我正在Expression Blend 4中製作一個Silverlight應用程序的原型,並且我試圖根據它們綁定到的數據中的布爾值來顯示/隱藏ListBox/ComboBox項目。我發現這表明這會工作示例在線,但它並不:Silverlight ListboxItem可見性綁定
<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:ed="http://schemas.microsoft.com/expression/2010/drawing"
xmlns:local="clr-namespace:PrototypeScreens"
mc:Ignorable="d"
x:Class="PrototypeScreens.Toolbar"
Width="640" Height="31">
<UserControl.Resources>
<local:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" />
</UserControl.Resources>
<Grid x:Name="LayoutRoot" Background="White">
<ComboBox HorizontalAlignment="Right" Style="{StaticResource ComboBox-Sketch}" VerticalAlignment="Top" Width="32" ItemsSource="{Binding Sites}" >
<ComboBox.ItemTemplate>
<DataTemplate>
<Grid>
<ed:RegularPolygon Fill="{StaticResource BaseBackground-Sketch}" ed:GeometryEffect.GeometryEffect="Sketch" HorizontalAlignment="Left" Height="10" InnerRadius="0.47211" Margin="0,0,0,0" PointCount="5" Stretch="Fill" Stroke="{StaticResource BaseBorder-Sketch}" StrokeThickness="2" UseLayoutRounding="False" Width="10"
Visibility="{Binding IsFavorite, Converter={StaticResource BooleanToVisibilityConverter}}" />
<TextBlock Style="{StaticResource BasicTextBlock-Sketch}" Text="{Binding Name}" HorizontalAlignment="Left" Margin="15,0,0,0" />
</Grid>
</DataTemplate>
</ComboBox.ItemTemplate>
<!--
<ComboBox.ItemContainerStyle>
<Style TargetType="ComboBoxItem">
<Setter Property="Visibility" Value="{Binding IsRegistered, Converter={StaticResource BooleanToVisibilityConverter}}" />
</Style>
</ComboBox.ItemContainerStyle>
-->
</ComboBox>
<ListBox Height="29" Margin="0,0,32,0" Style="{StaticResource ListBox-Sketch}" VerticalAlignment="Top" ItemsSource="{Binding Sites}" ScrollViewer.HorizontalScrollBarVisibility="Hidden">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" FlowDirection="RightToLeft" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<TextBlock Style="{StaticResource BasicTextBlock-Sketch}" Text="{Binding Id}" HorizontalAlignment="Left" Margin="0,0,0,0" />
<ed:RegularPolygon Fill="{StaticResource BaseBackground-Sketch}" ed:GeometryEffect.GeometryEffect="Sketch" HorizontalAlignment="Left" Height="10" InnerRadius="0.47211" Margin="20,0,0,0" PointCount="5" Stretch="Fill" Stroke="{StaticResource BaseBorder-Sketch}" StrokeThickness="2" UseLayoutRounding="False" Width="10"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
<!--
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="Visibility" Value="{Binding IsFavorite, Converter={StaticResource BooleanToVisibilityConverter}}" />
</Style>
</ListBox.ItemContainerStyle>
-->
</ListBox>
</Grid>
</UserControl>
當我嘗試這個用戶控件加載屏幕,應用程序崩潰,除非我註釋掉容器樣式(如上面的代碼)。我究竟做錯了什麼?
注意: ComboBoxItem內的多邊形的可見性工作正常。
UPDATE我包括XAML整個用戶控件
UPDATE我得到了一些錯誤的詳細信息:
Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; MDDC; .NET4.0C; .NET4.0E; BRI/2)
Timestamp: Tue, 10 May 2011 15:21:02 UTC
Message: Unhandled Error in Silverlight Application Exception has been thrown by the target of an invocation. at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache)
at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Reflection.Assembly.CreateInstance(String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at Microsoft.Expression.Prototyping.Workspace.PlayerWindow.InstantiateScreen(String screen, Boolean showImmediately)
at Microsoft.Expression.Prototyping.Workspace.PlayerWindow.TransitionScreens(String from, String to)
at Microsoft.Expression.Prototyping.Navigation.NavigationViewModel.NavigateToScreen(String name, Boolean record)
Line: 1
Char: 1
Code: 0
URI: file:///D:/Projects/Expression/Prototype/Bin/Debug/Default.html
更新:我覺得我取得了一些進展。看起來綁定無法解析。列表框和組合框都有ItemsSource="{Binding Sites}"
和Sites
類型爲System.Collections.ObjectModel.ObservableCollection<SitesItem>
。 SiteItem
有屬性IsRegistered
和IsFavorite
。
所以我想問題是:是否有可能綁定到IsRegistered
和IsFavorite
在ItemContainerStyle
?
你在哪裏設置你的'BooleanToVisibilityConverter'靜態資源:所以,簡單地如下定義的呢?可能是因爲它沒有在樣式應用之前創建。你能提供墜機的細節嗎? – 2011-05-10 14:07:49
我確實定義了'BooleanToVisibilityConverter'。 – 2011-05-10 14:28:14
雖然它可能是一個訂單問題。如果在應用樣式時未創建轉換器,則可能有問題。如果你能按照什麼順序完成工作,可能值得一看。 – 2011-05-10 15:10:47