How do I prevent user from entering strings other than numeric onto the textbox?

[PlayKid]

Dear all,

 

How do I do that? To prevent user from entering "abcd", the user may only enter "1234".....

Say if the user enter something that's not numeric, then the textbox won't response....

 

Thanks

 

PlayKid

[jmcilhinney]

This question is definitely in the top 10 most asked. Do a forum search and you'll find your answer.

[techmanbd]

 Private Sub txtCalledNumber_KeyPress(ByVal sender As System.Object, ByVal e As KeyPressEventArgs) Handles txtCalledNumber.KeyPress
       If Not Char.IsNumber(e.KeyChar) And Not Asc(e.KeyChar) = Keys.Back Then
           e.Handled = True
       End If
   End Sub  

 

kEYS.BACK is for the back space. That way if you make a mistake you can still use the backspace key

[Bucky]

If you use techmanbd's code and you want the user to be able to enter decimals, then make sure you allow the "." character as well.

 

Or just skip all the validation and use a NumericUpDown control.