Question

我试图根据SelectedDay的Date属性的值导航到ListCollectionView中的特定项目。

VM

private Day _selectedDay;
public Day SelectedDay    // the Name property
{
     get { return _selectedDay; }
     set { _selectedDay = value; RaisePropertyChanged(); }
}

public ObservableCollection<ShootingDay> AllShootingDayInfo {get; set;}

private ListCollectionView _shootingDayInfoList;
public ListCollectionView ShootingDayInfoList
{
    get
    {
        if (_shootingDayInfoList == null)
        {
            _shootingDayInfoList = new ListCollectionView(AllShootingDayInfo);}
            return _shootingDayInfoList;
    }
    set
    {
        _shootingDayInfoList = value; RaisePropertyChanged();
    }
}

<Day>对象的属性为Date，我希望它与Date对象中的<ShootingDay>属性匹配，以便我可以导航到ShootingDayInfoList其中SelectedDay.Date与Date内的ShootingDayInfoList项匹配。

我已尝试过此功能，但由于所选项目不属于同一个对象，因此无法正常工作。

ShootingDayInfoList.MoveCurrentTo(SelectedDay.Date);

我该如何使这项工作？我对这一切都很陌生。

Answer 1

您需要Filter谓词来获取所需的项目，然后移除Filter以恢复所有项目。

代码

ViewModel vm = new ViewModel();
System.Diagnostics.Debug.WriteLine(vm.ShootingDayInfoList.Count.ToString());
vm.SelectedDay.Date = DateTime.Parse("12/25/2015");

vm.ShootingDayInfoList.Filter = (o) =>
{
    if (((ShootingDay)o).Date.Equals(vm.SelectedDay.Date))
        return true;

    return false;
};

ShootingDay foundItem = (ShootingDay)vm.ShootingDayInfoList.GetItemAt(0);
vm.ShootingDayInfoList.Filter = (o) => { return true; };

vm.ShootingDayInfoList.MoveCurrentTo(foundItem);

我已使用MoveCurrentToNext() method检查了代码，但它运行正常。这种方法不会影响您现有的代码。

第二种方法，直接使用AllShootingDayInfo或使用SourceCollection属性获取基础Collection：

    ViewModel vm = new ViewModel();
    System.Diagnostics.Debug.WriteLine(vm.ShootingDayInfoList.Count.ToString());
    vm.SelectedDay.Date = DateTime.Parse("12/23/2015");

    IEnumerable<ShootingDay> underlyingCollection = ((IEnumerable<ShootingDay>)vm.ShootingDayInfoList.SourceCollection);

    ShootingDay d1 = underlyingCollection.FirstOrDefault(dt => dt.Date.Equals(vm.SelectedDay.Date)); 

    vm.ShootingDayInfoList.MoveCurrentTo(d1);

导航到ListCollectionView中的特定项

1 个答案: