导航SelectedItem时更新ListCollectionView

Question

我有一个ListCOllectionView，它绑定到一个列表框。当我点击它，我可以选择一个项目。现在，我希望能够转到列表框中的前一项和下一项，并同时选择它。

我的列表箱

<ListBox x:Name="Imported_images" SelectedItem="{Binding SelectedImage}" ItemsSource="{Binding SortedImageLibrary}"/>

<Button x:Name="next" Command="{Binding NextImageCommand}" >
<Button x:Name="previous" Command="{Binding PreviousImageCommand}">

ViewModel

private ListCollectionView _sortedImageLibrary;
public ListCollectionView SortedImageLibrary
{
    get
    {
        if (_sortedImageLibrary == null) 
        {
            _sortedImageLibrary = new ListCollectionView(ImageLibrary);
            _sortedImageLibrary.IsLiveSorting = true;
            _sortedImageLibrary.CustomSort = new ImageComparer();                     
         }
        return _sortedImageLibrary; 
    }
    set
    {
        _sortedImageLibrary = value; RaisePropertyChanged();
    }
}

private Image _selectedImage;
public Image SelectedImage   
{
    get { return _selectedImage; }
    set { _selectedImage = value; RaisePropertyChanged("SelectedImage"); }
}

public RelayCommand NextImageCommand { get; set; }
public RelayCommand PreviousImageCommand { get; set; }
public void PreviousImageExecute()
{
    if (SortedImageLibrary.CurrentPosition == 0)
    {
    }
    else
    {
        SortedImageLibrary.MoveCurrentToPrevious();
    }
}
public void NextImageExecute()
{
    if (SortedImageLibrary.CurrentPosition == SortedImageLibrary.Count - 1)
    {
    }
    else
    {
        SortedImageLibrary.MoveCurrentToNext();
    }
}

我可以转到ListCollectionView中的下一项和前一项，但是SelectedImage不更新。当我在ListCollectionView中导航时，如何更新选定的图像？

Answer 1

我认为您只需要在导航上设置SelectedImage属性的实例。PropertyChangedEvent应该在WPF端触发更新。

我不确定，但我想应该像这样：

public void PreviousImageExecute()
{
    if (SortedImageLibrary.CurrentPosition == 0)
    {
    }
    else
    {
        SortedImageLibrary.MoveCurrentToPrevious();
    }
    SelectedImage = SortedImageLibrary.CurrentItem as Image;
}
public void NextImageExecute()
{
    if (SortedImageLibrary.CurrentPosition == SortedImageLibrary.Count - 1)
    {
    }
    else
    {
        SortedImageLibrary.MoveCurrentToNext();
    }
    SelectedImage = SortedImageLibrary.CurrentItem as Image;
}

Answer 2

导航之后，应该将CurrentItem分配给SelectedImage属性。当然，您需要评估您的导航方法是否在分配之前返回true。