title: How disallow space, blank, ("_") charachter from text box input by keyboard
body: <p>How disallow space, blank, (<code>"_"</code>) character from text box input by keyboard (WPF, C#)?</p>
  
  <p>I try by code: </p>
  
  <pre><code>Regex regex = new Regex(@"^[A-Za-z0-9\[\]/!$%^&amp;*()\-_+{};:'£@#.?]*$"); 
  </code></pre>
  
  <p>but this part of code disallow all character, but not space.</p>