我想要将我的TabControl
的内容绑定到我的StepViewModel
的实例的ObservableCollection
步骤。如何将tabcontrol内容的datacontext绑定到observablecollection中的视图模型的实例
我ProcessViewModel:
pubic class ProcessViewModel : ViewModelBase
{
public ObservableCollection<StepViewModel> Steps
{
get { return _steps; }
set { _steps = value; OnPropertyChanged("Steps"); }
}
public StepViewModel SelectedStep
{
// like above...
}
}
我StepViewModel(DataContext的应该是ProcessVM的步骤StepVMs):
public class StepViewModel : ViewModelBase
{
public string Name { get {...} set {...} }
public object Media { get {...} set {...} }
//...
}
我的TabControl(DataContext的是ProcessViewModel):
<C1:C1TabControl
ItemsSource="{Binding Steps}"
SelectedItem="{Binding SelectedStep}"
SelectionChanged="{tcSteps_OnSelectionChanged">
<C1:C1TabControl.ContentTemplate>
<DataTemplate>
<local:StepView
DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type vmns:ProcessViewModel}}, Path=SelectedStep}"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch">
</local:StepView>
</DataTemplate>
</C1:C1TabControl.ContentTemplate>
</C1:C1TabControl>
编译器提供以下输出消息:
"System.Windows.Data Error: 40 : BindingExpression path error: 'SelectedStep' property not found on 'object' ''StepViewModel' (HashCode=32952144)'. BindingExpression:Path=SelectedStep; DataItem='StepViewModel' (HashCode=32952144); target element is 'StepView' (Name='StepView'); target property is 'DataContext' (type 'Object')"
有谁知道我该如何解决? 谢谢!
您是否有在StepViewModel中定义的名为SelectedStep的属性? – Versatile
看起来像在C1TabControl中存在一个问题,因此它不像您期望的那样绑定数据上下文。这在错误中显示,该绑定尝试在“StepViewModel”而不是“ProcessViewModel”上查找“SelectedStep”属性。简而言之,看看在控件中如何使用C1TabControl.SelectedItem属性。 – ibebbs
'vmns:ProcessViewModel'不是可视化树的一部分,所以你不能使用AncestorType来找到它。你可以用AncestorType做的事情是找到一个* control *,它的'DataContext'是'vmns:ProcessViewModel',它似乎是你的选项卡控件:'DataContext =“{Binding DataContext.SelectedStep,RelativeSource = {RelativeSource AncestorType = {x:类型C1:C1TabControl}}}“' –