基于C#桌面应用制作计算器做出了少量改动，其主要改动为新增加了一个label控件，使其每一步运算结果由label2展示出来，而当点击“=”时，最终运算结果将由label1展示出来，此时label清空。
修改后运行效果
修改后全篇代码
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 WindowsFormsApp计算器
{
public partial class Form1 : Form
{
string symbol, num1, num2,Num1,Num2;
double rt;
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
label1.Text = null;
label2.Text = null;
num1=null;
num2=null;
symbol = null;
}
private void button2_Click(object sender, EventArgs e)
{
if (label1.Text.Length == 0&&symbol==null)
{
label1.Text = null;
}else if (label1.Text.Length == 0 && symbol != null)
{
label1.Text = symbol;
}
else
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = num1;
symbol = null;
}
else
{
string del = label1.Text;
label1.Text = del.Substring(0, del.Length - 1);
label2.Text = label1.Text;
if (label2.Text.Length>0&& label1.Text.Length != 0)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
else
{
if (label1.Text.Length <= 1 && symbol == null)
{
label2.Text=null;
}
else
{
label2.Text = num1;
}
}
if (label1.Text.Length < 30)
{
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
}
}
}
private void button3_Click(object sender, EventArgs e)
{
if (label1.Text.Length == 0)
{
MessageBox.Show("error");
}
else if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
MessageBox.Show("error");
}
else
{
double reserve = double.Parse(label1.Text);
reserve = -reserve;
label1.Text = reserve.ToString();
if (num1 != null && symbol != null)
{
num2 = reserve.ToString();
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
}
private void button4_Click(object sender, EventArgs e)
{
string divide = "÷";
if (symbol == null && label1.Text.Length<1&&num1==null)
{
MessageBox.Show("无运算数字");
}
else
{
if (symbol == null)
{
if(num1 == null)
{
num1 = label1.Text;
}
symbol = divide;
label1.Text = symbol;
label2.Text = num1;
}
else
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷") {
MessageBox.Show("您已输入运算符");
}
else
{
num2 = label1.Text;
num1 = rt.ToString();
symbol = divide;
label1.Text = symbol;
label2.Text = rt.ToString();
num2 = null;
}
}
}
}
private void button8_Click(object sender, EventArgs e)
{
string seven = "7";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;//如果前面有运算符，则先消除运算符再把数字投射到屏幕上
}
label1.Text = label1.Text + seven;//将数字投射到屏幕上
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if(num1!=null&&symbol!=null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button7_Click(object sender, EventArgs e)
{
string eight = "8";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;
}
label1.Text = label1.Text + eight;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if (num1 != null && symbol != null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button6_Click(object sender, EventArgs e)
{
string nine = "9";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;
}
label1.Text = label1.Text + nine;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if (num1 != null && symbol != null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button5_Click(object sender, EventArgs e)
{
string multiply = "×";
if (symbol == null && label1.Text.Length < 1 && num1 == null)
{
MessageBox.Show("无运算数字");
}
else
{
if (symbol == null)
{
if (num1 == null)
{
num1 = label1.Text;
}
symbol = multiply;
label1.Text = symbol;
label2.Text = num1;
}
else
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
MessageBox.Show("您已输入运算符");
}
else
{
num2 = label1.Text;
num1 = rt.ToString();
symbol = multiply;
label1.Text = symbol;
label2.Text = rt.ToString();
num2 = null;
}
}
}
}
private void button12_Click(object sender, EventArgs e)
{
string four = "4";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;
}
label1.Text = label1.Text + four;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if (num1 != null && symbol != null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button11_Click(object sender, EventArgs e)
{
string five = "5";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;
}
label1.Text = label1.Text + five;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if (num1 != null && symbol != null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button10_Click(object sender, EventArgs e)
{
string six = "6";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;
}
label1.Text = label1.Text + six;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if (num1 != null && symbol != null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button9_Click(object sender, EventArgs e)
{
string subtract = "-";
if (symbol == null && label1.Text.Length < 1 && num1 == null)
