Make A textBox Accept specific Characters from Keyboard

[vtops]

Dear All,


How can i make a textbox accept specific characters from keyboard.
While the user press a key i want to check the key. If the key is not that the system was expected do not appear it on the textbox.


For example i would like a textbox accept only numbers.
But if i press any other key except 0-9 do not show it on the textBox.



Best Regards

 

[JurkMonkey]

Capture the Keydown event. If the character is numeric then continue to process the keypress and if not, cancel it.


private void textBox1_Keydown(object Sender, KeyEventArgs e)
{
try
{
Convert.ToInt32((char)e.KeyCode);
}
catch
{
e.Handled = true;
}
}

 

[JurkMonkey]

Also, if you want to make it specific characters you will want to look at a Regex (Regular Expressions) and do a Match() on the incoming character.

Google Regex C#

 

[IT4EVR]

This is another way to handle this using the KeyPress event. This allows the user to either enter a number or a backspace.

For some reason, with the code above I was still able to type in non-numeric characters.

private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
		{
			if(!Char.IsNumber(e.KeyChar) && e.KeyChar != (char)8)
			{
				e.Handled = true;
			}

		}

The wisest people are those who are smart enough to realize they don't know it all.

 

[vtops]

Thank you everybody!

It is exactly that i was needing


Best Regards