我有一个TabControl，每个选项卡都可以包含相同的UI但具有不同的数据。在任何选项卡中，用户都可以单击按钮并弹出一个窗口。这将设置Style属性到ViewModel，告诉它使用哪种样式来显示弹出UI。Style绑定到自定义DependecyProperty，该属性附加到自定义PopupUserControl。我的问题是，当第二个弹出窗口在另一个选项卡中打开时，无论应用何种样式，我都会收到以下错误消息：
触发ViewModelBase中的OnPropertyChanged事件。
错误发生在ViewModelBase中的
失败的样式与成功的样式之间的主要区别是它们位于不同的位置。 编辑 #2 失败的样式-LookupDialog是自定义的WPF UserControl。
指定的元素已经是另一个元素的逻辑子级。请先断开连接。
ButtonClick命令：
MyViewModel vm = ((Button)sender).DataContext as MyViewModel;
if (vm != null)
{
Style popupStyle = (Style)Application.Current.FindResource("SomePopupStyle");
vm.EditPanelStyle= popupStyle ;
}
这将在样式上触发一个PropertyChange事件。
public Style EditPanelStyle
{
get { return _editPanelStyle; }
set
{
if (_editPanelStyle != value)
{
_editPanelStyle = value;
OnPropertyChanged("EditPanelStyle");
}
}
}
触发ViewModelBase中的OnPropertyChanged事件。
protected virtual void OnPropertyChanged(string propertyName)
{
this.VerifyPropertyName(propertyName);
PropertyChangedEventHandler handler = this.PropertyChanged;
if (handler != null)
{
var e = new PropertyChangedEventArgs(propertyName);
handler(this, e);
}
}
错误发生在ViewModelBase中的
handler(this, e);行。
编辑
TabItem包含一个Canvas和一堆可以添加/删除/移动等的面板。每个面板都有自己的资源目录。从面板内部，我可以很好地设置PopupStyle，并且没有问题地应用它。在面板中使用的样式也在PanelResourceDictionary中定义。失败的样式与成功的样式之间的主要区别是它们位于不同的位置。 编辑 #2 失败的样式-LookupDialog是自定义的WPF UserControl。
<!-- Popup Style for LookupDialog -->
<Style x:Key="LookupDialogBaseStyle" TargetType="{x:Type localControls:DraggablePanel}" BasedOn="{StaticResource GenericPopupStyle}">
<Setter Property="Canvas.Left" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type localControls:PopupPanel}},
Path=ActualWidth, Converter={StaticResource PercentToDoubleConverter}, ConverterParameter=.25}" />
<Setter Property="Canvas.Top" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type localControls:PopupPanel}},
Path=ActualHeight, Converter={StaticResource PercentToDoubleConverter}, ConverterParameter=.3}" />
<Setter Property="Width" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type localControls:PopupPanel}},
Path=ActualWidth, Converter={StaticResource PercentToDoubleConverter}, ConverterParameter=.5}" />
<Setter Property="Height" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type localControls:PopupPanel}},
Path=ActualHeight, Converter={StaticResource PercentToDoubleConverter}, ConverterParameter=.4}" />
<!--<Setter Property="localControls:PopupPanel.PopupEnterKeyCommand" Value="{Binding Path=SaveCommand}" />-->
<Setter Property="localControls:PopupPanel.PopupEscapeKeyCommand" Value="{Binding Path=CancelCommand}" />
<Setter Property="Header" Value="{Binding Path=Header}" />
<Setter Property="localControls:PopupPanel.BackgroundOpacity" Value="0" />
<Setter Property="Content">
<Setter.Value>
<localControls:LookupDialog
DataContext="{Binding}"
BorderBrush="{StaticResource DarkColor}" />
</Setter.Value>
</Setter>
</Style>
<!-- Base Style for a Popup (DraggablePanel) -->
<Style x:Key="GenericPopupStyle" TargetType="{x:Type localControls:DraggablePanel}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type localControls:DraggablePanel}">
<Border Height="{TemplateBinding Height}" Width="{TemplateBinding Width}">
<DockPanel>
<!-- Header -->
<Border
DockPanel.Dock="Top"
MinHeight="20"
Background="{DynamicResource TabItem_BackgroundBrush_Unselected}"
BorderBrush="{StaticResource DarkColor}"
BorderThickness="1"
CornerRadius="5,5,0,0"
Padding="2,3,2,2"
SnapsToDevicePixels="True"
>
<ContentPresenter x:Name="PART_DraggablePanelHeader" ContentSource="Header" />
</Border>
<!-- Content -->
<Border Background="{StaticResource DefaultBackground}"
BorderBrush="{StaticResource DarkColor}"
BorderThickness="1,0,1,1"
SnapsToDevicePixels="True">
<ContentPresenter ContentSource="Content" />
</Border>
</DockPanel>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
实用的样式：
<!-- Example Popup Style for a Panel -->
<Style x:Key="AgentDesktop_NotesPanelPopupStyle" TargetType="{x:Type ContentControl}">
<Setter Property="Canvas.Left" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type localControls:PopupPanel}},
Path=ActualWidth, Converter={StaticResource PercentToDoubleConverter}, ConverterParameter=.2}" />
<Setter Property="Canvas.Top" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type localControls:PopupPanel}},
Path=ActualHeight, Converter={StaticResource PercentToDoubleConverter}, ConverterParameter=.32}" />
<Setter Property="Width" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type localControls:PopupPanel}},
Path=ActualWidth, Converter={StaticResource PercentToDoubleConverter}, ConverterParameter=.6}" />
<Setter Property="Height" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type localControls:PopupPanel}},
Path=ActualHeight, Converter={StaticResource PercentToDoubleConverter}, ConverterParameter=.36}" />
<Setter Property="localControls:PopupPanel.PopupEnterKeyCommand" Value="{Binding Path=SaveCommand}" />
<Setter Property="localControls:PopupPanel.PopupEscapeKeyCommand" Value="{Binding Path=HidePopupCommand}" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<!-- Control Template removed to make this easier to read, but it's created from standard WPF controls with nothing special -->
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>