
                }
                else if (Convert.ToDouble(dataGridView1.Rows[i].Cells[1].Value) != Convert.ToDouble(dataGridView1.Rows[i].Cells[2].Value))
                {
                    dataGridView1.Rows[i].Cells[3].Style.BackColor = Color.Red;
                    dataGridView1.Rows[i].Cells[3].Value = "錯";
                    wrrong += Convert.ToString(dataGridView1.Rows[i].Cells[0].Value + "\r\n");
                }
            }
            StreamWriter sw = new StreamWriter(path);
            sw.WriteLine(wrrong);
            sw.Close();
        }
        private void button3_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

    }
}

視窗設計截圖：

 運算結果截圖：

錯題本截圖：