private void UpdateLineNumbers()
{
Point pt = new Point(0, 0);
int firstIndex = MainTextBox.GetCharIndexFromPosition(pt);
int firstLine = MainTextBox.GetLineFromCharIndex(firstIndex);
pt.X = ClientRectangle.Width;
pt.Y = ClientRectangle.Height;
int lastIndex = MainTextBox.GetCharIndexFromPosition(pt);
int lastLine = MainTextBox.GetLineFromCharIndex(lastIndex);
LineNumbers.SelectionAlignment = HorizontalAlignment.Center;
LineNumbers.Text = "";
LineNumbers.Width = GetWidth();
if (MainTextBox.Lines.Length > 1)
{
for (int i = firstLine; i <= lastLine + 1; i++)
{
int lineNum = (i + 1);
if (lineNum <= Lines.Length)
{
LineNumbers.Text += (i + 1) + "\n";
}
}
}
else
{
LineNumbers.Text += 1 + "\n";
}
}
