public virtual void KeyTyped(KeyEvent e)
{
int keyChar = e.GetKeyChar();
if (keyChar == unchecked((int)(0x8)))
{
if (outputMark == GetCaretPosition())
{
e.Consume();
}
}
else
{
if (GetCaretPosition() < outputMark)
{
SetCaretPosition(outputMark);
}
}
}