Question

I have MyContainer User Control with Grid inside. Each cell of this Grid contains a some control derived from MyControlBase class. These controls are added dynamically.

I need to implement a FocusedControl bound property in MyContainer to get currently focused or set focus to any of MyControlBase children. I know about FocusManager.FocusedElement but haven’t ideas how to implement it properly.

Answer 1

OK, I found how to do it myself.

First define our new dependence property FocusedAdapterProperty as usual:

    public static readonly DependencyProperty FocusedAdapterProperty;

    static SpreadGridControl()
    {
        FocusedAdapterProperty = DependencyProperty.Register("FocusedAdapter",
                            typeof(object), typeof(SpreadGridControl),
                            new FrameworkPropertyMetadata(null, null));
    }

    public object FocusedAdapter
    {
        get { return GetValue(FocusedAdapterProperty); }
        set { SetValue(FocusedAdapterProperty, value); }
    }

Next add GotFocus handler to parent container e.g. <Grid GotFocus="Grid_OnGotFocus">
Check the e.OriginalSource and search most common ancestor of required type and set property to new value:

    private void Grid_OnGotFocus(object sender, RoutedEventArgs e)
    {
        var control = UIHelpers.TryFindParent<ControlBase>
            ((DependencyObject)e.OriginalSource);
        if (control != null)
            FocusedAdapter = control.Adapter;
    }

The implementation of TryFindParent can be found here