caliburn.micro - 在 Caliburn 中初始化 Binded int 属性值不会将其映射到 mahApps SplitButton SelectedIndex 属性

Question

我正在初始化这样的值：（MahApps.Metro 1.1.3-ALPHA）

private int currentCulture;
public int CurrentCulture
{
    get { return currentCulture; }
    set
    {
        if (currentCulture != value)
        {
            currentCulture = value;
            LocalizeDictionary.Instance.Culture = Languages[value];
            NotifyOfPropertyChange(() => CurrentCulture);
        }
    }
}       

protected override void OnInitialize()
{
    base.OnInitialize();
    Languages.AddRange(BS.Expert.Client.App.Utils.Resources.GetAvailableCultures());
    CurrentCulture = Languages.IndexOf(new CultureInfo(LocalizeDictionary.Instance.Culture.Name));
    ...

问题是当视图启动时我没有看到 dropDown mahApps 控件中设置的值......，这是怎么回事？

<Controls:SplitButton
     Orientation="Horizontal"
     x:Name="Languages"
     cal:Message.Attach="[Event SelectionChanged] = [Action ChangeCulture($eventArgs)]"
     DisplayMemberPath="DisplayName"
     SelectedIndex="{Binding CurrentCulture, ElementName=SplitButton0, Mode=TwoWay}" >
 </Controls:SplitButton>