{
MessageBox.Show("无运算数字");
}
else
{
if (symbol == null)
{
if (num1 == null)
{
num1 = label1.Text;
}
symbol = subtract;
label1.Text = symbol;
label2.Text = num1;
}
else
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
MessageBox.Show("您已输入运算符");
}
else
{
num2 = label1.Text;
num1 = rt.ToString();
symbol = subtract;
label1.Text = symbol;
label2.Text = rt.ToString();
num2 = null;
}
}
}
}
private void button16_Click(object sender, EventArgs e)
{
string one = "1";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;
}
label1.Text = label1.Text + one;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if (num1 != null && symbol != null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button15_Click(object sender, EventArgs e)
{
string two = "2";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;
}
label1.Text = label1.Text + two;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if (num1 != null && symbol != null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button14_Click(object sender, EventArgs e)
{
string three = "3";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;
}
label1.Text = label1.Text + three;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if (num1 != null && symbol != null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button13_Click(object sender, EventArgs e)
{
string add = "+";
if (symbol == null && label1.Text.Length < 1 && num1 == null)
{
MessageBox.Show("无运算数字");
}
else
{
if (symbol == null)
{
if (num1 == null)
{
num1 = label1.Text;
}
symbol = add;
label1.Text = symbol;
label2.Text = num1;
}
else
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
MessageBox.Show("您已输入运算符");
}
else
{
num2 = label1.Text;
num1 = rt.ToString();
symbol = add;
label1.Text = symbol;
label2.Text = rt.ToString();
num2 = null;
}
}
}
}
private void label2_Click(object sender, EventArgs e)
{
}
private void label1_Click(object sender, EventArgs e)
{
}
private void button20_Click(object sender, EventArgs e)
{
if (label1.Text.Length == 0)
{
MessageBox.Show("error");
}
else if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
MessageBox.Show("error");
}
else
{
double reserve = double.Parse(label1.Text);
reserve = reserve / 100;
label1.Text = reserve.ToString();
if (num1 != null && symbol != null)
{
num2 = reserve.ToString();
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
}
private void button19_Click(object sender, EventArgs e)
{
string zero = "0";
if (label1.Text.Length < 30)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
label1.Text = null;
}
label1.Text = label1.Text + zero;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
if (num1 != null && symbol != null)
{
num2 = label1.Text;
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label2.Text = rt.ToString();
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label2.Text = rt.ToString();
}
}
}
private void button18_Click(object sender, EventArgs e)
{
string dot = ".";
int f=label1.Text.IndexOf(".");
if(f == -1)
{
if(label1.Text.Length == 0)
{
MessageBox.Show("error");
}
else if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
MessageBox.Show("error");
}
else
{
if (label1.Text.Length < 30)
{
label1.Text = label1.Text + dot;
if (label1.Text.Length > 16)
{
label1.Font = new Font(label1.Font.FontFamily, 13f, label1.Font.Style);
}
else
{
label1.Font = new Font(label1.Font.FontFamily, 26f, label1.Font.Style);
}
}
else
{
MessageBox.Show("字符长度超出范围");
}
}
}
else
{
MessageBox.Show("error");
}
}
private void button17_Click(object sender, EventArgs e)
{
if (symbol == null && label1.Text.Length < 1)
{
MessageBox.Show("无运算数字");
}
else
{
if (symbol == null)
{
num1 = label1.Text;
}
else
{
if (label1.Text != null)
{
if (label1.Text == "+" || label1.Text == "-" || label1.Text == "×" || label1.Text == "÷")
{
MessageBox.Show("error");
}
else
{
num2 = label1.Text;
}
}
}
}
if (num2 != null)
{
if (symbol == "+")
{
rt = double.Parse(num1) + double.Parse(num2);
label1.Text = rt.ToString();
label2.Text=null;
num1 = rt.ToString();
symbol = null;
num2 = null;
}
else if (symbol == "-")
{
rt = double.Parse(num1) - double.Parse(num2);
label1.Text = rt.ToString();
label2.Text=null;
num1 = rt.ToString();
symbol = null;
num2 = null;
}
else if (symbol == "×")
{
rt = double.Parse(num1) * double.Parse(num2);
label1.Text = rt.ToString();
label2.Text=null;
num1 = rt.ToString();
symbol = null;
num2 = null;
}
else if (symbol == "÷")
{
rt = double.Parse(num1) / double.Parse(num2);
label1.Text = rt.ToString();
label2.Text=null;
num1 = rt.ToString();
symbol = null;
num2 = null;
}
}
}
}
}