c#银行本息和计算器

先看运行结果：

控件好摆，主要代码如下：

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

        private void button1_Click(object sender, EventArgs e) //当用户点击时显示计算结果
        {
            try
            {
                string str01 = this.principal.Text.Trim();
                string str02 = this.rate.Text.Trim();
                string str03 = this.loanPeriod.Text.Trim();

                double p = Convert.ToDouble(str01);
                double r = Convert.ToDouble(str02) / 100;
                double t = Convert.ToDouble(str03);

                if (this.simple.Checked)
                {
                    //单利计算公式
                    this.totalAmount.Text = Convert.ToString(p + p * r * t);
                }
                if (this.compound.Checked)
                {
                    //复利计算公式
                    this.totalAmount.Text = Convert.ToString(p * Math.Pow(1 + r, t));
                }
            }
            catch
            {
                MessageBox.Show("输入为空或非法字符，请重新输入！","错误");
            }
            
        }

        private void simple_CheckedChanged(object sender, EventArgs e)
        {
            try
            {
                string str01 = this.principal.Text.Trim();
                string str02 = this.rate.Text.Trim();
                string str03 = this.loanPeriod.Text.Trim();

                double p = Convert.ToDouble(str01);
                double r = Convert.ToDouble(str02) / 100;
                double t = Convert.ToDouble(str03);

                if (this.simple.Checked)
                {
                    this.totalAmount.Text = Convert.ToString(p + p * r * t);
                }
                if (this.compound.Checked)
                {
                    this.totalAmount.Text = Convert.ToString(p * Math.Pow(1 + r, t));
                }
            }
            catch
            {
                MessageBox.Show("输入为空或非法字符，请重新输入！","错误");
            }
            
        }

        private void button2_Click(object sender, EventArgs e)  //点击使所有文本框清空且默认选择简单计算方式
        {
            this.simple.Checked = true;
            this.compound.Checked = false;
            this.principal.Text = null;
            this.rate.Text = null;
            this.loanPeriod.Text = null;
            this.totalAmount.Text = null;
        }

        private void button3_Click(object sender, EventArgs e)  
        //使程序退出
        {
            Application.Exit();
        }
    }
}

早期写的代码，习惯还不太好…………见谅啊大佬们！