WPF: How to programmatically remove focus from a TextBox

A bit late to the party, but it was helpful to me so here it goes.

Since .Net 3.0, FrameworkElement has a MoveFocus function which did the trick for me.

Since none of the above answers worked for me and the accepted answer does work only for a keyboard focus, I came to the following approach:

// Kill logical focus
FocusManager.SetFocusedElement(FocusManager.GetFocusScope(textBox), null);
// Kill keyboard focus
Keyboard.ClearFocus();

Kills both, logical as well as the keyboard focus.

in .NET Framework 4 just Keyboard.ClearFocus();

The code I have been using :

// Move to a parent that can take focus
FrameworkElement parent = (FrameworkElement)textBox.Parent;
while (parent != null && parent is IInputElement && !((IInputElement)parent).Focusable)
{
    parent = (FrameworkElement)parent.Parent;
}

DependencyObject scope = FocusManager.GetFocusScope(textBox);
FocusManager.SetFocusedElement(scope, parent as IInputElement);