Value is not a hop source in the route.

Hello, I have a problem with the following XAML code:

<TreeView x:Name="SettingsTree" BorderThickness="0"> <TreeView.Resources> <SolidColorBrush Color="Transparent" x:Key="{x:Static SystemColors.HighlightBrushKey}"/> </TreeView.Resources> <TreeViewItem Header="???" IsExpanded="True"> <Grid Margin="-20,0,0,0"> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto"/> <ColumnDefinition Width="*"/> </Grid.ColumnDefinitions>

            <TextBlock Name="Range" Grid.Column="0" Text="{lex:Loc Range}" Style="{StaticResource TextBlock.PropertyEditor}"/>
            <TextBox Grid.Column="1" Text="{Binding BasicInstrumentSetting.Range,UpdateSourceTrigger=LostFocus}" ToolTip="{lex:Loc Voltage.ToolTip}" Style="{StaticResource TextBox.PropertyEditor}"
                     cal:Message.Attach="[Event GotKeyboardFocus] = [Action GotKeyboardFocus(Range.Text,$this.ToolTip)]"/>
        </Grid>
    </TreeViewItem>
</TreeView>

StackTrace Image:

My application crash with this code!!! But If I cancel in this row <TreeViewItem Header="???" IsExpanded="True"> -> IsExpanded=“True” In this way my application works.

Can I have any suggestions???

Regards, Bernardo

[mittal-kkr]

if you pass any parameter without “$”, then this problem occurs.

[arcuri]

Thank you very much!!!