How can I set a Static/Dynamic resource from a binding value? - wpf

Question

I want to add dynamic items with a datatemplate that contains a TextBlock control, but the text of the TextBlock control will be selected from a XAML ResourceDictionary. The staticresource name will be obtained based on the result of the binding value.
How can I do that?
I'm trying something like this, but doesn't works.
<DataTemplate x:Key="languageItemTemplate">
<ContentControl>
<StackPanel>
<TextBlock Text="{StaticResource {Binding ResourceName}}"></TextBlock>
<TextBlock Text="{DynamicResource {Binding ResourceName}}"></TextBlock>
</StackPanel>
</ContentControl>
</DataTemplate>
UPDATE
Thanks to Tobias, the fist option of his answer works. But I need to instance the converter first to get it work. Which one is the best idea to do that?
In the application_startup method and use it for all the application or in the Window.Resources of the window I use the converter?
Maybe a merge of both and do that on the Application.Resources?
thanks for your answer.
private void Application_Startup(object sender, StartupEventArgs e)
{
LoadConverters();
}
private void LoadConverters()
{
foreach (var t in System.Reflection.Assembly.GetExecutingAssembly().GetTypes())
{
if (t.GetInterfaces().Any(i => i.Name == "IValueConverter"))
{
Resources.Add(t.Name, Activator.CreateInstance(t));
}
}
}
OR
<local:BindingResourceConverter x:Key="ResourceConverter"/>
<DataTemplate x:Key="languageItemTemplate">
<ContentControl>
<StackPanel>
<TextBlock Text="{Binding Name, Converter={StaticResource ResourceConverter }}" />
</StackPanel>
</ContentControl>
</DataTemplate>

Answer 1

If the resource is an application level resource you could simply use a converter to convert from the resource name to the actual object like this:
public class BindingResourceConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
string resourceKey = value as string;
if (!String.IsNullOrEmpty(resourceKey))
{
var resource = Application.Current.FindResource(resourceKey);
if (resource != null)
{
return resource;
}
}
return Binding.DoNothing;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
And use it like this:
<TextBlock Text="{Binding ResourceKey, Converter={StaticResource ResourceConverter}}" />
If the resource is in a local scope, we need a reference to the control to search its resources. You can get the resource name and the control by using an attached property:
public class TextBlockHelper
{
public static readonly DependencyProperty TextResourceKeyProperty =
DependencyProperty.RegisterAttached("TextResourceKey", typeof(string),
typeof(TextBlockHelper), new PropertyMetadata(String.Empty, OnTextResourceKeyChanged));
public static string GetTextResourceKey(DependencyObject obj)
{
return (string)obj.GetValue(TextResourceKeyProperty);
}
public static void SetTextResourceKey(DependencyObject obj, string value)
{
obj.SetValue(TextResourceKeyProperty, value);
}
private static void OnTextResourceKeyChanged(
DependencyObject d,
DependencyPropertyChangedEventArgs e)
{
string resourceKey = e.NewValue as string;
if(d is TextBlock tb)
{
var r = tb.TryFindResource(resourceKey);
if (r != null)
{
tb.Text = r.ToString();
}
}
}
}
And you can use it like this:
<Grid>
<Grid.Resources>
<sys:String x:Key="SomeLocalResource">LocalResource</sys:String>
</Grid.Resources>
<TextBlock h:TextBlockHelper.TextResourceKey="{Binding ResourceKey}" />
</Grid>