How to set a DynamicResource as PriorityBinding? - wpf

Question

I have a multilanguage application which contains two dictionary en.xaml and it.xaml, suppose that I have the following situation:
I need to display a default text in a TextBlock such as: Contact saved 0 in memory using a DynamicResource key that contains the text above.
Unfortunately xaml doesn't allow to use DynamicResource in a StringFormat or as FallbackValue so I used this code:
<TextBlock Tag="{DynamicResource defaultContactStr}">
<TextBlock.Text>
<PriorityBinding>
<Binding Path="ContactSaved" />
<Binding Path="Tag" RelativeSource="{RelativeSource Mode=Self}" />
</PriorityBinding>
</TextBlock.Text>
this will display only 0 which is the default value of the proeprty ContactSaved, but I need to display: Contact saved 0 in memory, or if the value change: Contact saved 5 in memory etc...
how can I manage this situation?

Answer 1

Using a StringFormat works only if the format (the translation in your case) is known at compile-time:
<TextBlock>
<TextBlock.Text>
<Binding Path="ContactSaved" StringFormat="{}Contact saved {0} in memory" />
</TextBlock.Text>
</TextBlock>
Othwerwise you may handle this using a converter and a MultiBinding:
public class CustomConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
string resource = values[0] as string;
string contactSaved = values[1].ToString();
return string.Format(resource, contactSaved);
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
XAML:
<TextBlock Tag="{DynamicResource defaultContactStr}">
<TextBlock.Text>
<MultiBinding>
<MultiBinding.Converter>
<local:CustomConverter />
</MultiBinding.Converter>
<Binding Path="Tag" RelativeSource="{RelativeSource Mode=Self}" />
<Binding Path="ContactSaved" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
en.xaml:
<system:String x:Key="defaultContactStr">Contact saved {0} in memory</system:String>
Remember that XAML is nothing but a markup language.