In this blog we will see how to test whether a
given number entered in a textbox is a valid integer or an invalid integer.
using
System;
using
System.Collections.Generic;
using
System.ComponentModel;
using
System.Data;
using
System.Drawing;
using
System.Linq;
using
System.Text;
using
System.Windows.Forms;
namespace
Valid_or_Invalid_integer
{
public partial
class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void
btn_valid_invalid_Click(object sender,
EventArgs e)
{
int i;
bool isValidInteger =
int.TryParse(textBox1.Text, out i);
if (!isValidInteger)
{
MessageBox.Show("Not a valid integer.Please enter
once again!");
textBox1.Focus();
return;
}
else
{
MessageBox.Show("Valid integer");
textBox1.Focus();
}
}
}
}