C#—实验8.8和实验8.9

叁歲伎倆 2022-07-24 12:01 273阅读 0赞

/*
     * 利用Random类产生10个[10,99]之间的随机数，并将这10个随机数在列表框中显示出来，每个数占一项。
     * 用户选择某项后，在右边标签中显示所选内容。
     */
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    
    namespace WindowsFormsApplication2
    {
        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }
    
            private void Form1_Load(object sender, EventArgs e)
            {
                button1.Text = "结束";
                
                string[] s = new string[10];
                Random r = new Random();
                for (int i = 0; i < 10; i++)
                    s[i] = r.Next(10, 99).ToString();
                listBox1.Items.AddRange(s);
                listBox1.SelectedIndex = 0;
            }
    
            private void button1_Click(object sender, EventArgs e)
            {
                Application.Exit();
            }
    
            private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
            {
                label1.Text = listBox1.SelectedItem.ToString();
            }
        }
    }

运行结果：

![Center][]

/*
     * （1）控件依次是：文本框、组合框、文本框、标签、文本框和按钮；
     * （2）各个控件名字默认；
     * （3）组合框Items属性中加入+、-、*、/，且DropDownList。
     */
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    
    namespace WindowsFormsApplication1
    {
        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }
    
            private void Form1_Load(object sender, EventArgs e)
            {
                button1.Text = "选择不同运算符，单击按钮进行不同运算";
                label1.Text = "=";
                string []s=new string[4]{"+","-","*","/"};
                comboBox1.Items.AddRange(s);
            }
    
            private void button1_Click(object sender, EventArgs e)
            {
                switch (comboBox1.Text)
                {
                    case "+":
                        textBox3.Text=(Convert.ToDouble(textBox1.Text)+Convert.ToDouble(textBox2.Text)).ToString();
                        break;
                    case "-":
                        textBox3.Text=(Convert.ToDouble(textBox1.Text)-Convert.ToDouble(textBox2.Text)).ToString();
                        break;
                    case "*":
                        textBox3.Text=(Convert.ToDouble(textBox1.Text)*Convert.ToDouble(textBox2.Text)).ToString();
                        break;
                    case "/":
                        textBox3.Text =(Convert.ToDouble(textBox1.Text)/Convert.ToDouble(textBox2.Text)).ToString();
                        break;
                }
            }
        }
    }

运行结果：

![Center 1][]

[Center]: /images/20220722/28b3b77e0512442794563da72bd80550.png
[Center 1]: /images/20220722/e1f0a720cb264693a35c78427f57b09e.png