WPF MarkupExtension binding error - wpf

Question

refers to implementing a multilanguage interface now I have a problem. I have a grid where its ItemSource it's a Dictionary<string, string>: I can't give the key value as parameter of the markup extension because I have the following exception
A 'Binding' cannot be set on the 'Value1' property of type 'TranslateMarkupExtension'.
A 'Binding' can only be set on a DependencyProperty of a DependencyObject.
This is the xaml where I use the markup extension:
<ItemsControl ItemsSource="{Binding MyDictionary}" Grid.Row="0">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid Margin="10">
<Grid.ColumnDefinitions>
<ColumnDefinition></ColumnDefinition>
<ColumnDefinition></ColumnDefinition>
</Grid.ColumnDefinitions>
<Label Content="{TranslateMarkup Value1 = {Binding Path = Key}}" Grid.Column="0" />
<TextBox Tag="{Binding Key, Mode=OneWay}" Text="{Binding Value, Mode=OneWay}" Width="200" Height="46" VerticalContentAlignment="Center" Grid.Column="1" LostFocus="TextBox_OnLostFocus" />
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
I can't find any workaround..I need the dictionary as item source because the label will show the key and the textbox the corresponding value..I tried also replacing the dictionary with a list of object but the problem still remains.
Does anyone have a good hint? Thanks in advance.

Answer 1

As suggested by Ed Plunkett, the solution is the ValueConverter.
So the label is know this:
<Label Content="{Binding Key, Converter={StaticResource MultiLangConverter}}" Grid.Column="0" />
where my ValueConverter is the following:
public class StringToMultiLangConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var stringValue = (string) value;
if (string.IsNullOrEmpty(stringValue))
return string.Empty;
string multiLang = LangTranslator.GetString(stringValue);
return multiLang ?? value;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return DependencyProperty.UnsetValue;
}
}
Thanks for the help!