作业要求：实训2：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 WindowsFormsApplication3

{

public partial class Form1 : Form

{

    public Form1()

    {

        InitializeComponent();

    }

    private void button1_Click(object sender, EventArgs e)

    {

        float num1 = 0;

        float num2 = 0;

        float result = 0;

        num1 = float.Parse(textBox1.Text);    //将文本框输入的字符转换成数值

        num2 = float.Parse(textBox2.Text);

        result = num1 * num2;

        textBox3.Text = result.ToString();  //将数值转换成字符

    }

    private void button2_click (object sender, EventArgs e)

    {

        textBox1.Text = "";

        textBox2.Text = "";

        textBox3.Text = "";

    }

}

}

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