title: WPF - how to focus an usercontrol from code behind
body: <p>I have an user control with <code>Focusable=true</code> and <code>IsTabStop=true</code>.</p>
  
  <p>I can focus it using Tab key. but I need to focus it from code. </p>
  
  <p>I tried <code>uc.Focus()</code> and <code>Keyboard.Focus(uc)</code> but it doesn't work. </p>