如何在更改语言属性后更改ComboBox CHOOSE AN ITEM标头

Question

我们正在本地化我们的应用，并允许用户在应用运行时动态更改语言。

除了允许他们更改语言的ComboBox之外，这项工作正常。

这是XAML

    <ComboBox
    x:Name="label_Languages"
    x:Uid="label_Languages"
    Header="Preferred language"
    ItemsSource="{Binding Languages}"
    SelectedItem="{Binding LanguageSelected, Mode=TwoWay}"
    PickerFlyoutBase.Title="{Binding Title, Mode=OneWay}"
    SelectedValuePath="Name"
    SelectionChanged="label_Languages_SelectionChanged" >
  <ComboBox.ItemTemplate>
    <DataTemplate>
      <StackPanel Orientation="Vertical">
        <TextBlock Text="{Binding NativeName}" />
        <TextBlock Text="{Binding EnglishName}" FontSize="14" Foreground="{ThemeResource TextBoxForegroundHeaderThemeBrush}" />
      </StackPanel>
    </DataTemplate>
  </ComboBox.ItemTemplate>
</ComboBox>

这是C＃

    private void label_Languages_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    ComboBox languages = sender as ComboBox;

    SettingsViewModel vm = DataContext as SettingsViewModel;

    SettingsViewModel.Language language = label_Languages.SelectedItem as SettingsViewModel.Language;
    if (language != null)
    {
        string locale = language.Name;
        App.ChangeAppLanguage(locale);
        page_SettingsPage.Language = App.CultureInfo.Name;
        page_SettingsPage.FlowDirection = App.FlowDirection;

        // Modify the language of each page UI element and render it in the new language.

        label_Languages.Header = ResourceStrings.GetString("label_Languages.Header");

        // update a bunch of other items that all work perfectly!
    }
}

以下是前后截图，展示了选择和项目如何变化。

如何让ComboBox更改标题？感谢您对此感兴趣。

[UPDATE]

基于@Dev Dua的建议，我添加了PickerFlyoutBase.Title =＆＃34; {Binding Title，Mode = OneWay}＆＃34;到ComboBox XAML并将Title属性添加到ViewModel。在ViewModel中更改语言后，Title属性的RaisePropertyChanged将导致稍后检索Title属性。大概是由PickerFlyoutBase.Title绑定。不幸的是，即使Title属性返回了正确的值，ComboBox也会继续显示英文选择项目。

这是ViewModel：

    public Language _LanguageSelected = null;
    public Language LanguageSelected
    {
        get { return _LanguageSelected; }
        set
        {
            _LanguageSelected = value;
            App.ChangeAppLanguage(_LanguageSelected.Name);
            RaisePropertyChanged("LanguageSelected");
            RaisePropertyChanged("Title");
        }
    }

    public string Title
    { get { return ResourceStrings.GetString("LanguageChooseAnItem.Title"); } }

ComboBox绑定到PickerFlyoutBase.Title属性时出现问题。在XAML中使用字符串常量可以按预期工作。

Answer 1

使用PickerFlyoutBase.Title属性！将它绑定到要显示的任何文本。

 <ComboBox PlaceholderText="Something here" PickerFlyoutBase.Title="Edited">
            <ComboBoxItem Content="A"/>
            <ComboBoxItem Content="B"/>
            <ComboBoxItem Content="C"/>
            <ComboBoxItem Content="D"/>
            <ComboBoxItem Content="A"/>
            <ComboBoxItem Content="A"/>
 </ComboBox>