Wpf 动态创建的带多绑定和RelativeSource->Unset值的选项卡项
在我的WPF应用程序中,我希望在包含TabControl的可重用UserControl中动态创建TabItems TabControl的ItemsSource通过标准数据绑定绑定到ObservableCollection实例 调用InitializeComponent后,我创建了如下选项卡项Wpf 动态创建的带多绑定和RelativeSource->Unset值的选项卡项,wpf,xaml,dynamic,tabitem,multibinding,Wpf,Xaml,Dynamic,Tabitem,Multibinding,在我的WPF应用程序中,我希望在包含TabControl的可重用UserControl中动态创建TabItems TabControl的ItemsSource通过标准数据绑定绑定到ObservableCollection实例 调用InitializeComponent后,我创建了如下选项卡项 // ... int itemCount = 0; TabItem it = null; it = new TabItem(); it.Header = "Sicherungen + Relais"; t
// ...
int itemCount = 0;
TabItem it = null;
it = new TabItem();
it.Header = "Sicherungen + Relais";
tabItemList.Insert(itemCount++, it);
it = new TabItem();
it.Header = "Lage der Bauteile";
tabItemList.Insert(itemCount++, it);
it = new TabItem();
it.Header = "Schaltpläne";
tabItemList.Insert(itemCount++, it);
it = new TabItem();
it.Header = "Tipps + Tricks";
tabItemList.Insert(itemCount++, it);
好消息是,这些项确实被添加到TabControl中,并带有各自的标题
现在,当WPF在窗口变为可见后试图对其应用样式时,问题就出现了
对于选项卡项,我有以下默认样式:
<Style TargetType="{x:Type TabItem}"
BasedOn="{StaticResource TISTabItem}">
<Setter Property="Width">
<Setter.Value>
<MultiBinding Converter="{StaticResource convCategoryTabWidthConverter}">
<Binding RelativeSource="{RelativeSource AncestorType={x:Type TabControl}, Mode=FindAncestor}" />
<Binding RelativeSource="{RelativeSource AncestorType={x:Type TabControl}, Mode=FindAncestor}"
Path="ActualWidth" />
</MultiBinding>
</Setter.Value>
</Setter>
</Style>
和转换器:
public class CategoryTabWidthConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
if (values == null || values.Count() < 1)
throw new ArgumentException("Values array passed is invalid.", "values");
if(values[0] == DependencyProperty.UnsetValue)
{
return 0; // Added for breakpoint. Bailing out here!!!
}
TabControl tabCtrl = values[0] as TabControl;
Double w = (tabCtrl.ActualWidth / tabCtrl.Items.Count);
w = (w <= 1) ? 0.0 : (w - 1);
return w;
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
备注:我在另外两个地方使用这个转换器和样式,其中TabItems是在XAML中静态添加的!在这些情况下,一切都很好
但是,当动态添加TabItems时,TabControl RelativeSource及其实际宽度都会计算为DependencyProperty.UnsetValue
我希望在这里遇到一些逻辑错误
什么时候应用样式?在将选项卡项正确添加到内部树之前还是之后?
有人知道我做错了什么吗
我会进一步调查,并提前感谢你们的帮助。我自己解决了这个问题。问题是我忘记了ItemsSource的元素将被包装到TabItem实例中 TabItem中的TabItem实际上没有意义 直接将它们插入TabControl。Items使其工作起来令人惊讶