XamlDatProvider error

[Art Kedzierski]

Getting an odd error I can't run to ground when binding a RichTextBox to a database via MVVM. here's my simple code:

<Grid x:Name="LayoutRoot"
        Margin=" 10">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="300"/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>
    <telerik:RadListBox x:Name="ToC"
                            ItemsSource="{Binding HelpDocs}"
                            SelectedItem="{Binding SelectedTopic, Mode=TwoWay}"/>
    <telerik:XamlDataProvider x:Name="CurrentDocument"
                                RichTextBox="{Binding SelectedTopic.Body}"
                                Xaml="{Binding SelectedTopic.Body, Mode=TwoWay}"/>
    <telerik:RadRichTextBox x:Name="HelpPane"
                            Grid.Column="1"
                            LayoutMode="Flow"
                            IsReadOnly="False"
                            IsSpellCheckingEnabled="False"
                            ScrollViewer.VerticalScrollBarVisibility="Auto"
                            Background="{x:Null}"
                            BorderBrush="{x:Null}"
                            BorderThickness="0"
                            Grid.ColumnSpan="2"/>
</Grid>

The RichTextBox binding of the XamlDataProvider throws the following error:

The local property "RichTextBox" can only be applied to types that are derived from "DataProviderBase".

What am I missing?

[Iva Toteva]

Hi Art,

It seems that the problem is with the way you have set the RichTextBox property of XamlDataProvider:

RichTextBox="{Binding SelectedTopic.Body}"

Judging from the rest of the code, this SelectedTopic.Body must be the property that keeps the content of the document as a XAML string. The RichTextBox property, however, is the link between the provider and the RadRichTextBox, so it should be bound to the RadRichTextBox instance like this:

RichTextBox="{Binding ElementName="HelpPane"}"

More information on data providers can be found here.


Regards,
Iva Toteva
Telerik