The digit grouping code doesn't show the decimal symbol in textbox

Question

I have a calculator app that has a display like real calculators. Now I want to add digit grouping to it, that enhance the readability of the display. I added this code to my app, and it worked fine for integer numbers, but it doesn't show the fraction point in decimal numbers. I used double for defining the variables, but I don't know where the problem is.

private void txtDisplay_TextChanged(object sender, EventArgs e)
        {
            btnPoint.Enabled = !txtDisplay.Text.Contains(".");
            btnBackSpace.Enabled = Convert.ToBoolean(txtDisplay.Text.Length);

            //digit grouping the number in textbox

            if (txtDisplay.Text.Length > 0)
            {
                dblGroupedNumber = Convert.ToDouble(txtDisplay.Text);
                txtDisplay.Text = string.Format("{0:n0}", dblGroupedNumber);

            }
        }

Answer 1

it doesn't show the fraction point in decimal numbers.
txtDisplay.Text = string.Format("{0:n0}", dblGroupedNumber);

You appear to be suppressing the decimals with the
string format. Did you try this?

txtDisplay.Text = string.Format("{0:n2}", dblGroupedNumber);

• Wayne

Answer 2

Another possibility which shows significant trailing digits only:

txtDisplay.Text = string.Format("{0:n9}", dblGroupedNumber).TrimEnd('0');

• Wayne