WPF Templates error - "Provide value on 'System.Windows.Baml2006.TypeConverterMarkupExtension' threw an exception."

Question

I've just started experimenting with WPF templates vs. styles and I'm not sure what I'm doing wrong. The goal below is to alternate the colors of the options in the menu. The code works fine with just the , but when I copy and paste/rename it for the second segment of "MenuChoiceOdd" I get the following error:

> Provide value on 'System.Windows.Baml2006.TypeConverterMarkupExtension' threw an exception.

Sample of the code:

<Window x:Class="WpfApplication1.Template_Testing"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Template_Testing" Height="300" Width="300">
    <Grid>
        <Grid.Resources>
            <ControlTemplate x:Key="MenuChoiceEven">
                <Border BorderThickness="1" BorderBrush="#FF4A5D80">
                <TextBlock Height="Auto" HorizontalAlignment="Stretch" Margin="0"  Width="Auto" FontSize="14" Foreground="SlateGray" TextAlignment="Left" AllowDrop="True" Text="{Binding Path=Content, RelativeSource={RelativeSource TemplatedParent}}">
                    <TextBlock.Background>
                        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                            <GradientStop Color="White" Offset="0" />
                            <GradientStop Color="#FFC2CCDB" Offset="1" />
                        </LinearGradientBrush>
                    </TextBlock.Background>
                </TextBlock>
                </Border>
            </ControlTemplate>
            <ControlTemplate x:Key="MenuChoiceOdd">
                <Border BorderThickness="1" BorderBrush="#FF4A5D80">
                    <TextBlock Height="Auto" HorizontalAlignment="Stretch" Margin="0"  Width="Auto" FontSize="14" Foreground="SlateGray" TextAlignment="Left" AllowDrop="True" Text="{Binding Path=Content, RelativeSource={RelativeSource TemplatedParent}}">
                    <TextBlock.Background>
                        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                            <GradientStop Color="White" Offset="0" />
                            <GradientStop Color="##FFCBCBCB" Offset="1" />
                        </LinearGradientBrush>
                    </TextBlock.Background>
                    </TextBlock>
                </Border>
            </ControlTemplate>            
        </Grid.Resources>
        <Border BorderBrush="SlateGray" BorderThickness="2" Margin="10" CornerRadius="10" Background="LightSteelBlue" Width="200">
            <StackPanel Margin="4">
                <TextBlock Height="Auto" HorizontalAlignment="Stretch" Margin="2,2,2,0" Name="MenuHeaderTextBlock" Text="TextBlock" Width="Auto" FontSize="16" Foreground="PaleGoldenrod" TextAlignment="Left" Padding="10" FontWeight="Bold"><TextBlock.Background><LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"><GradientStop Color="LightSlateGray" Offset="0" /><GradientStop Color="DarkSlateGray" Offset="1" /></LinearGradientBrush></TextBlock.Background></TextBlock>
                <StackPanel Height="Auto" HorizontalAlignment="Stretch" Margin="2,0,2,0" Name="MenuChoicesStackPanel" VerticalAlignment="Top" Width="Auto">
                    <Button Template="{StaticResource MenuChoiceEven}" Content="Test Even menu element" />
                    <Button Template="{StaticResource MenuChoiceOdd}"  Content="Test odd menu element" />
                </StackPanel>
            </StackPanel>
        </Border>
    </Grid>
</Window>

What am I doing wrong?

Answer 1

Oy it's Monday...

When I copied pasted the color string from another control it put two "##"s in the prefix here:

<GradientStop Color="##FFCBCBCB" Offset="1" />

Still a lousy error message.

Answer 2

Similarly to others - this horrific error message just meant I had a syntax error in my xaml:

<CheckBox Height="" IsChecked="{Binding IsChecked, Mode=TwoWay}"  Width="80">

Notice I hadn't filled in the height value..

Answer 3

I had the same error caused by:

<Border Margin="5" BorderBrush="Black" BorderThickness="" Width="Auto"/>

fixed by putting a number in BorderThickness

Answer 4

In my case, I changed the project name. After I got this error. I re-selected the images and saw that I needed to change the resource name of images too.

        <Image x:Name="imgSrc" Grid.Row="1" Source="/PREV%20-%20Filter;component/Images/Subtraktive%20Farbmischung%20%28Malen%20mit%20Wasserfarben%29.jpg" />

/PREV%20-%20Filter;component needs to be corrected to /DSP%20-%20Filter;component in my case.