"System.Windows.Data Errore: 4" in un MenuItem dinamico

Question

Ho un MenuControl WPF a cui aggiungo diverse voci di menu in fase di esecuzione. Se sei interessato a conoscere, la ragione è che leggiamo i dati da un database e abbiamo bisogno di creare i MenuItem in base ai dati restituiti. Abbiamo quello che direi uno stile di menu complesso (almeno complesso da leggere :)). Ora, quando aggiungo le mie voci di menu continuo a ricevere questo errore nella finestra Debug di Visual Studio:

System.Windows.Data Error: 4 : Cannot find source for binding with reference  'RelativeSource FindAncestor, AncestorType='System.Windows.Controls.ItemsControl', AncestorLevel='1''. BindingExpression:Path=HorizontalContentAlignment; DataItem=null; target element is 'MenuItem' (Name=''); target property is 'HorizontalContentAlignment' (type 'HorizontalAlignment') 

System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='System.Windows.Controls.ItemsControl', AncestorLevel='1''. BindingExpression:Path=VerticalContentAlignment; DataItem=null; target element is 'MenuItem' (Name=''); target property is 'VerticalContentAlignment' (type 'VerticalAlignment') 

quelle due ripetere più volte Credo che in base al numero di MenuItems aggiunto. L'altro comportamento strano che ho notato è che, dopo che questi errori si sono verificati nella finestra di debug, MenuControl si chiude (si apre) da solo, semplicemente spostando il mouse su di esso (non facendo clic su di esso come normalmente fatto). Quindi, immagino che uno abbia a che fare con l'altro.

Qualche idea su cosa sta succedendo ?? Il MenuControlCode è piuttosto lungo ma, se necessario, posso anche pubblicarlo.

Questo è il codice XAML di MenuControl. Dopo di che, nel codice mi basta usare il "PrincipalMenu" e aggiungi MenuItems ad esso come necessario:

<UserControl x:Class="EOGMapControl.MainPropertyGUI.MenuControl" 
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
     mc:Ignorable="d" 
     d:DesignHeight="41" d:DesignWidth="380"> 
<UserControl.Resources> 
    <SolidColorBrush x:Key="HighlightedBackgroundBrush" Color="#FFDEDEDE" /> 
    <SolidColorBrush x:Key="MenuBackgroundBrush" Color="White" /> 
    <SolidColorBrush x:Key="NormalBorderBrush" Color="#FFE5DFDF" /> 
    <SolidColorBrush x:Key="SolidMenuFontBrush" Color="Black" /> 
    <SolidColorBrush x:Key="HighlightedText" Color="White" /> 
    <SolidColorBrush x:Key="menuItemBrush" Color="#FFB7B7B7" /> 
    <SolidColorBrush x:Key="WindowBackgroundBrush" Color="#FFF" /> 
    <SolidColorBrush x:Key="SolidBorderBrush" Color="#888" /> 
    <Style x:Key="{x:Type Menu}" TargetType="{x:Type Menu}"> 
     <Setter Property="OverridesDefaultStyle" Value="True"/> 
     <Setter Property="SnapsToDevicePixels" Value="True"/> 
     <Setter Property="Height" Value="25"/> 
     <Setter Property="Foreground" Value="{StaticResource SolidMenuFontBrush}"/> 
     <Setter Property="Template"> 
      <Setter.Value> 
       <ControlTemplate TargetType="{x:Type Menu}"> 
        <Border 
     Background="{StaticResource MenuBackgroundBrush}" 
     BorderBrush="{StaticResource MenuBackgroundBrush}" 
     BorderThickness="1"> 
         <StackPanel ClipToBounds="True" Orientation="Horizontal" IsItemsHost="True"/> 
        </Border> 

