Set focus on textbox in WPF

Question

How to set the focus on an TextBox element in WPF

I have this code:

txtCompanyID.Focusable = true;
txtCompanyID.Focus();

Answer 1

None of this worked for me as I was using a grid rather than a StackPanel.

I finally found this example: http://spin.atomicobject.com/2013/03/06/xaml-wpf-textbox-focus/

and modified it to this:

In the 'Resources' section:

In my grid definition: