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I got a strange issue with binding in XAML with Element Name.

Everything worked just fine but when I surrounded controls and usercontrols with a StackPanel I get a Binding Error.

I'm binding the visibility of two usercontrols with the IsChecked Property of two togglebuttons (IsDeadToggle and IsNotTransportable) and using ElementName.

<ItemsControl AlternationCount="100" FocusVisualStyle="{x:Null}" HorizontalAlignment="Left">
                        <ItemsControl.ItemsSource>
                            <CompositeCollection>
                                <StackPanel x:Name="FirstSP" Margin="0,0,10,0">
                                    <TextBlock FocusVisualStyle="{x:Null}"
                                               Style="{StaticResource WrapTitleAddTextBlock}"
                                               Text="{x:Static languages:ResCommon.General}" />
                                    <StackPanel x:Name="BuggedSP" Background="{StaticResource WrapBackground}">
                                        <StackPanel Orientation="Horizontal"
                                                    Margin="10,20">
                                            <RadioButton Content="{x:Static languages:ResCommon.Man}"
                                                         IsChecked="{Binding Path=Add.Presenter.Customer.Gender, Mode=TwoWay, Converter={StaticResource EnumMatchToBooleanConverter}, ConverterParameter=Male}" />
                                            <RadioButton x:Name="IsWoman"
                                                         Content="{x:Static languages:ResCommon.Woman}"
                                                         IsChecked="{Binding Path=Add.Presenter.Customer.Gender,
                                                                             Mode=TwoWay,
                                                                             Converter={StaticResource EnumMatchToBooleanConverter},
                                                                             ConverterParameter=Female}" />
                                        </StackPanel>
                                        <formElement:LabelComboBox Margin="{StaticResource ControlAddMargin}"
                                                                   Visibility="{Binding Add.Presenter.Customer.CustomerIdInsured, Converter={StaticResource NullToVisibilityConverter}}"
                                                                   LabelName="{x:Static languages:ResCommon.BeneficiaryType}"
                                                                   ComboBoxDisplayMemberItem="Translation"
                                                                   ComboBoxSelectedValueItem="Enum"
                                                                   ComboBoxItems="{Binding Source={me:EnumValues EnumType=entities:TypeOfBeneficiary, ResourceName='Languages.ResEnum,Languages'}}"
                                                                   ComboBoxSelectedItem="{Binding Add.Presenter.Customer.TypeOfBeneficiary}" />
                                        <formElement:InnerLabelBox Margin="{StaticResource ControlAddMargin}"
                                                                   LabelName="{x:Static languages:ResCommon.LastName}"
                                                                   TextBoxValue="{Binding Add.Presenter.Customer.LastName,
                                                                                 Converter={StaticResource StringToUpperStringConverter},
                                                                                 Mode=TwoWay,
                                                                                 ValidatesOnDataErrors=true,
                                                                                 NotifyOnValidationError=true}" />
                                        <formElement:LabelBox Margin="{StaticResource ControlAddMargin}"
                                                              LabelName="{x:Static languages:ResCommon.MaidenName}"
                                                              TextBoxValue="{Binding Add.Presenter.Customer.MaidenName,
                                                                                 Converter={StaticResource StringToUpperStringConverter},
                                                                                 Mode=TwoWay,
                                                                                 ValidatesOnDataErrors=true,
                                                                                 NotifyOnValidationError=true}"
                                                              Visibility="{Binding IsChecked,
                                                                               ElementName=IsWoman,
                                                                               Converter={StaticResource BooleanToVisibilityConverter}}" />
                                        <formElement:InnerLabelBox Margin="{StaticResource ControlAddMargin}"
                                                                   LabelName="{x:Static languages:ResCommon.FirstName}"
                                                                   TextBoxValue="{Binding Add.Presenter.Customer.FirstName,
                                                                                 Converter={StaticResource StringToCapitalizeStringConverter},
                                                                                 Mode=TwoWay,
                                                                                 ValidatesOnDataErrors=true,
                                                                                 NotifyOnValidationError=true}" />
                                        <resources:DateTimePickerTextBoxSwitch
                                            Margin="{StaticResource ControlAddMargin}"
                                            TextBoxValue="{Binding Add.Presenter.Customer.BirthDateCustom,
                                                                                Mode=TwoWay,
                                                                                ValidatesOnDataErrors=true,
                                                                                NotifyOnValidationError=true}"
                                            DateTimeValue="{Binding Add.Presenter.Customer.BirthDate, Mode=TwoWay}" />
                                        <Grid Width="220" Margin="10,10,10,0">
                                            <Grid.ColumnDefinitions>
                                                <ColumnDefinition Width="*"></ColumnDefinition>
                                                <ColumnDefinition Width="60"></ColumnDefinition>
                                            </Grid.ColumnDefinitions>
                                            <TextBlock Style="{StaticResource DarkSmallFontStyle}" Text="{x:Static languages:ResCustomers.IsDead}"></TextBlock>
                                            <ToggleButton Grid.Column="1" IsChecked="{Binding Add.Presenter.Customer.IsAlive, Mode=TwoWay}"
                                                          Style="{StaticResource OnOffToggleButton}"
                                                          x:Name="IsDeadToggle" />
                                        </Grid>
                                        <formElement:LabelDatePicker Margin="{StaticResource ControlAddMargin}"
                                                                     DatePickerValue="{Binding Add.Presenter.Customer.DeathDate,
                                                                                           Mode=TwoWay}"
                                                                     LabelName="{x:Static languages:ResCustomers.DeathDate}"
                                                                     Visibility="{Binding IsChecked,
                                                                                      ElementName=IsDeadToggle,
                                                                                      Converter={StaticResource BooleanToVisibilityConverterCustomInvert}}"
                                                                     PrintEnum="WithDate" />
                                        <Grid Width="220" Margin="10,10,10,0">
                                            <Grid.ColumnDefinitions>
                                                <ColumnDefinition Width="*"></ColumnDefinition>
                                                <ColumnDefinition Width="60"></ColumnDefinition>
                                            </Grid.ColumnDefinitions>
                                            <TextBlock Style="{StaticResource DarkSmallFontStyle}" Text="{x:Static languages:ResCustomers.IsNoTransportable}"></TextBlock>
                                            <ToggleButton Grid.Column="1" IsChecked="{Binding Add.Presenter.Customer.IsNoTransportable, Mode=TwoWay}"
                                                          Style="{StaticResource OnOffToggleButton}"
                                                          x:Name="IsNotTransportableToggle" />
                                        </Grid>
                                        <formElement:MultiLineTextBox
                                            Margin="{StaticResource ControlAddMargin}"
                                            LabelName="{x:Static languages:ResCustomers.NoTransportComment}"
                                            TextBoxValue="{Binding Add.Presenter.Customer.NoTransportComment,
                                                                                         Mode=TwoWay,
                                                                                         ValidatesOnDataErrors=true,
                                                                                         NotifyOnValidationError=true}"
                                            Visibility="{Binding IsChecked,
                                                                                       ElementName=IsNotTransportableToggle,
                                                                                       Converter={StaticResource BooleanToVisibilityConverterCustom}}" />

