C#实现简单计算器功能

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 Cal{  public partial class Form1 : Form  {    public double num1;    public int temp = 0;//记录存储计算方式    public Form1()    {      InitializeComponent();    }        private void eq_Click(object sender, EventArgs e)    {      switch (temp)      {        //加法运算        case 1:          try          {            result.Text = (num1 + double.Parse(result.Text)).ToString();          }          catch (Exception)          {            MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);          }          finally          {            temp = 0;          }          break;        //减法运算        case 2:          try          {            result.Text = (num1 - double.Parse(result.Text)).ToString();          }          catch (Exception)          {            MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);          }          finally          {            temp = 0;          }          break;        //乘法运算        case 3:          try          {            result.Text = (num1 * double.Parse(result.Text)).ToString();          }          catch (Exception)          {            MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);          }          finally          {            temp = 0;          }          break;        //除法运算，讨论分母为零的情况        case 4:          if (double.Parse(result.Text)==0)          {            MessageBox.Show("除数不能为零", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);            result.ResetText();          }          else          {            result.Text = (num1 / double.Parse(result.Text)).ToString(); temp = 0;          }          break;        case 5:          try          {            result.Text = (num1 % double.Parse(result.Text)).ToString();          }          catch (Exception)          {            MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);          }          finally          {            temp = 0;          }          break;      }    }    private void empty_Click(object sender, EventArgs e)    {      result.Text = "0";      num1 = 0;      temp = 0;      //清除      //if (result.Text.Length > 0)      //{      //  result.Text = result.Text.Substring(0, result.Text.Length - 1);      //}    }    private void Zero_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "0";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "0";      }    }    private void one_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "1";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "1";      }    }    private void two_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "2";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "2";      }    }    private void three_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "3";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "3";      }    }    private void four_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "4";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "4";      }    }    private void five_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "5";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "5";      }    }    private void six_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "6";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "6";      }    }    private void seven_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "7";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "7";      }    }    private void eight_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "8";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "8";      }    }    private void nine_Click(object sender, EventArgs e)    {      if (result.Text == "0")      {        result.Text = "9";      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + "9";      }    }    private void point_Click(object sender, EventArgs e)    {      //小数点按键，初始为空，直接按 . 键则显示为0.多少      if (result.Text == "")      {        result.Text = "0.";      }      //如果再次输入.则返回都输入的字符后边并提示信息      else if (result.Text.IndexOf(".") >= 0)      {        MessageBox.Show("已经输入小数点,无须再次输入", "提示");      }      else      {        //前边有数字时，则直接在后边加上.        result.Text = result.Text + ".";      }    }    private void add_Click(object sender, EventArgs e)    {      temp = 1;      try      {        num1 = double.Parse(result.Text);      }      catch (Exception)      {        MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);      }      finally      {        result.Text = "";//随后让文本框归空      }    }    private void mul_Click(object sender, EventArgs e)    {      temp = 3;      try      {        num1 = double.Parse(result.Text);      }      catch (Exception)      {        MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);      }      finally      {        result.Text = "";//随后让文本框归空      }    }    private void sub_Click(object sender, EventArgs e)    {      temp = 2;      try      {        num1 = double.Parse(result.Text);      }      catch(Exception)      {        MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);      }      finally      {       result.Text = "";//随后让文本框归空      }    }    private void Button1_Click(object sender, EventArgs e)    {      temp = 4;      try      {        num1 = double.Parse(result.Text);      }      catch (Exception)      {        MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);      }      finally      {        result.Text = "";//随后让文本框归空      }    }    private void per_Click(object sender, EventArgs e)    {      temp = 5;      try      {        num1 = double.Parse(result.Text);      }      catch (Exception)      {        MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);      }      finally      {        result.Text = "";//随后让文本框归空      }    }    private void opp_Click(object sender, EventArgs e)    {      //temp = 6;      try        {         result.Text = (-double.Parse(result.Text)).ToString();        }      catch (Exception)        {          MessageBox.Show("还没输入数字呢", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);        }      finally          {        temp = 0;          }    }        private void Form1_Load(object sender, EventArgs e)    {      result.Text = "0";    }    private void result_TextChanged(object sender, EventArgs e)    {      if (result.Text.Length > 18&& result.Text.Length<36)      {        result.Font = new Font(result.Font.FontFamily, 15, result.Font.Style);      }      if (result.Text.Length > 36&&result.Text.Length<45)      {        result.Font = new Font(result.Font.FontFamily, 10, result.Font.Style);      }      if (result.Text.Length > 45)      {        MessageBox.Show("超出范围，将要清空了！", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);        result.ResetText();        result.Font = new Font(result.Font.FontFamily, 20, result.Font.Style);      }    }  }}