       </ControlTemplate> 
      </Setter.Value> 
     </Setter> 
    </Style> 
    <Style x:Key="{x:Type MenuItem}" TargetType="{x:Type MenuItem}"> 
     <Setter Property="Template"> 
      <Setter.Value> 
       <ControlTemplate TargetType="{x:Type MenuItem}"> 
        <Border x:Name="Border" 
       Background="{TemplateBinding Background}" 
       BorderBrush="{TemplateBinding BorderBrush}" 
       BorderThickness="0"> 
         <Grid> 
          <Grid.ColumnDefinitions> 
           <ColumnDefinition x:Name="Col0" MinWidth="17" Width="Auto" SharedSizeGroup="MenuItemIconColumnGroup"/> 
           <ColumnDefinition Width="Auto" SharedSizeGroup="MenuTextColumnGroup"/> 
           <ColumnDefinition Width="Auto" SharedSizeGroup="MenuItemIGTColumnGroup"/> 
           <ColumnDefinition x:Name="Col3" Width="14"/> 
          </Grid.ColumnDefinitions> 

          <!-- ContentPresenter to show an Icon if needed --> 
          <ContentPresenter Grid.Column="0" Margin="4,0,6,0" x:Name="Icon" VerticalAlignment="Center" ContentSource="Icon"/> 

          <!-- Glyph is a checkmark if needed for a checkable menu --> 
          <Grid Grid.Column="0" Visibility="Hidden" Margin="4,0,6,0" x:Name="GlyphPanel" VerticalAlignment="Center"> 
           <Path x:Name="GlyphPanelpath" VerticalAlignment="Center" Fill="{TemplateBinding Foreground}" Data="M0,2 L0,4.8 L2.5,7.4 L7.1,2.8 L7.1,0 L2.5,4.6 z" FlowDirection="LeftToRight"/> 
          </Grid> 

          <!-- Content for the menu text etc --> 
          <ContentPresenter Grid.Column="1" 
          Margin="{TemplateBinding Padding}" 
          x:Name="HeaderHost" 
          RecognizesAccessKey="True" 
          ContentSource="Header"/> 

          <!-- Content for the menu IGT --> 
          <ContentPresenter Grid.Column="2" 
          Margin="8,1,8,1" 
          x:Name="IGTHost" 
          ContentSource="InputGestureText" 
          VerticalAlignment="Center"/> 

          <!-- Arrow drawn path which points to the next level of the menu --> 
          <Grid Grid.Column="3" Margin="4,0,6,0" x:Name="ArrowPanel" VerticalAlignment="Center"> 
           <Path x:Name="ArrowPanelPath" HorizontalAlignment="Right" VerticalAlignment="Center" Fill="{TemplateBinding Foreground}" Data="M0,0 L0,8 L4,4 z"/> 
          </Grid> 
          <!--IsOpen="{Binding Path=IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}" 
          PopupAnimation="{DynamicResource {x:Static SystemParameters.MenuPopupAnimationKey}}" 
          --> 
          <!-- The Popup is the body of the menu which expands down or across depending on the level of the item --> 
          <Popup Placement="Right" IsOpen="{TemplateBinding IsSubmenuOpen}" x:Name="SubMenuPopup" Focusable="false" PopupAnimation="Fade"> 
           <Border x:Name="SubMenuBorder" SnapsToDevicePixels="True" Background="{StaticResource WindowBackgroundBrush}" BorderBrush="{StaticResource SolidBorderBrush}" BorderThickness="1" Padding="2,2,2,2"> 
            <Grid x:Name="SubMenu" Grid.IsSharedSizeScope="True"> 
             <!--StackPanel holds children of the menu. This is set by IsItemsHost=True--> 
             <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Cycle"/> 
             <!--<ScrollViewer CanContentScroll="True"> 
              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Cycle" /> 
             </ScrollViewer>--> 
            </Grid> 
           </Border> 
          </Popup> 
         </Grid> 
        </Border> 

        <!-- These triggers re-configure the four arrangements of MenuItem to show different levels of menu via Role --> 
        <ControlTemplate.Triggers> 

