UWP中的FrameworkPropertyMetadata在哪里？

Question

和/或如何DependencyProperty在我的控件上定义一个sepcifies AffectsMeasure？

编辑:哦,刚看到这一点-我必须叫InvalidateMeasure上this在propertychangedhandler？

Answer 1

对不起。不支持UWP AffectsMeasure 。对于 Framework 3+ 它有效。对于默认的 UWP 绑定，我正在使用 CodeSnipped 功能。通过事件处理，您可以表现得透明。对于我的模型，UWP 的 codeSnippet 结果如下所示：

    #region IsSelected

    public static readonly DependencyProperty IsSelectedProperty =
        DependencyProperty.Register("IsSelected", typeof(bool), typeof(PositionModel),
            new PropertyMetadata((bool)false,
                new PropertyChangedCallback(OnIsSelectedChanged)));

    public bool IsSelected
    {
        get { return (bool)GetValue(IsSelectedProperty); }
        set { SetValue(IsSelectedProperty, value); }
    }

    private static void OnIsSelectedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        PositionModel target = (PositionModel)d;
        bool oldIsSelected = (bool)e.OldValue;
        bool newIsSelected = target.IsSelected;
        target.OnIsSelectedChanged(oldIsSelected, newIsSelected);
    }

    protected virtual void OnIsSelectedChanged(bool oldIsSelected, bool newIsSelected)
    {
       // Do what your need in your property changed event
       // In my case, I just raise the PropertyChanged for PropertyChangedEventHandler
       // RaisePropertyChanged(nameof(IsSelected));
    }
    #endregion

XAML：

<Rectangle Fill="Black" Visibility="{x:Bind IsSelected, Mode=OneWay, Converter={StaticResource BoolToVis}}" />

Windows 10、应用商店、VS 2017、Microsoft.NETCore.UniversalWindowsPlatform 版本 5.2.3