Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>You can use something like this to keep your ObservableCollections synchronised between the model and view model:</p> <pre><code>/// &lt;summary&gt; /// Keeps one collection synchronised with another. /// &lt;/summary&gt; /// &lt;typeparam name="Source"&gt;The type of the source items.&lt;/typeparam&gt; /// &lt;typeparam name="Destination"&gt;The type of the destination items.&lt;/typeparam&gt; public class CollectionSync&lt;Source, Destination&gt; { private readonly Func&lt;Source, Destination&gt; _destItemFactory; private readonly Action&lt;Destination&gt; _destItemRemover; private readonly IList&lt;Destination&gt; _destList; private readonly IList&lt;Source&gt; _sourceList; /// &lt;summary&gt; /// Initializes a new instance of the &lt;see cref="CollectionSync&amp;lt;Source, Destination&amp;gt;"/&gt; class. /// &lt;/summary&gt; /// &lt;param name="sourceList"&gt;The source list.&lt;/param&gt; /// &lt;param name="destList"&gt;The destination list.&lt;/param&gt; /// &lt;param name="destItemFactory"&gt;Factory method which creates a Destination for a given Source.&lt;/param&gt; /// &lt;param name="destItemRemover"&gt;Method called when a Destination is removed.&lt;/param&gt; public CollectionSync(IList&lt;Source&gt; sourceList, IList&lt;Destination&gt; destList, Func&lt;Source, Destination&gt; destItemFactory, Action&lt;Destination&gt; destItemRemover) { _destItemFactory = destItemFactory; _destItemRemover = destItemRemover; _sourceList = sourceList; _destList = destList; ((INotifyCollectionChanged) _sourceList).CollectionChanged += SourceCollection_CollectionChanged; PopulateWithAllItems(); } private void PopulateWithAllItems() { foreach (Source sourceItem in _sourceList) _destList.Add(_destItemFactory(sourceItem)); } private void SourceCollection_CollectionChanged(object sender, NotifyCollectionChangedEventArgs args) { switch (args.Action) { case NotifyCollectionChangedAction.Add: OnItemsAdded(args.NewStartingIndex, args.NewItems); break; case NotifyCollectionChangedAction.Remove: OnItemsRemoved(args.OldStartingIndex, args.OldItems); break; case NotifyCollectionChangedAction.Reset: OnItemsReset(); break; case NotifyCollectionChangedAction.Move: case NotifyCollectionChangedAction.Replace: throw new NotImplementedException(); } } private void OnItemsReset() { _destList.Clear(); PopulateWithAllItems(); } private void OnItemsRemoved(int index, ICollection items) { int itemCount = items.Count; for (int i = 0; i &lt; itemCount; i++) { Destination removed = _destList[index]; _destList.RemoveAt(index); if (_destItemRemover != null) _destItemRemover(removed); } } private void OnItemsAdded(int index, IList items) { int itemIndex = index; foreach (Source item in items) { // Add to Items collection _destList.Insert(itemIndex, _destItemFactory(item)); itemIndex++; } } } </code></pre> <p>Taking your Order/OrderDetails example, in your Order view model you would hook up the two ObservableCollections like this:</p> <pre><code>_modelToViewModelSync = new CollectionSync&lt;IOrderDetail, OrderDetailViewModel&gt;( orderDetailModels, // the list of your order details models OrderDetails, // the list of order details view models exposed by the Order view model x =&gt; new OrderDetailViewModel(x), // factory method to create a view model null); // do something here if you care when your view models are removed </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POSilverlight MVVM header detail
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USGraemeF
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload