I'm trying to bind the tooltip of a ListBoxItem. I have this defined in my ControlTemplate: ``` <Image x:Name="imgFullSize" DockPanel.Dock="Top" Stre…

Eventually solved this by changing the tooltip to this: ``` ... ... ``` Thanks @Rachel for leading me to the answer.

WPF DataContext in ToolTip

binding, data-binding, datacontext, tooltip, wpf

Solution

Eventually solved this by changing the tooltip to this:

...
<Border.ToolTip>
    <ToolTip DataContext="{Binding PlacementTarget.DataContext.Images, RelativeSource={RelativeSource Self}}" Visibility="{Binding PlacementTarget.DataContext.Images, RelativeSource={RelativeSource Self},Converter={StaticResource FirstImageConverter},ConverterParameter=visible}">
        <DockPanel LastChildFill="True" Margin="2" MaxWidth="800">
            ...

Thanks @Rachel for leading me to the answer.

Problem

I'm trying to bind the tooltip of a ListBoxItem. I have this defined in my ControlTemplate: ``` <ControlTemplate TargetType="{x:Type ListBoxItem}"> <ControlTemplate.Resources> <conv:IconConverter x:Key="IconConverter" /> <conv:FirstImageConverter x:Key="FirstImageConverter"/> <conv:DebugConverter x:Key="dbg"/> </ControlTemplate.Resources> <Border ...> <StackPanel> <Image MaxHeight="160" Stretch="UniformToFill" Source="{Binding Icon,Converter={StaticResource IconConverter},ConverterParameter=128}" Height="128"/> <TextBlock x:Name="lblName" Text="{Binding Name}" /> </StackPanel> <Border.ToolTip> <DockPanel LastChildFill="True" Margin="2" MaxWidth="800" DataContext="{Binding Images,Converter={StaticResource FirstImageConverter}}" IsEnabled="{Binding Images,Converter={StaticResource FirstImageConverter},ConverterParameter=enabled}"> <TextBlock DockPanel.Dock="Bottom" Width="Auto" MaxWidth="600" Text="{Binding Caption}" Height="Auto" /> <Image x:Name="imgFullSize" DockPanel.Dock="Top" Stretch="None" Width="Auto" Source="{Binding Filename,Converter={StaticResource IconConverter}}"/> </DockPanel> </Border.ToolTip> ``` Yes I get a binding error: `System.Windows.Data Error: 3 : Cannot find element that provides DataContext. BindingExpression:Path=Images; DataItem=null; target element is 'DockPanel' (Name=''); target property is 'DataContext' (type 'Object')` My ListBoxItem's datacontext does contain the images property as it does the name and icon properties, which are displayed correctly. I've also tried using `TooltipService.ToolTip` instead of `Border.ToolTip`, with no effect. What's the difference, and why isn't my binding working?

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