Today in this article I will show you how to make a simple basic calculator in C#.
Global variables
// Global variables
private double FirstNumber = 0.0;
private double SecondNumber = 0.0;
private string OperatorString = "+";
private double Result = 0.0;
Diagram
![calculator]()
Button events//zero button click event
private void ZeroButton_Click(object sender, EventArgs e)
{
ZeroRemove(0);
}
//zero remove function and here other number will add on the texbox
private void ZeroRemove(int number)
{
if (CalcTextBox.Text == "0")
CalcTextBox.Text =number.ToString();
else
CalcTextBox.Text += number.ToString();
}
//three button click event
private void OneButton_Click(object sender, EventArgs e)
{
ZeroRemove(1);
}
//three button click event
private void TwoButton_Click(object sender, EventArgs e)
{
ZeroRemove(2);
}
//three button click event
private void ThreeButton_Click(object sender, EventArgs e)
{
ZeroRemove(3);
}
private void FourButton_Click(object sender, EventArgs e)
{
ZeroRemove(4);
}
private void FiveButton_Click(object sender, EventArgs e)
{
ZeroRemove(5);
}
private void SixButton_Click(object sender, EventArgs e)
{
ZeroRemove(6);
}
private void SevenButton_Click(object sender, EventArgs e)
{
ZeroRemove(7);
}
private void EightButton_Click(object sender, EventArgs e)
{
ZeroRemove(8);
}
private void NineButton_Click(object sender, EventArgs e)
{
ZeroRemove(9);
}
//Clear button click event here clear the texbox
private void ClearButton_Click(object sender, EventArgs e)
{
CalcTextBox.Clear();
CalcTextBox.Text = "0";
FirstNumber = 0.0;
SecondNumber = 0.0;
Result = 0.0;
}
//Here put . in the textbox
private void DoBtutton_Click(object sender, EventArgs e)
{
if (!CalcTextBox.Text.Contains("."))
CalcTextBox.Text += ".";
}
//plus button
private void PlusButton_Click(object sender, EventArgs e)
{
SuppliedOperator("+");
}
// It is general function which recieve the coming operator
private void SuppliedOperator(string operatorString)
{
OperatorString = operatorString;
FirstNumber = double.Parse(CalcTextBox.Text);
CalcTextBox.Text = "0";
}
private void MinusButton_Click(object sender, EventArgs e)
{
SuppliedOperator("-");
}
private void DivisionButton_Click(object sender, EventArgs e)
{
SuppliedOperator("/");
}
private void MultiplyButton_Click(object sender, EventArgs e)
{
SuppliedOperator("*");
}
//Equal button
private void EqualButton_Click(object sender, EventArgs e)
{
SecondNumber = double.Parse(CalcTextBox.Text);// here recieve second number from the user.
switch (OperatorString)// switch
{
case "+":
Result = FirstNumber + SecondNumber;
break;
case "-":
Result = FirstNumber - SecondNumber;
break;
case "/":
Result = FirstNumber / SecondNumber;
break;
case "*":
Result = FirstNumber * SecondNumber;
break;
case "%":
Result = FirstNumber % SecondNumber;
break;
case "sin":
Result = System.Math.Sin(FirstNumber);
break;
case "cos":
Result = System.Math.Cos(FirstNumber);
break;
case "tan":
Result = System.Math.Tan(FirstNumber);
break;
}
CalcTextBox.Text = Result.ToString();
}
private void MinusPlusButton_Click(object sender, EventArgs e)
{
if (!CalcTextBox.Text.Contains("-"))
CalcTextBox.Text = "-" + CalcTextBox.Text;
else
CalcTextBox.Text = CalcTextBox.Text.Trim('-');
}
private void PercentageButton_Click(object sender, EventArgs e)
{
SuppliedOperator("%");
}
//sin button
private void SinButton_Click(object sender, EventArgs e)
{
SuppliedOperator("sin");
}
private void CosButton_Click(object sender, EventArgs e)
{
SuppliedOperator("cos");
}
//cos button
private void TanButton_Click(object sender, EventArgs e)
{
SuppliedOperator("cos");
}
I have also attached the source code so you can download it and run it in your PC.