fatura

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 elektrik_faturası__hesaplama

{

  public partial class Form1 : Form

  {

    public Form1()

    {

      InitializeComponent();

    }

    double İlkendeks, Sonendeks, Tüketim, KDVsizFiyat, KDV, KDVDahilFiyat,BirimFiyat;

    private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)

    {

      e.Graphics.DrawString("Abone Adı:"+textBox1.Text, new Font("arial", 16, FontStyle.Bold),

        Brushes.Black, 130, 125);

      e.Graphics.DrawString("okuma tarihi:"+dateTimePicker1.Text, new Font("arial", 16, FontStyle.Bold),

        Brushes.Black, 130, 150);

      e.Graphics.DrawString("KDV:"+textBox7.Text, new Font("arial", 16, FontStyle.Bold),

        Brushes.Black, 130, 175);

      e.Graphics.DrawString("son ödeme tarihi:"+dateTimePicker2.Text, new Font("arial", 16, FontStyle.Bold),

        Brushes.Black, 130, 200);

    }

    private void button3_Click(object sender, EventArgs e)

    {

      printDialog1.Document = printDocument1;

      if (printDialog1.ShowDialog() == DialogResult.OK)

      {

        printDocument1.Print(); 

      }

    }

    private void button2_Click(object sender, EventArgs e)

    {

      Application.Exit();

    }

    private void button1_Click(object sender, EventArgs e)

    {

      İlkendeks = Convert.ToDouble(textBox3.Text);

      Sonendeks = Convert.ToDouble(textBox4.Text);

      Tüketim = Sonendeks - İlkendeks;

      KDVsizFiyat = Tüketim * BirimFiyat;

      KDVDahilFiyat = KDVsizFiyat + (KDVsizFiyat * KDV);

      textBox5.Text = KDVsizFiyat.ToString();

      textBox8.Text = KDVDahilFiyat.ToString();

      textBox6.Text = KDVsizFiyat.ToString();

    }

    private void Form1_Load(object sender, EventArgs e)

    {

      dateTimePicker2.Value = dateTimePicker2.Value.AddDays(10);

    }

    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)

    {

      if (comboBox1.SelectedIndex == 0) 

      {

        BirimFiyat = 2.6;

        KDV = 8;

      }

      else 

      {

        BirimFiyat = 3.3;

        KDV = 18;

      }

      textBox2.Text = BirimFiyat.ToString();

      textBox7.Text = KDV.ToString();

    }

  }

}