                                    </StackPanel>
                                </StackPanel>

The added StackPanel is the one withthe following property

x:name="BuggedSP"

Error:

System.Windows.Data Error: 4 : Cannot find source for binding with reference 'ElementName=IsDeadToggle'. BindingExpression:Path=IsChecked; DataItem=null; target element is 'LabelDatePicker' (Name='UCLabelDatePicker'); target property is 'Visibility' (type 'Visibility')

EDIT 1 :

If I delete the FirstSP StackPanel it works again... I begin to think it's a depth issue. But I can't see why my binding wouldn't work at a specific depth level

EDIT 2 :

If I delete the grids surrounding the togglebuttons, it doesn't work either so it doesn't matter if the toggle is at the same level as the usercontrol.

So with that VisualTree (WPF Tree WPF Tree Visualizer) everything's just fine:

<WrapPanel>
    <ItemsControl>
        <ItemsPresenter>
            <WrapPanel>
                <StackPanel>
                    <!-- List of UC and Toggles-->

With this one it doesn't work:

<WrapPanel>
    <ItemsControl>
        <ItemsPresenter>
            <WrapPanel>
                <StackPanel>
                    <StackPanel x:Name="BuggedSp">        
                    <!-- List of UC and Toggles-->
smashit
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  • Not sure if this would make any difference but have you tried using Name instead of x:name? I have read there are some differences. – kenjara Apr 16 '14 at 16:29
  • Basically I would say that the problem is with the Visual Tree. Check this link out:http://stackoverflow.com/questions/705853/binding-elementname-does-it-use-visual-tree-or-logical-tree – sexta13 Apr 16 '14 at 16:34
  • @sexta13 The control is not inside a `DataTemplate/ControlTemplate` – 123 456 789 0 Apr 16 '14 at 17:50
  • @kenjara tried to replace x:name but didn't work – smashit Apr 17 '14 at 07:59

1 Answers1

0

I can see that your ToggleButton, IsDeadToggle, has a two way binding on the IsChecked property to the Add.Presenter.Customer.IsAlive property on your data context.

I can also see that you are trying to bind the Visibility property of your LabelDatePicker to the IsChecked property of the ToggleButton, using a converter to inverse and then convert the bool value to a System.Windows.Visibility.

Since both the ToggleButton and LabelDatePicker share the same data context, I would simply bind the visibility of the LabelDatePicker to the same property on the data context:

<formElement:LabelDatePicker
    Margin="{StaticResource ControlAddMargin}"
    DatePickerValue="{Binding Add.Presenter.Customer.DeathDate, Mode=TwoWay}"
    LabelName="{x:Static languages:ResCustomers.DeathDate}"
    Visibility="{Binding Add.Presenter.Customer.IsAlive, Converter={StaticResource BooleanToVisibilityConverterCustomInvert}}"
    PrintEnum="WithDate" />

Note: the data context (Customer object) will need to implement System.ComponentModel.INotifyPropertyChanged and the IsAlive property will need to raise the PropertyChanged event with the name of the property to ensure the LabelDatePicker is properly notified to rebind when the IsDeadToggle check box has changed its value.

See MSDN for more info: http://msdn.microsoft.com/en-us/library/system.componentmodel.inotifypropertychanged(v=vs.110).aspx

As a rule, I tend to avoid element-to-element binding in favour of a common property in the data context. This way is more testable and less brittle (as if you change the name of the source element, IsDeadToggle, then you need to remember to update the binding target).

WonkiDonk
  • 319
  • 2
  • 7
  • Thanks !! That did the trick ! I'll try to bind to props in datacontext as much as I can in the future. However, I can't understand why ElementName is not working at a specific depth level but well I agree using DataContext is easier to read anyway... – smashit Apr 24 '14 at 07:37