Question

I have the below code.
There is a small issue when I typed more than 2 numbers after the “.”, it will keep on prompting me (“No more than two decimal places.”)…

It will also prompt me the message when I have .XX and clicked on backspace.

How can I auto erase the 3rd number after the “.”?

private void textbox1_PreviewKeyDown(object sender, KeyEventArgs e)
{
    if (e.Key == Key.Space)
    {
        MessageBox.Show("No space allowed.");
        e.Handled = true;
    }
    string[] array = textbox1.Text.Split(new char[] { '.' });
    if (array.Length == 2)
    {
        if (array[1].Length == 2)
        {
            MessageBox.Show("No more than two decimal places.");
            e.Handled = true;
        }
    }
}

Answer 1

I used

if (e.Key != Key.Back)

to stop the Backspace issue.

Now it’s okay.