c#简易计算器

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 计算器
{
    public partial class Form6 : Form
    {
        public Form6()
        {
            InitializeComponent();
        }
        //上一个按钮是否是运算符；
        //一个面积为50的矩形  求他能形成圆的最大面积
        bool iscalc = false;
        //1
        private void button1_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                 textBox1.Text = "";
                 iscalc = false;
            }
            textBox1.Text += 1;
        }


        //2
        private void button2_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                textBox1.Text = "";
                iscalc = false;
            }
            textBox1.Text += 2;
        }
        //3
      
        private void button3_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                textBox1.Text = "";
                iscalc = false;
            }
            textBox1.Text += 3;
        }
        //4
        
        private void button4_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                textBox1.Text = "";
                iscalc = false;
            }
            textBox1.Text += 4;
        }
        //5
       
        private void button5_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                textBox1.Text = "";
                iscalc = false;
            }
            textBox1.Text += 5;
        }
        //6
       
        private void button6_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                textBox1.Text = "";
                iscalc = false;
            }
            textBox1.Text += 6;
        }
        //7
       
        private void button7_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                textBox1.Text = "";
                iscalc = false;
            }
            textBox1.Text += 7;
        }
        //8
       
        private void button8_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                textBox1.Text = "";
                iscalc = false;
            }
            textBox1.Text += 8;
        }
        //9
       
        private void button9_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                textBox1.Text = "";
                iscalc = false;
            }
            textBox1.Text += 9;
        }
        //0
       
        private void button10_Click_1(object sender, EventArgs e)
        {
            if (iscalc == true)
            {
                textBox1.Text = "";
                iscalc = false;//不改回false时会一直清除数字。
            }
            textBox1.Text += 0;
        }
        double num1;
        bool isdel = false;
        string yunsuan;
        double num2;
        //+
      
        private void button11_Click_1(object sender, EventArgs e)
        {
            yunsuan = "+";
            isdel = false;
            iscalc = true;

            if (double.TryParse(textBox1.Text, out num1))
            {
                num1 = double.Parse(textBox1.Text);
            }
            else
            {
                return;
            }
        }
        //-

      
        private void button12_Click_1(object sender, EventArgs e)
        {
            yunsuan = "-";
            isdel = false;
            iscalc = true;
            if (double.TryParse(textBox1.Text, out num1))
            {
                num1 = double.Parse(textBox1.Text);
            }
            else
            {
                return;
            }
        }
        //*
       
        private void button13_Click_1(object sender, EventArgs e)
        {
            yunsuan = "*";
            isdel = false;
            iscalc = true;
            if (double.TryParse(textBox1.Text, out num1))
            {
                num1 = double.Parse(textBox1.Text);
            }
            else
            {
                return;
            }
        }
        //÷
        
        private void button14_Click_1(object sender, EventArgs e)
        {
            yunsuan = "÷";
            isdel = false;
            iscalc = true;
            if (double.TryParse(textBox1.Text, out num1))
            {
                num1 = double.Parse(textBox1.Text);
            }
            else
            {
                return;
            }
        }
        //=
       
        private void button15_Click_1(object sender, EventArgs e)
        {
            if (double.TryParse(textBox1.Text, out num2))
            {
                num2 = double.Parse(textBox1.Text);
            }

            else
            {
                return;
            }

            iscalc = true;
            //num2 = double.Parse(textBox1.Text);
            if (yunsuan == "+")
            {
                textBox1.Text = (num1 + num2).ToString();
            }
            if (yunsuan == "-")
            {
                textBox1.Text = (num1 - num2).ToString();
            }
            if (yunsuan == "*")
            {
                textBox1.Text = (num1 * num2).ToString();
            }
            if (yunsuan == "÷")
            {
                textBox1.Text = (num1 / num2).ToString();
            }
            //textBox2.Text = 2*π * textBox2.Text;
        }
        //.
       
        private void button16_Click_1(object sender, EventArgs e)
        {
            if (isdel == false)
            {
                textBox1.Text += ".";
                isdel = true;
            }
        }
        //CE
      

        private void button17_Click_1(object sender, EventArgs e)
        {
            textBox1.Text = "";
            isdel = false;
        }
        //平方
        private void button18_Click(object sender, EventArgs e)
        {
            num1 = double.Parse(textBox1.Text);
            textBox1.Text = (Math.Pow(num1, 2)).ToString();
            iscalc = true;
        }
        //cos
        private void button19_Click(object sender, EventArgs e)
        {
            num1 = double.Parse(textBox1.Text);
            iscalc = true;
            textBox1.Text = (Math.Cos(num1)).ToString();
        }
        //tan
        private void button21_Click(object sender, EventArgs e)
        {
            num1 = double.Parse(textBox1.Text);
            iscalc = true;
            textBox1.Text = (Math.Tan(num1)).ToString();
        }
        //sin
        private void button20_Click(object sender, EventArgs e)
        {
            num1 = double.Parse(textBox1.Text);
            iscalc = true;
            textBox1.Text = (Math.Sin(num1)).ToString();
          
        }
        //Asin
        private void button22_Click(object sender, EventArgs e)
        {
            num1 = double.Parse(textBox1.Text);
            iscalc = true;
            textBox1.Text = (Math.Asin(num1)).ToString();
        }
        //圆的周长
        private void button23_Click(object sender, EventArgs e)
        {
            num1 = double.Parse(textBox2.Text);
            iscalc = true;
            textBox1.Text = (Math.PI*(num1*2)).ToString();
        }
        //圆的面积
        private void button24_Click(object sender, EventArgs e)
        {
            num1 = double.Parse(textBox2.Text);
            iscalc = true;
            textBox1.Text = (Math.PI*2*(num1*num1)).ToString();
            
        }
        //  v^2=2gs;  小球100米处掉落求掉落时大概速度
        private void button25_Click(object sender, EventArgs e)
        {
            textBox1.Text = (Math.Sqrt(2 * 10 * 100)).ToString();
        }
       

    }
}