c# - 如何保存在wpf中绑定(bind)到ObservableCollection的tabcontrol项的Tab键顺序？

我有一个ObservableCollection绑定(bind)到tabcontrol。

<TabControl
    ItemsSource="{Binding Steps}"
    SelectedItem="{Binding SelectedStep}"
    CanUserReorder="{Binding EditMode}"
</TabControl>

如果用户处于EditMode，则可以重新排序选项卡项。
当我离开带有tab控件的 View 时，我失去了由用户修改的Tab键顺序。
我该如何预防？

谢谢你的帮助!

最佳答案

我得到了它!
该解决方案在mvvm-pattern中实现。

每次更改收集步骤时，请添加或删除项目，然后重新排列其位置。
用户可以通过使用ComponentOne的TabControl或使用Bea Stollnitz的拖放功能来重新排序View中TabControl的TabItem。

ViewModel:

public class MyViewModel
{
    public MyModel Model {/*get... set*/}
    public ObservableCollection<StepViewModel> Steps {/*get... set...*/}
    public StepViewModel SelectedStep {/*get... set...*/}

    public MyViewModel()
    {
        Model = new MyModel();
        Steps = new ObservableCollection<StepViewModel>();
        Model.Steps = new ObservableCollection<StepModel>();
        // Load the saved Model with the steps and their positions
        Model.Steps = LoadFromXml();

        Steps.CollectionChanged += Steps_OnCollectionChanged;
        // Add the Steps in the right order
        for (int i = 0; i < Steps.Count; i++)
        {
             var item = Steps.First(x => x.Position == i);
             var vm = new StepViewModel();
             Steps.Add(vm);
        }
    }

    private void Steps_OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (e.Action == NotifyCollectionChangedAction.Add)
        {
            foreach (StepViewModel vm in e.NewItems)
            {
                if (!Model.Steps.Contains(vm.Model))
                    Model.Steps.Add(vm.Model);
            }
        }
        else if (e.Action == NotifyCollectionChangedAction.Remove)
        {
            foreach (StepViewModel vm in e.OldItems)
            {
                if (Model.Steps.Contains(vm.Model))
                    Model.Steps.Remove(vm.Model);
            }
        }
        // Match the temporary collectionindex to a position-property
        foreach (StepViewModel item in Steps)
        {
            item.Position = Steps.IndexOf(item);
        }
    }

}