protected void NumButton_Click(object sender, EventArgs e)
{
Button Button = (Button)sender;
string ButtonText = Button.Text;
// if the last entry is a digit, append the digit to the number;
// if not, aka the last entry is an operand, create a new number string with the digit
if (char.IsDigit(LastEntry))
{
if (CurrNumberString == "0")
{
CurrNumberString = ButtonText;
}
else
{
CurrNumberString = CurrNumberString.Insert(CurrNumberString.Length, ButtonText);
}
}
else
{
CurrNumberString = ButtonText;
}
Expression = Expression.Insert(Expression.Length, ButtonText);
LastEntry = Expression[Expression.Length - 1];
CurrNumberText.Text = CurrNumberString;
Session["CurrNumberString"] = CurrNumberString;
Session["Expression"] = Expression;
Session["LastEntry"] = LastEntry;
Session["Operation"] = Operation;
}
protected void ButtonDOT_Click(object sender, EventArgs e)
{
Button Button = (Button)sender;
string ButtonText = Button.Text;
// if last entry is a digit, append the dot to the number string;
// if not, aka the last entry is an operand, create a new number string "0." and change last entry to 0
if (char.IsDigit(LastEntry))
{
CurrNumberString = CurrNumberString.Insert(CurrNumberString.Length, ButtonText);
Expression = Expression.Insert(Expression.Length, ButtonText);
}
else
{
CurrNumberString = "0.";
Expression = Expression.Insert(Expression.Length, CurrNumberString);
LastEntry = '0';
}
CurrNumberText.Text = CurrNumberString;
Session["CurrNumberString"] = CurrNumberString;
Session["Expression"] = Expression;
Session["LastEntry"] = LastEntry;
}
protected void ButtonDEL_Click(object sender, EventArgs e)
{
if (char.IsDigit(LastEntry))
{
if (CurrNumberString.Length > 1)
{
CurrNumberString = CurrNumberString.Substring(0, CurrNumberString.Length - 1);
Expression = Expression.Substring(0, Expression.Length - 1);
}
else
{
if (CurrNumberString.Length == 1 & CurrNumberString != "0")
{
Expression = Expression.Substring(0, Expression.Length - 1);
}
CurrNumberString = "0";
}
}
CurrNumberText.Text = CurrNumberString;
Session["CurrNumberString"] = CurrNumberString;
Session["Expression"] = Expression;
}
protected void OpButton_Click(object sender, EventArgs e)
{
Button Button = (Button)sender;
string ButtonText = Button.Text;
// if last entry is a digit, calculate the new result and record the new operand and add it to the expression
if (char.IsDigit(LastEntry))
{
Operation.SecondNumber = Double.Parse(CurrNumberString);
CurrNumberString = Math.Round(Operation.Calculate(), 10).ToString();
Operation.FirstNumber = Double.Parse(CurrNumberString);
Operation.Operand = ButtonText;
if (Expression == "")
{
Expression = CurrNumberString;
}
Expression = Expression.Insert(Expression.Length, ButtonText);
LastEntry = Expression[Expression.Length - 1];
}
else if (LastEntry == '=')
{
Expression = CurrNumberString.Insert(CurrNumberString.Length, ButtonText);
LastEntry = Expression[Expression.Length - 1];
}
// if last entry is not a digit, aka it's an operand, update the operation and change the expression and last entry
else
{
Operation.Operand = ButtonText;
if (Expression != "")
{
Expression = Expression.Remove(Expression.Length - 1);
}
else
{
Expression = CurrNumberString;
}
Expression = Expression.Insert(Expression.Length, ButtonText);
LastEntry = Expression[Expression.Length - 1];
}
ExpressionText.Text = Expression;
CurrNumberText.Text = CurrNumberString;
if (Operation.OperationFlag == 1)
{
CurrNumberText.Text = "Cannot divide by zero";
CurrNumberString = "0";
Expression = "";
ExpressionText.Text = Expression;
LastEntry = '0';
Operation.OperationFlag = 0;
}
else if (Operation.OperationFlag == 2)
{
CurrNumberText.Text = "Result is undefined";
CurrNumberString = "0";
Expression = "";
ExpressionText.Text = Expression;
LastEntry = '0';
Operation.OperationFlag = 0;
}
Session["CurrNumberString"] = CurrNumberString;
Session["Expression"] = Expression;
Session["LastEntry"] = LastEntry;
Session["Operation"] = Operation;
}