C#實驗課：人民幣和美元兌換

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.Windows.Forms;

namespace bt
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
private void label1_Click(object sender, EventArgs e)//標籤1，用於顯示人民幣
        {


        }
private void label2_Click(object sender, EventArgs e)//標籤2，用於顯示匯率
        {


        }

private void label3_Click(objectsender,EventArgs e) //標籤3，用於顯示美元

        {

        }
private void textBox1_TextChanged(objectsender, EventArgs e)//文本框1，用於輸入人民幣
        {

        }
private void textBox2_TextChanged(object sender, EventArgs e) //文本框2，用於輸入匯率
        {

        }
private void textBox3_TextChanged(object sender, EventArgs e) //文本框3，用於輸入美元
        {

        }
private void b1_Click(object sender,EventArgs e) //按鈕1清屏函數。
    {
     t1.Text = ""; 
    t2.Text = "";
     t3.Text = ""; 
     }
private void b2_Click(object sender,EventArgs 
e) //按鈕2￥-$轉換 
    { t3.Text=Convert.ToString(Convert.ToDouble(t1.Text) / Convert.ToDouble(t2.Text));
     } 

private void b3_Click(objectsender,EventArgse) //按鈕3$-￥轉換
    {
t1.Text=Convert.ToString(Convert.ToDouble(t3.Text) * Convert.ToDouble(t2.Text)); 
    }

 private void b4_Click(objectsender,EventArgs e) //退出按鈕 
        { 
        Application.Exit(); 
        } 
    }
}