public interface IResource{string GetString(string name);CultureInfo CurrentCulture { set; }}public interface IResourceTask{void ChangeLanguage(string language);string GetString(string name);event EventHandler LanguageChanged;}    

public interface IMessage{}public class LanguageChangedMessage : IMessage{}

    public class ResourceTask : IResourceTask{public ResourceTask(){System.Data.DataTable _dt = new System.Data.DataTable();}[ImportMany]public IResource[] Resources { get; set; }public void ChangeLanguage(string language){CultureInfo culture = new CultureInfo(language);Thread.CurrentThread.CurrentCulture = culture;Thread.CurrentThread.CurrentUICulture = culture;Resources.Apply(item => item.CurrentCulture = culture);IEventAggregator eventAggregator = IoC.Get<IEventAggregator>();eventAggregator.Publish(new LanguageChangedMessage());if (LanguageChanged != null){LanguageChanged(this, null);}}public event EventHandler LanguageChanged;public string GetString(string name){string str = null;foreach (var resource in Resources){str = resource.GetString(name);if (str != null){break;}}return str;}}

    [Export(typeof(IResource))][PartCreationPolicy(CreationPolicy.NonShared)]public class MyResource :  IResource{private ResourceManager stringResource;private CultureInfo culture = new CultureInfo("zh-cn");public CultureInfo CurrentCulture{get{return culture;}set{culture = value;}}public MyResource(){stringResource = new ResourceManager("WPFMultLanguage.Resource.MyLanguage", typeof(MyResource).Assembly);}public string GetString(string name){return stringResource.GetString(name, culture);}}

 public class MyResourceExtension : MarkupExtension, INotifyPropertyChanged, IHandle<LanguageChangedMessage>{public string Key{get;set;}public string Value{get{if (Key == null){return null;}IResourceTask result = IoC.Get<IResourceTask>();string s = result.GetString(Key);return s;}}public MyResourceExtension(){if (!Execute.InDesignMode){IoC.Get<IEventAggregator>().Subscribe(this);}}public event PropertyChangedEventHandler PropertyChanged;public void PropertyChanted(){if (PropertyChanged != null){PropertyChanged(this, new PropertyChangedEventArgs("Value"));}}public override object ProvideValue(IServiceProvider serviceProvider){IProvideValueTarget target = serviceProvider.GetService(typeof(IProvideValueTarget)) as IProvideValueTarget;Binding binding = new Binding("Value") { Source = this, Mode = BindingMode.OneWay };return binding.ProvideValue(serviceProvider) as BindingExpression;}public void Handle(LanguageChangedMessage message){PropertyChanted();}}

<Window x:Class="WPFMultLanguage.Views.MyView"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:local="clr-namespace:WPFMultLanguage.Command"xmlns:cal="http://www.caliburnproject.org"cal:Message.Attach="[Event Loaded]=[Action LoadEvent($source)]"Title="MyView" Height="300" Width="300"><StackPanel><Menu>            <MenuItem Header="{local:MyResource Key=英文}" cal:Message.Attach="[Event Click]=[Action ChanguageLanguage('en')]"></MenuItem><MenuItem Header="{local:MyResource Key=中文}"  cal:Message.Attach="[Event Click]=[Action ChanguageLanguage('zh')]"></MenuItem></Menu><TextBlock Text="{local:MyResource Key=语言}"/><Button Content="{local:MyResource Key=你好}"/><TextBox x:Name="tb_Show" Text="{local:MyResource Key=文本}"></TextBox><TextBox x:Name="tb_Load" Text="{local:MyResource Key=文本2}"></TextBox></StackPanel>
</Window>

namespace WPFMultLanguage.ViewModels
{[Export(typeof(IShell))]public class MyViewModel :Screen{public MyViewModel(){}public void LoadEvent(object obj){//var res = IoC.Get<IResourceTask>();//((MyView)GetView()).tb_Load.Text = res.GetString("文本2");
        }public void ChanguageLanguage(string lan){var res = IoC.Get<IResourceTask>();switch (lan){case "zh":res.ChangeLanguage("zh-CN");break;case "en":res.ChangeLanguage("en-US");break;}}}
}