2011-05-10 93 views
1

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}"Sites類型爲System.Collections.ObjectModel.ObservableCollection<SitesItem>SiteItem有屬性IsRegisteredIsFavorite

所以我想問題是:是否有可能綁定到IsRegisteredIsFavoriteItemContainerStyle

+1

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

+0

我確實定義了'BooleanToVisibilityConverter'。 – 2011-05-10 14:28:14

+0

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

回答

0

WPF已經帶有一個開箱即用的BooleanToVisibilityConverter。

<UserControl.Resources> 
    <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/> 
</UserControl.Resources> 

希望這有助於