Question

I have next dependecy property:

public static DependencyProperty IsInReadModeProperty =
    DependencyProperty.Register("IsInReadMode", typeof(bool),
    typeof(RegCardSearchForm), new PropertyMetadata(false, ReadModeChanged));

and I have next method which handle Property changed event:

public static void ReadModeChanged(DependencyObject d,
    DependencyPropertyChangedEventArgs e)
{
    if ((bool)e.NewValue)
    {       
        btnSearch.Visibility = Visibility.Collapsed;
        btnExport.Visibility = Visibility.Collapsed;
        cbExportWay.Visibility = Visibility.Collapsed;
    }
}

But compiler give me error that i cannot acces non static buttons (btnSearch and e.t.c ) in static context.

I want change visibility of buttons when property value changed. How can I resolve this situation?

Answer 1

Since (non-attached) DependencyProperties are restricted to being set on their owner type you can just create an instance method to hold your logic and call that from the static method by casting the DependencyObject:

public static readonly DependencyProperty IsInReadModeProperty = DependencyProperty.Register(
    "IsInReadMode",
    typeof(bool),
    typeof(RegCardSearchForm),
    new UIPropertyMetadata(false, ReadModeChanged));

private static void ReadModeChanged(DependencyObject dObj, DependencyPropertyChangedEventArgs e)
{
    RegCardSearchForm form = dObj as RegCardSearchForm;
    if (form != null)
        form.ReadModeChanged((bool)e.OldValue, (bool)e.NewValue);
}

protected virtual void ReadModeChanged(bool oldValue, bool newValue)
{
    // TODO: Add your instance logic.
}