Run-time error: InverseBooleanConverter not found

Question

I have a problem attempting to follow the advice in: How to bind inverse boolean properties in WPF?

When I use with ResourceDictionary, it give run-time error. InverseBooleanConverter not found.

XMAL as follows:

<UserControl x:Class="SMTF.MasterDataView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:SMTF" mc:Ignorable="d" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" d:DesignHeight="466" d:DesignWidth="483">
<UserControl.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="../AppResource.xaml" />
            <ResourceDictionary Source="../DefaultStyle.xaml" />
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</UserControl.Resources>
    <Grid>
    <StackPanel  HorizontalAlignment="Left" Margin="200,12,0,0" Name="stkMain" VerticalAlignment="Top" >
        <Grid Margin="4">
            <ContentControl Visibility="{Binding IsChecked, ElementName=VisibilityToggle, Converter={StaticResource InverseBooleanConverter}}" >
                <Border Grid.Column="2" Style="{StaticResource MainBorderStyle}">
                    <HeaderedContentControl   Content="{Binding Path=WorkspaceView}" ContentTemplate="{StaticResource WorkspacesTemplate}" Header="View" Style="{StaticResource MainHCCStyle}"/>
                </Border>
            </ContentControl>
        </Grid>
        <Grid DockPanel.Dock="Bottom" Margin="0,2,4,2">
            <TextBlock HorizontalAlignment="Right">

               <ToggleButton  x:Name="VisibilityToggle" Focusable="False" Style="{StaticResource SMToggle}"  Command ="{Binding ShowNew}" >

                </ToggleButton>
               <!--<ToggleButton x:Name="VisibilityToggle"   Background="Transparent" Command ="{Binding ShowNew}" >
                     <Image Source="/Image/Add.png"  Width="24" />
                </ToggleButton>-->
            </TextBlock>

        </Grid>

        <Grid Margin="4">
            <ContentControl Visibility="{Binding IsChecked, ElementName=VisibilityToggle, Converter={StaticResource BoolToVisibility}}" >
            <Border Grid.Column="2" Style="{StaticResource MainBorderStyle}">
                <HeaderedContentControl  Content="{Binding Path=WorkspaceEdit}" ContentTemplate="{StaticResource WorkspacesTemplate}" Header="Configure" Style="{StaticResource MainHCCStyle}"/>
            </Border>
            </ContentControl>
        </Grid>
    </StackPanel>

</Grid>
</UserControl>

I'm using the same code provided in the link. ie:

[ValueConversion(typeof(bool), typeof(bool))]
public class InverseBooleanConverter: IValueConverter
{
    #region IValueConverter Members

    public object Convert(object value, Type targetType, object parameter,
        System.Globalization.CultureInfo culture)
    {
        if (targetType != typeof(bool))
            throw new InvalidOperationException("The target must be a boolean");

        return !(bool)value;
    }

    public object ConvertBack(object value, Type targetType, object parameter,
        System.Globalization.CultureInfo culture)
    {
        throw new NotSupportedException();
    }

    #endregion
}

in the AppResource XML

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                xmlns:vm="clr-namespace:SMTF">
 <vm:InverseBooleanConverter x:Key="InverseBoolToVisibility" /> 
 .....
 .....
</ResourceDictionary>

Thanks in advance NS

pls share the code/xaml that you have tried. How you are defning the converter and how you are referencing it — Nitin, Oct 15 '13 at 07:30

score 5 · Answer 1 · answered Nov 23 '14 at 00:28

An alternative to converters for style related binding is to use Style.Triggers, the following shows a canvas when checkbox IsChecked = false, which would otherwise require an InverseBooleanConverter.

<Canvas x:Name="Overlay">
    <Canvas.Style>
        <Style TargetType="Canvas">
            <Style.Triggers>
                <DataTrigger Binding="{Binding IsChecked, ElementName=MyCheckbox}" Value="True">
                    <Setter Property="Visibility" Value="Collapsed" />
                </DataTrigger>
                <DataTrigger Binding="{Binding IsChecked, ElementName=MyCheckbox}" Value="False">
                    <Setter Property="Visibility" Value="Visible" />
                </DataTrigger>                                
            </Style.Triggers>
        </Style>
    </Canvas.Style>
    <Rectangle Canvas.ZIndex="3" Fill="#99333333" Height="25" Stroke="Transparent" Width="293" Canvas.Left="10" Canvas.Top="-25"/>
</Canvas>

I was looking for an xaml only solution and this was it! – dvdhns Jul 30 '19 at 20:58 — dvdhns, Jul 30 '19 at 20:58

Nitin · Accepted Answer · 2013-10-15T08:45:53.487

The key you are using is not correct. You resource key is InverseBoolToVisibility, while you have used InverseBooleanConverter as key.

Change the resource key to refer to correct resource as

<ContentControl Visibility="{Binding IsChecked, ElementName=VisibilityToggle, Converter={StaticResource InverseBoolToVisibility}}" >

Also your implementation for convereter is wrong. If you want to change the Visibility based on Boolean inverse value update your converter code as:

public class InverseBooleanConverter: IValueConverter
{
    #region IValueConverter Members

    public object Convert(object value, Type targetType, object parameter,
        System.Globalization.CultureInfo culture)
    {
        if (targetType != typeof(Visibility))
            throw new InvalidOperationException("The target must be a boolean");

        if(!(bool)value)
        {
            return Visibility.Visible;
        }
        return Visibility.Collapsed;
    }

    public object ConvertBack(object value, Type targetType, object parameter,
        System.Globalization.CultureInfo culture)
    {
        throw new NotSupportedException();
    }

    #endregion
}

thanks. Is there anything wrong with converter class? or any addtional code I have to use? I'm getting the targetType not boolean error! — SNS, Oct 15 '13 at 08:40
and what if the xaml of the answer is in a usercontrol and the convert in the mainWindowViewModel? How can one see the other? II tried with ancestor type, but it doesn't work — Piero Alberto, Sep 23 '14 at 14:13

Run-time error: InverseBooleanConverter not found

2 Answers2