C# Numeric Only TextBox Control [duplicate]

Question

I am using C#.NET 3.5, and I have a problem in my project. In C# Windows Application, I want to make a textbox to accept only numbers. If user try to enter characters message should be appear like "please enter numbers only", and in another textbox it has to accept valid email id message should appear when it is invalid. It has to show invalid user id.

Answer 1

use this code:

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            const char Delete = (char)8;
            e.Handled = !Char.IsDigit(e.KeyChar) && e.KeyChar != Delete;
        }