集合视图是关于排序、过滤、分组的。它们与数据转换无关。
实际上,您的任务解释中没有直接需要这样的集合。您只需要正确设置视图DataTemplate
,例如为源集合中的项目提供正确的:
public class MyEntity
{
public int Id { get; set; }
public string Name { get; set; }
}
public class MyViewModel
{
public ObservableCollection<MyEntity> Entities { get; private set; }
public ICollectionView EntitiesView
{
if (view == null)
{
view = new ListCollectionView(Entities);
}
return view;
}
private ICollectionView view;
}
XAML:
<DataTemplate DataType="{x:Type local:MyEntity}">
<!-- This "transforms" visual representation of your entity, but the entity itself (and its container) remains unchanged -->
<TextBlock Text="{Binding Name}"/>
</DataTemplate>
更新。根据您的评论,我会将实体包装到视图模型中。此外,这是视图模型的目的:
public class MyEntityViewModel
{
private readonly MyEntity model;
public MyEntityViewModel(MyEntity model)
{
this.model = model;
}
public int MyInt
{
get { return model. // some logic to retrieve int ... }
}
public string MyString
{
get { return model. // some logic to retrieve string ... }
}
}
然后,我将控件绑定到视图模型集合,而不是模型集合:
public class MyViewModel
{
public MyViewModel(ICollection<MyEntity> entities)
{
this.Entities = new ObservableCollection<MyEntityViewModel>(entities.Select(e => new MyEntityViewModel(e)));
// this will keep two collections synchronized:
this.Entities.CollectionChanged += (sender, args) =>
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
entities.Add((MyEntity)e.NewItems[0]);
break;
case NotifyCollectionChangedAction.Remove:
entities.Remove((MyEntity)e.OldItems[0]);
break;
case NotifyCollectionChangedAction.Replace:
entities.Remove((MyEntity)e.OldItems[0]);
entities.Add((MyEntity)e.NewItems[0]);
break;
case NotifyCollectionChangedAction.Reset:
entities.Clear();
break;
}
}
}
public ObservableCollection<MyEntityViewModel> Entities { get; private set; }
}
这将使您的数据类远离额外的属性,这些属性仅供查看。