         <!-- Role = TopLevelItem : this is a child menu item from the top level without any child items--> 
         <Trigger Property="Role" Value="TopLevelItem"> 
          <Setter Property="Padding" Value="6,1,6,1"/> 
          <Setter Property="Visibility" Value="Collapsed" TargetName="ArrowPanel"/> 
         </Trigger> 

         <!-- Role = SubMenuHeader : this is a child menu item which does not have children --> 
         <Trigger Property="Role" Value="SubmenuHeader"> 
          <Setter Property="DockPanel.Dock" Value="Top"/> 
          <Setter Property="Padding" Value="0,2,0,2"/> 
         </Trigger> 

         <!-- Role = SubMenuItem : this is a child menu item which has children--> 
         <Trigger Property="Role" Value="SubmenuItem"> 
          <Setter Property="DockPanel.Dock" Value="Top"/> 
          <Setter Property="Padding" Value="0,2,0,2"/> 
          <Setter Property="Visibility" Value="Collapsed" TargetName="ArrowPanel"/> 
         </Trigger> 

         <Trigger Property="IsSuspendingPopupAnimation" Value="true"> 
          <Setter Property="PopupAnimation" Value="None" TargetName="SubMenuPopup"/> 
         </Trigger> 

         <!-- If no Icon is present the we collapse the Icon Content --> 
         <Trigger Property="Icon" Value="{x:Null}"> 
          <Setter Property="Visibility" Value="Collapsed" TargetName="Icon"/> 
         </Trigger> 

         <!-- The GlyphPanel contains the CheckMark --> 
         <Trigger Property="IsChecked" Value="true"> 
          <Setter Property="Visibility" Value="Visible" TargetName="GlyphPanel"/> 
          <Setter Property="Visibility" Value="Collapsed" TargetName="Icon"/> 
         </Trigger> 

         <!-- Using the system colors for the Menu Highlight and IsEnabled--> 
         <Trigger Property="IsHighlighted" Value="true"> 
          <Setter Property="Background" Value="{StaticResource HighlightedBackgroundBrush}" TargetName="Border"/> 
          <Setter Property="Foreground" Value="{StaticResource HighlightedText}"/> 
          <Setter Property="BorderBrush" Value="{StaticResource NormalBorderBrush}" TargetName="Border"/> 
         </Trigger> 
         <Trigger Property="IsHighlighted" Value="false"> 
          <Setter Property="Background" Value="{StaticResource MenuBackgroundBrush}" TargetName="Border"/> 
          <Setter Property="Foreground" Value="{StaticResource SolidMenuFontBrush}"/> 
          <Setter Property="BorderBrush" Value="{StaticResource MenuBackgroundBrush}" TargetName="Border"/> 
         </Trigger> 
         <Trigger Property="IsEnabled" Value="false"> 
          <Setter Property="Foreground" Value="LightGray"/> 
         </Trigger> 
        </ControlTemplate.Triggers> 
       </ControlTemplate> 
      </Setter.Value> 
     </Setter> 
    </Style> 
</UserControl.Resources> 
<UserControl.Foreground> 
    <SolidColorBrush /> 
</UserControl.Foreground> 
<Grid Height="24" Width="250" HorizontalAlignment="Left"> 
    <Grid.Background> 
     <SolidColorBrush /> 
    </Grid.Background> 
    <Menu Name="PrincipalMenu" Margin="0,0,-100,0"> 
    </Menu> 
</Grid> 

Answer 1

riferiscono gentile il collegamento sotto:

http://www.codeproject.com/Tips/124556/How-to-suppress-the-System-Windows-Data-Error-warn

La soluzione è , imposta il livello dell'interruttore di origine del binding dei dati come critico nel costruttore della classe.

public TestSample() //constructor of the class 
{ 
    InitializeComponent(); 

    System.Diagnostics.PresentationTraceSources.DataBindingSource.Switch.Level = System.Diagnostics.SourceLevels.Critical; 

}