Limiting what a textbox can contain

Question

Hi I'm a newbie using Visual C# 2008 and i ran into a problem. i need a textbox to contain only numbers and i don't know how to stop the user from inputing other characters(except adding a label that says don't input other characters! :)). also i don't know how to check what's already inputed by a user into a textbox(i'd normally check the ascii values of the characters but i'm sure C# has it's own way). Thanks hristo

Aleksandar Hristovski · Answer

Thanks! Works great!

Niradhip Chakraborty · Answer

Try this: private void txtZip_KeyPress(object sender KeyPressEventArgs e) { if (char.IsDigit(e.KeyChar) || char.IsControl(e.KeyChar)) { e.Handled = false; } else { e.Handled = true; } }

Aleksandar Hristovski · Answer

It's for Windows

Ryan Alford · Answer

Is this for Windows or Web?

Aleksandar Hristovski · Answer

I thought there was a C# inbuilt function for it (since it seems it has inbuilt functions for everything! :). Thanks!

Niradhip Chakraborty · Answer

Use the following java script function and call it on keypress event of textbox. function isNumberKey(evt){ var charCode = (evt.which) ? evt.which : event.keyCode if (charCode > 31 && (charCode 57)){ alert(Please enter digits); return false; } else{ return true; } }