我有一个奇怪的情况。我为WinRT开发一个应用程序，并在命令绑定方面存在一些问题。这是XAML的一部分：
<control:ItemsHub ItemsSource="{Binding Categories}">
<control:ItemsHub.SectionHeaderTemplate>
<DataTemplate>
<Button Command="{Binding CategoryNavigationCommand}" Margin="5,0,0,10" Content="{Binding Header}"/>
</DataTemplate>
</control:ItemsHub.SectionHeaderTemplate>
</control:ItemsHub>
这是我的ViewModel：
public CategorySectionViewModel(IRecipeService recipeService, INavigationService navigationService, RecipeTreeItemDto treeItem)
{
...
CategoryNavigationCommand = new DelegateCommand(NavigateToCategory);
...
}
private string _header;
public string Header
{
get { return _header; }
set { SetProperty(ref _header, value); }
}
public DelegateCommand CategoryNavigationCommand { get; private set; }
private void NavigateToCategory()
{
_navigationService.Navigate("CategoryHub", _recipeTreeItemDto.NodePath);
}
我在输出窗口中没有任何绑定错误，并且"标头"也显示在按钮中。但是命令不会被解雇，我点击它！我做错了什么？
也许是因为我创建了一个自定义HubControl。使用此控件，我可以为枢纽标题和轮毂符合体附加一个项目库和ItemTemplate。也许是因为这种绑定丢失了？
这是我的自定义集线器控件：
public class ItemsHub : Hub
{
public DataTemplate ItemTemplate
{
get { return (DataTemplate)GetValue(ItemTemplateProperty); }
set { SetValue(ItemTemplateProperty, value); }
}
public IList ItemsSource
{
get { return (IList)GetValue(ItemsSourceProperty); }
set { SetValue(ItemsSourceProperty, value); }
}
public HubSection SpotlightSection
{
get { return (HubSection)GetValue(SpotlightSectionProperty); }
set { SetValue(SpotlightSectionProperty, value); }
}
public DataTemplate SectionHeaderTemplate
{
get { return (DataTemplate)GetValue(SectionHeaderTemplateProperty); }
set { SetValue(SectionHeaderTemplateProperty, value); }
}
public static readonly DependencyProperty ItemTemplateProperty =
DependencyProperty.Register("ItemTemplate", typeof(DataTemplate), typeof(ItemsHub), new PropertyMetadata(null, ItemTemplateChanged));
public static readonly DependencyProperty ItemsSourceProperty =
DependencyProperty.Register("ItemsSource", typeof(IList), typeof(ItemsHub), new PropertyMetadata(null, ItemsSourceChanged));
public static readonly DependencyProperty SpotlightSectionProperty =
DependencyProperty.Register("SpotlightSection", typeof(HubSection), typeof(ItemsHub), new PropertyMetadata(default(HubSection), SpotlightSectionChanged));
public static readonly DependencyProperty SectionHeaderTemplateProperty =
DependencyProperty.Register("SectionHeaderTemplate", typeof(DataTemplate), typeof(ItemsHub), new PropertyMetadata(default(DataTemplate), HeaderTemplateChanged));
private static void SpotlightSectionChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
bool hubContainsSpotLight = hub.Sections.Contains(hub.SpotlightSection);
if (hub.SpotlightSection != null && !hubContainsSpotLight)
{
hub.Sections.Add(hub.SpotlightSection);
}
if (hub.SpotlightSection == null && hubContainsSpotLight)
{
hub.Sections.Remove(hub.SpotlightSection);
}
}
}
private static void HeaderTemplateChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
DataTemplate template = e.NewValue as DataTemplate;
if (template != null)
{
// Apply template
foreach (var section in hub.Sections.Except(new List<HubSection> { hub.SpotlightSection }))
{
section.HeaderTemplate = template;
}
}
}
}
private static void ItemTemplateChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
DataTemplate template = e.NewValue as DataTemplate;
if (template != null)
{
// Apply template
foreach (var section in hub.Sections.Except(new List<HubSection> { hub.SpotlightSection }))
{
section.ContentTemplate = template;
}
}
}
}
private static void ItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
IList items = e.NewValue as IList;
if (items != null)
{
var spotLightSection = hub.SpotlightSection;
hub.Sections.Clear();
if (spotLightSection != null)
{
hub.Sections.Add(spotLightSection);
}
foreach (var item in items)
{
HubSection section = new HubSection();
section.DataContext = item;
section.Header = item;
DataTemplate headerTemplate = hub.SectionHeaderTemplate;
section.HeaderTemplate = headerTemplate;
DataTemplate contentTemplate = hub.ItemTemplate;
section.ContentTemplate = contentTemplate;
hub.Sections.Add(section);
}
}
}
}
}
感谢您的帮助！
我找到了解决方案！我不知道为什么，但是默认情况下，集线器控件的截面标题不是交互式！因此，当我在自定义itemHub-control中分配项目库时，我必须将交互性设置为true。
这是我在ItemShub控件中更改的内容：
private static void ItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
IList items = e.NewValue as IList;
if (items != null)
{
var spotLightSection = hub.SpotlightSection;
hub.Sections.Clear();
if (spotLightSection != null)
{
hub.Sections.Add(spotLightSection);
}
foreach (var item in items)
{
HubSection section = new HubSection();
DataTemplate headerTemplate = hub.SectionHeaderTemplate;
section.HeaderTemplate = headerTemplate;
DataTemplate contentTemplate = hub.ItemTemplate;
section.ContentTemplate = contentTemplate;
section.DataContext = item;
section.Header = item;
//This line fixed my problem.
section.IsHeaderInteractive = true;
hub.Sections.Add(section);
}
}
}
您可以使用以下绑定表达式
command =" {binding categoryNavigationCommand，reactricesource = {reactractiOrce ancestortype = xyx}}}"
和xyz是一种控制类型