Input string was not in a correct format - Slot Mchine App

Question

I get the error: 'Input string was not in a correct format'..... I am running an if else calculation and then populating a label with the result the variable is declared as decimal then ToString('C') to the label...

List<string> moneyWon = new List<string>();

     private void calculateAmountWon()
     {
         moneyWon.Add(amountWonlabel.Text);

         decimal won = moneyWon.Sum(str => Convert.ToInt32(str));             

         moneyWonLabel.Text = won.ToString("C");
      }

    private void button2_Click(object sender, EventArgs e)
    {
        this.Close();
    }

Answer 1

Based on what you're outputting I'm assuming that your strings are formatted as currency with a currency symbol and two decimal places. If that's the case you can change your parsing to:

decimal won = moneyWon.Sum(str => decimal.Parse(str, NumberStyles.Currency));

You're still vulnerable to invalid formats but if the values are all set programatically then they should be predictable.

Another option is to use a list of numeric types and parse up front:

List<decimal> moneyWon = new List<decimal>();

private void calculateAmountWon()
{
     moneyWon.Add(decimal.Parse(amountWonlabel.Text, NumberStyles.Currency));

     decimal won = moneyWon.Sum();             

     moneyWonLabel.Text = won.ToString("C");
}