private bool IsValidInteger (out int result, TextBox txt, string name, int min = int.MinValue, int max = int.MaxValue)
{
// Get the text.
string text = txt. Text;
// If there is something wrong, build an error message.
string message = "";
if (text.Length == 0) message = "Please enter " + name + " . ";
else if (!int.TryParse (text, out result))
message = "Error parsing " + name + " '" + text + "'";
else if ((result < min) || (result > max))
message = name + " must be between " + min.ToString() + " and " + max.ToString() + ".";
// See if we have an error message.
if (message.Length > 0)
{
// Display the message, select the Textbox's text.
// give it focus, and return false.
MessageBox. Show (message, name + "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
txt.Select (0, text.Length);
txt. Focus();
return false;
}
// The value is okay.
return true;
}