float.TryParse not working

I created program that calculates the currency exchange rate. The program has:

1. ComboboxCurrencyName - which displays the currency name.
2. ComboCurrencyValue - which displays the value of a given currency.
3. txtYourValue - textbox which gets from user the amount of money
4. Button that calculates the rate of the given currency with the amount of money given from user.

My code:

public void EchangeRate(float x,float y)
{ label1.Text = (x * y).ToString();
}
private void button1_Click(object sender, EventArgs e)
{ if(comboCurrencyName.SelectedIndex==comboCurrencyValue.SelectedIndex) { float currency; float inputValue; if(float.TryParse(comboCurrencyValue.SelectedItem.ToString(),out currency)&& float.TryParse(txtYourValue.Text,out inputValue)) { EchangeRate(currency,inputValue); } } else { MessageBox.Show("Not selected currency "); }
}

When I select a given currency with a combobox and I'm entering the value to convert, nothing happens when I press the button. I think this is a problem with converting combobox to float value.

Previously I used float.Parse() I had the error:

System.FormatException: 'Invalid input string format.

Breakpoint

1 Answer

Replace with:

(float.TryParse(comboCurrencyValue.SelectedItem.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture,out currency)&& float.TryParse(txtYourValue.Text,out inputValue)) 

To explain: in Poland a comma is used instead of a decimal point, so you must specify that you want to use an invariant culture.