private void ExpiryDate_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
char c = Convert.ToChar(e.Text);
if (Char.IsControl(c))
{
CardHolderName.Focus();
return;
}
int a = ExpiryDate.Text.ToCharArray().Where(f => Char.IsDigit(f)).Count();
if (Char.IsSurrogate(c) || Char.IsDigit(c) && a <= 3)
{
if (a % 2 == 0 && a != 0)
{
ExpiryDate.Text += "/";
ExpiryDate.SelectionStart = ExpiryDate.Text.Length;
CardHolderName.Focus();
ExpiryDate.Focus();
}
e.Handled = false;
}
else
{
e.Handled = true;
}
}
private void CardNumber_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
char c = Convert.ToChar(e.Text);
if (Char.IsControl(c))
{
ExpiryDate.Focus();
return;
}
int a = CardNumber.Text.ToCharArray().Where(f => f != ' ').Count();
if (Char.IsDigit(c) && a <= 15)
{
if (a % 4 == 0 && a != 0)
{
CardNumber.Text += " ";
CardNumber.SelectionStart = CardNumber.Text.Length;
CardHolderName.Focus();
CardNumber.Focus();
}
e.Handled = false;
}
else
{
e.Handled = true;
}
}