# Calculator in C#

Description

This is basic Calculator program written in C# which makes use of the Windows Form,Panel etc.

Basic mathematical functions like Addition, Subtraction, Multiplication and division can be performed using this Calculator.

Source Code:

using System;
using System.Windows.Forms;
using System.Drawing;
public
class win:Form
{
Button[] b =
new Button[10];
Button bDot,bPlus,bSub,bMul,bDiv,bEqu,bClr;
Panel panCalc;
TextBox txtCalc;
Double dblAcc;
Double dblSec;
bool blnClear,blnFrstOpen;
String strOper;

public
win()
{
try
{
this.Text="Calculator";
panCalc=
new Panel();
txtCalc =
new TextBox();
txtCalc.Location =
new Point(10,10);
txtCalc.Size=
new Size(150,10);
true;
txtCalc.RightToLeft=RightToLeft.Yes;
panCalc.Size=
new Size(200,200);
panCalc.BackColor=Color.Aqua;
this.Size=new Size(200,225);
dblAcc=0;
dblSec=0;
blnFrstOpen=
true;
blnClear=
false;
strOper=
new String('=',1);
}
catch (Exception e)
{
Console.WriteLine("error ...... " + e.StackTrace);
}
}

private
{
for (int i=0;i<=9;i++)
{
b[i]=
new Button();
b[i].Text=Convert.ToString(i);
b[i].Size=
new Size(25,25);
b[i].BackColor=Color.White;
b[i].Click+=
new EventHandler(btn_clk);
}
b[0].Location=
new Point(10,160);
b[1].Location=
new Point(10,120);
b[4].Location=
new Point(10,80);
b[7].Location=
new Point(10,40);
b[2].Location=
new Point(50,120);
b[5].Location=
new Point(50,80);
b[8].Location=
new Point(50,40);
b[3].Location=
new Point(90,120);
b[6].Location=
new Point(90,80);
b[9].Location=
new Point(90,40);
bDot=
new Button();
bDot.Size=
new Size(25,25);
bDot.Location=
new Point(50,160);
bDot.BackColor=Color.White;
bDot.Text=".";
bDot.Click+=
new EventHandler(btn_clk);
bPlus=
new Button();
bPlus.Size=
new Size(25,25);
bPlus.Location=
new Point(130,160);
bPlus.BackColor=Color.White;
bPlus.Text="+";
bPlus.Click+=
new EventHandler(btn_Oper);
bSub=
new Button();
bSub.Size=
new Size(25,25);
bSub.Location=
new Point(130,120);
bSub.BackColor=Color.White;
bSub.Text="-";
bSub.Click+=
new EventHandler(btn_Oper);
bMul=
new Button();
bMul.Size=
new Size(25,25);
bMul.Location=
new Point(130,80);
bMul.BackColor=Color.White;
bMul.Text="*";
bMul.Click+=
new EventHandler(btn_Oper);
bDiv=
new Button();
bDiv.Size=
new Size(25,25);
bDiv.Location=
new Point(130,40);
bDiv.BackColor=Color.White;
bDiv.Text="/";
bDiv.Click+=
new EventHandler(btn_Oper);
bEqu=
new Button();
bEqu.Size=
new Size(25,25);
bEqu.Location=
new Point(90,160);
bEqu.BackColor=Color.White;
bEqu.Text="=";
bEqu.Click+=
new EventHandler(btn_equ);
bClr=
new Button();
bClr.Size=
new Size(20,45);
bClr.Location=
new Point(170,40);
bClr.BackColor=Color.Orange;
bClr.Text="AC";
bClr.Click+=
new EventHandler(btn_clr);
}

private
void btn_clk(object obj,EventArgs ea)
{
if(blnClear)
txtCalc.Text="";
Button b3=(Button)obj;
txtCalc.Text+=b3.Text;
if (txtCalc.Text==".")
txtCalc.Text="0.";
dblSec=Convert.ToDouble(txtCalc.Text);
blnClear=
false;
}

private
static void Main()
{
Application.Run(
new win());
}

private
void btn_Oper(object obj,EventArgs ea)
{
Button tmp=(Button)obj;
strOper=tmp.Text;
if (blnFrstOpen)
dblAcc=dblSec;
else
calc();
blnFrstOpen=
false;
blnClear=
true;
}

private
void btn_clr(object obj,EventArgs ea)
{
clear();
}

private
void btn_equ(object obj,EventArgs ea)
{
calc();
}

private
void calc()
{
switch(strOper)
{
case "+":
dblAcc+=dblSec;
break;
case "-":
dblAcc-=dblSec;
break;
case "*":
dblAcc*=dblSec;
break;
case "/":
dblAcc/=dblSec;
break;
}
strOper="=";
blnFrstOpen=
true;
txtCalc.Text=Convert.ToString(dblAcc);
dblSec=dblAcc;
}
private void clear()
{
dblAcc=0;
blnFrstOpen=
true;
txtCalc.Text="";
txtCalc.Focus();
}
}