How to prevent zeros from being input before non-zero digits?

Question

In C#, WinForms how would you stop the following inputs:

0000000000001234556

0000.123456

00000123456.123456

Answer 1

If you want 1234556 instead of 000000001234556
Then you can convert it in Int,Double or any other Datatype as you want

2nd option is use the keypress event

private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
    {
        if (e.KeyCode == ascii of 0)
        {
            e.Handled = false;
        }
    }

Answer 2

You can override the KeyPress event and define a state that, if input is == '0' then ignore, else, wait for a non-zero input. Then change the state to accept 0s.

Since you do not show code, I will not either

Answer 3

You could add an event handler to the KeyDown or KeyPress events. Inside the event handler check if the KeyEventArgs KeyCode is 0 and if the length of your TextBox.Text property is 0. If so set the KeyEventArgs Handled property to false.