设置RadNumericBox Focus Telerik WPF的属性

Question

I am trying to set Focus to RadNumericBox Telerik Control. There is no property for the control to set the Focus values.

Although, I can do it in my code behind by getting the VisualChild of NumericTextBox and setting the Focus values.

    NumericTextBox box1 = VisualTreeUtilities.GetVisualChild<NumericTextBox>(RadNumericBox1);
    box1.Focus(FocusState.Programmatic);

But I need to change the Focus in the Viewmodel. So I am looking for a property, so that viewmodel can be binded to it.

Answer 1

In general to manipulate focus and other such visual procedures, I would recommend you to create a custom Attached Property on UIElement and then when that property is set you can set focus to UIElement

    public static class FocusExtension
    {

        public static bool GetFocused(DependencyObject obj)
        {
            return (bool)obj.GetValue(FocusedProperty);
        }


        public static void SetFocused(DependencyObject obj, bool value)
        {
            obj.SetValue(FocusedProperty, value);
        }


        public static readonly DependencyProperty FocusedProperty =
               DependencyProperty.RegisterAttached("Focused",
               typeof(bool), typeof(FocusExtension),
               new UIPropertyMetadata(false, OnFocusedPropertyChanged));

        private static void OnFocusedPropertyChanged(DependencyObject d,
            DependencyPropertyChangedEventArgs e)
        {
            var uiElement = (UIElement)d;
            var toSet = (bool)e.NewValue;
            if (toSet)
            {
                uiElement.Focus();
            }
        }
    }