Create Calculator Using C# Program

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 Calculator {
    public partial class Form1: Form {
        public Form1() {
            InitializeComponent();
        }
        float num1, ans;
        int count;
        //int result;
        ServiceReference1.CalculatorClient obj = new ServiceReference1.CalculatorClient();
        private void btnDivide_Click(object sender, EventArgs e) {
            num1 = int.Parse(textBox1.Text);
            textBox1.Clear();
            textBox1.Focus();
            count = 4;
        }
        private void btnC_Click(object sender, EventArgs e) {
            textBox1.Clear();
            count = 0;
        }
        private void btnCE_Click(object sender, EventArgs e) {
            if (num1 == 0 && textBox1.TextLength > 0) {
                num1 = 0;
                textBox1.Clear();
            } else if (num1 > 0 && textBox1.TextLength > 0) {
                textBox1.Clear();
            }
        }
        private void btnDelete_Click(object sender, EventArgs e) {
            int length = textBox1.TextLength - 1;
            string text = textBox1.Text;
            textBox1.Clear();
            for (int i = 0; i < length; i++) {
                textBox1.Text = textBox1.Text + text[i];
            }
        }
        private void btnminus_Click(object sender, EventArgs e) {
            if (textBox1.Text != "") {
                num1 = float.Parse(textBox1.Text);
                textBox1.Clear();
                textBox1.Focus();
                count = 1;
            }
        }
        private void btn1_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 1;
        }
        private void btn2_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 2;
        }
        private void btn3_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 3;
        }
        private void btn4_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 4;
        }
        private void btn5_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 5;
        }
        private void btn6_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 6;
        }
        private void btn7_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 7;
        }
        private void btn8_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 8;
        }
        private void btn9_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 9;
        }
        private void btnMultiply_Click(object sender, EventArgs e) {
            num1 = float.Parse(textBox1.Text);
            textBox1.Clear();
            textBox1.Focus();
            count = 3;
        }
        private void btn0_Click(object sender, EventArgs e) {
            textBox1.Text = textBox1.Text + 0;
        }
        private void btnPeriod_Click(object sender, EventArgs e) {
            int c = textBox1.TextLength;
            int flag = 0;
            string text = textBox1.Text;
            for (int i = 0; i < c; i++) {
                if (text[i].ToString() == ".") {
                    flag = 1;
                    break;
                } else {
                    flag = 0;
                }
            }
            if (flag == 0) {
                textBox1.Text = textBox1.Text + ".";
            }
        }
        private void btnEqual_Click(object sender, EventArgs e) {
            compute(count);
        }
        private void compute(int count) {
            switch (count) {
                case 1:
                    ans = num1 - float.Parse(textBox1.Text);
                    textBox1.Text = ans.ToString();
                    break;
                case 2:
                    ans = num1 + float.Parse(textBox1.Text);
                    textBox1.Text = ans.ToString();
                    break;
                case 3:
                    ans = num1 * float.Parse(textBox1.Text);
                    textBox1.Text = ans.ToString();
                    break;
                case 4:
                    ans = num1 / float.Parse(textBox1.Text);
                    textBox1.Text = ans.ToString();
                    break;
                default:
                    break;
            }
        }
        private void btnAdd_Click(object sender, EventArgs e) {
            num1 = float.Parse(textBox1.Text);
            textBox1.Clear();
            textBox1.Focus();
            count = 2;
        }
    }
}