• 使用 switch 語句判斷分?jǐn)?shù)區(qū)間

代碼

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp3
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("請(qǐng)輸入等級(jí): ");
            char level = (char)Console.Read();
            switch(char.ToUpper(level))
            {
                case 'A':
                    {
                        Console.WriteLine($"{level} 是90-100");
                        break;
                    }
                case 'B':
                    {
                        Console.WriteLine($"{level} 是80-90");
                        break;
                    }
                case 'C':
                    {
                        Console.WriteLine($"{level} 是60-80");
                        break;
                    }
                case 'D':
                    {
                        Console.WriteLine($"{level} 是不及格");
                        break;
                    }
            }
        }
    }
}

輸出

捕獲.PNG

• 角谷猜想

代碼

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp4
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("請(qǐng)輸入一個(gè)整數(shù): ");
            string n = Console.ReadLine();
            int num = Convert.ToInt32(n);

            int a = num;
            int count = 0;
            while(a!=1)
            {
                Console.Write($"{a}\t");
                count++;
                if(count%5==0)
                {
                    Console.WriteLine();
                }
                if(a%2==1)
                {
                    a = 3 * a + 1;
                }
                else
                {
                    a = a / 2;
                }
            }
            Console.Write($"{a}\t");
        }
    }
}

輸出

捕獲2.PNG

• 畫很多圓

代碼

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;

namespace WindowsFormsApp5
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        Random random = new Random();

        Color getRandomColor()
        {
            return Color.FromArgb(
                random.Next(256),
                random.Next(256),
                random.Next(256));
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();

            int x0 = this.Width / 2;
            int y0 = this.Height / 2;

            for(int r=0;r<y0/2;r++)
            {
                g.DrawEllipse(new Pen(getRandomColor(), 1),
                    x0 - r, y0 - r, r * 2, r * 2);
            }
            g.Dispose();
        }
    }
}

在設(shè)計(jì)界面只要添加一個(gè) button

輸出

捕獲.PNG