How disallow space, blank, ("_") charachter from text box input by keyboard

Question

How disallow space, blank, ("_") character from text box input by keyboard (WPF, C#)?

I try by code:

Regex regex = new Regex(@"^[A-Za-z0-9\[\]/!$%^&*()\-_+{};:'£@#.?]*$"); 

but this part of code disallow all character, but not space.

Answer 1

You can add PreviewKeyDown handler:

private void textBox_PreviewKeyDown(object sender, KeyEventArgs e)
{
    if (e.Key == Key.Space)
    {
        e.Handled = true;
    }
}

Now your textbox will ignore spaces.