第三节 3练习1 简单

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 _3练习1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string str_width = tb_width.Text;
            string str_height = tb_height.Text;
            //判断值是否有效
            int i1, i2, sum;
            if (!int.TryParse(str_width, out i1)) {
                MessageBox.Show("宽为非整数!");
                return;
            }
            if (!int.TryParse(str_height, out i2)) {
                MessageBox.Show("高为非整数!");
                return;
            }
            sum = i1 * i2;
            tb_sum.Text = Convert.ToString(sum);


        }

        private void button2_Click(object sender, EventArgs e)
        {
            string email = tb_email.Text;
            //进行字符串进行分析,然后放入数组中的
            //这里用数组的长度来判断该email是否有效
            string[] str = email.Split('@');
            if (str.Length != 2) {
                MessageBox.Show("Email不合法!");
                return;
            }

            tb_name.Text = str[0];
            tb_www.Text = str[1]; 
        }

        private void button3_Click(object sender, EventArgs e)
        {
            //求累加
            string str1 = tb_start.Text;
            string str2 = tb_end.Text;
            int i1, i2;
            if (!int.TryParse(str1, out i1)){
                MessageBox.Show("第一个数值不是整数!");
                return;
            }
            if (!int.TryParse(str2, out i2)) {
                MessageBox.Show("第二个数值不是整数!");
                return;
            }
            if (i2 <= i1) {
                MessageBox.Show("第二个值不能小大第一个值!");
                return;
            }
            int sum = 0;
            for (int i = i1; i <= i2; i++) {
                sum += i;
            }
            tb_count.Text = Convert.ToString(sum);
        }


    }
}