如何实现ReactiveUI ObservedChange？

Question

我想使用EventHandler MouseEnter和MouseLeave来更改图像的OpasityMask，该图像将在运行时在不同页面上生成。关键是我需要访问发件人才能更改类ViewModel 上OpacityMask命令的属性MouseHover。

查看

this.WendActivated(d =>
{
    d(this.BindCommand(ViewModel, 
       vm => vm.MouseHover, 
       v => v.myImage, 
       myImage.Events().MouseEnter));
});

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ViewModel

private void Image_MouseEnterExecute(object sender, MouseEventArgs e)
{
    PlaySound("mouse_hover.mp3");

    var image = sender as Image;
    image.OpacityMask = new SolidColorBrush { Opacity = 1, Color = Colors.Black };
}

我不知道如何实施事件来更改OpacityMask

public ReactiveCommand MouseHover => image_MouseEnter;
public ObservedChange<object, object> ImageBrush => imageBrush;

public ViewModel()
{
    //Can not convert method group to action.
    image_MouseEnter = ReactiveCommand.Create(Image_MouseEnterExecute);
    //Can not convert method group to action.
    imageBrush = ReactiveCommand.Create(Image_MouseEnterExecute);
}

为什么我不设置对属性OpacityMask的绑定，问题是我有很多图像是在运行时创建的。我不希望所有图像同时更改，也不希望为每个图像创建一个OpacityMask属性。

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我希望有经验的人可以帮助我。