我有点惊讶的是,无法通过XAML为Canvas.Children设置绑定.我不得不采用代码隐藏方法,看起来像这样:
private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
DesignerViewModel dvm = this.DataContext as DesignerViewModel;
dvm.Document.Items.CollectionChanged += new System.Collections.Specialized.NotifyCollectionChangedEventHandler(Items_CollectionChanged);
foreach (UIElement element in dvm.Document.Items)
designerCanvas.Children.Add(element);
}
private void Items_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
ObservableCollection<UIElement> collection = sender as ObservableCollection<UIElement>;
foreach (UIElement element in collection)
if (!designerCanvas.Children.Contains(element))
designerCanvas.Children.Add(element);
List<UIElement> removeList = new List<UIElement>();
foreach (UIElement element in designerCanvas.Children)
if (!collection.Contains(element))
removeList.Add(element);
foreach (UIElement element in removeList)
designerCanvas.Children.Remove(element);
}
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我更喜欢在XAML中设置一个绑定,如下所示:
<Canvas x:Name="designerCanvas"
Children="{Binding Document.Items}"
Width="{Binding Document.Width}"
Height="{Binding Document.Height}">
</Canvas>
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有没有办法在不采用代码隐藏方法的情况下实现这一目标?我已经完成了一些关于这个主题的谷歌搜索,但是对于这个具体问题还没有提出太多.
我不喜欢我当前的方法,因为它通过使View知道它的ViewModel来破坏我的漂亮的Model-View-ViewModel.