WPF 綁定未在 DataGrid 中更新（帶分組）

Question

我知道有很多關於綁定問題的問題。 但我還沒有找到任何解決方案——我也不知道我的代碼有什么問題。

我有 2 Collections：

public ObservableCollection<TicketEntry> AllEntries  {get; set;}

public ObservableCollection<TicketEntry> Entries {get; set;}

Entity有一個屬性IsFavourite ：

private bool _isFavourite = false;
public bool IsFavourite
{
    get { return _isFavourite; }
    set
    {
        _isFavourite = value;
        OnPropertyChanged();
        OnPropertyChanged("ImageSource");
}

string ImageSource
{
    get
    {
        if (IsFavourite)
        {
            return "pack://application:,,,/Resources/star_true.png";
        }
        else
        {
            return "pack://application:,,,/Resources/star_false.png";
        }
    }
}

---

<CollectionViewSource x:Key="Collection" 
                      Source="{Binding Entries, 
                               UpdateSourceTrigger=PropertyChanged, 
                               Mode=TwoWay, 
                               NotifyOnSourceUpdated=True}"
                      xmlns:s="clr-namespace:System;assembly=mscorlib">
        <CollectionViewSource.GroupDescriptions>
            <PropertyGroupDescription PropertyName="IsFavourite" />
        </CollectionViewSource.GroupDescriptions>
        <CollectionViewSource.LiveGroupingProperties>
            <s:String>IsFavourite</s:String>
        </CollectionViewSource.LiveGroupingProperties>
    </CollectionViewSource>

---

//Handler for Command ((un)set-favourite)
private void HandleInvertFavourite()
    {
        if (IsFavourite)
        {
            IsFavourite = false;
        }
        else
        {
            IsFavourite = true;
        }
        AllTicketsViewModel.Instance.InvokeFavouritesChanged(this);
    }



internal void InvokeFavouritesChanged(TicketEntry ticketEntry)
{
    if(ticketEntry.IsFavourite) // Add
        {
            if(CurrentWeekViewModel.Instance.Entries.Any(x => x.TicketId == ticketEntry.TicketId)) // already exists
            {
                TicketEntry existingentry = CurrentWeekViewModel.Instance.Entries.First(x => x.TicketId == ticketEntry.TicketId);
                CurrentWeekViewModel.Instance.Entries.First(x => x.TicketId == ticketEntry.TicketId).IsFavourite = true;
            }
            else
            {
                CurrentWeekViewModel.Instance.Entries.Add(ticketEntry);
            }
        }
        else // Remove
        {
            if(CurrentWeekViewModel.Instance.Entries.Any(x => x.TicketId == timeTicketEntry.TicketId))
            {
                TicketEntry existingentry = CurrentWeekViewModel.Instance.Entries.First(x => x.TicketId == ticketEntry.TicketId);
                if (existingentry.TimeBookings.Any(x => x.Date > CurrentWeekViewModel.Instance.SelectedWeek.FirstDay &&
                                                        x.Date < CurrentWeekViewModel.Instance.SelectedWeek.LastDay &&
                                                        existingentry.IsFavourite))
                //has time data for actual week => keep but set fav = false
                {

                    existingentry.IsFavourite = false;
                }
                else // completely remove
                {

                    CurrentWeekViewModel.Instance.Entries.Remove(existingentry);
                }
            }
        }
}

此外， CurrentWeek -DataGird 在IsFavourite上有Grouping - 我希望現有條目在IsFavourite_Changed上切換組。

我檢查過的事情：

• 綁定是正確的
• INotifyPropertyChanged 正確實現
• 添加新的收藏夾有效（只有現有的有問題）

為什么當屬性改變時分組沒有改變？

Answer 1

將CollectionViewSource的IsLiveGroupingRequested屬性設置為true 。

Answer 2

嘗試刷新組

ICollectionView groupedList = CollectionViewSource.GetDefaultView(items);
groupedList.Refresh();