Binding XmlDataProvider Source attribute to a static function in another form?

Question

I am trying to bind an XmlDataProvider with a Source attribute to a static function in another form.

Here's XmlDataProvider line -

<XmlDataProvider x:Key="Lang" Source="/lang/english.xml" XPath="Language/MainWindow"/>

I would like it's Source attribute to be binded to a static function called: "GetValue_UILanguage" in a form called: "Settings"

Answer 1

See this question's answer for a converter that allows you to bind to methods.

You could probably modify it to be able to access static methods of any class as well.

Edit: Here's a modified converter that should find the method via reflection.

(Note: You would be better off using a markup extension instead, as you do not actually bind any value.)

public sealed class StaticMethodToValueConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        try
        {
            var methodPath = (parameter as string).Split('.');
            if (methodPath.Length < 2) return DependencyProperty.UnsetValue;

            string methodName = methodPath.Last();

            var fullClassPath = new List<string>(methodPath);
            fullClassPath.RemoveAt(methodPath.Length - 1);
            Type targetClass = Assembly.GetExecutingAssembly().GetType(String.Join(".", fullClassPath));

            var methodInfo = targetClass.GetMethod(methodName, new Type[0]);
            if (methodInfo == null)
                return value;
            return methodInfo.Invoke(null, null);
        }
        catch (Exception)
        {
            return DependencyProperty.UnsetValue;
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException("MethodToValueConverter can only be used for one way conversion.");
    }
}

Usage:

<Window.Resources>
    ...
    <local:StaticMethodToValueConverter x:Key="MethodToValueConverter"/>
    ...
</Window.Resources>

...

<ListView ItemsSource="{Binding Converter={StaticResource MethodToValueConverter}, ConverterParameter=Test.App.GetEmps}">
...

The method in the App class:

namespace Test
{
    public partial class App : Application
    {
        public static Employee[] GetEmps() {...}
    }
}

I tested this and it works, it is important to use the full class path though, App.GetEmps alone would not have worked.