Collectionviewsource and observablecollections WP 8.1

Question

Hello,

I'm not sure how to go about using a collectionviewsource with WP 8.1 and listview.

I'm using the MVVM-pattern with all code inside CatViewModel.xaml.cs, and all xaml inside app.xaml.

I have a model which is a set of cats that's inside a database where I fetch data with sqlite.

Now obviously I want to return this observablecollection to my app.xaml, but I'm getting nothing in there. If i put a breakpoint on my ICollectionView get-statement it never gets there. Items is never called.

app.xaml

Datatemplate of my listview

<Grid.Resources>
 <CollectionViewSource x:Name="Items" IsSourceGrouped="True"/>
</Grid.Resources>

<ListView ItemsSource="{Binding Source={StaticResource Items}}"
                              IsItemClickEnabled="False" ItemTemplate="{StaticResource CatIT}">

itemtemplate CatIT

<ListViewItem>
    <TextBlock Text="{Binding Cat}" Grid.Row="0" Grid.Column="0" Style="{StaticResource SmallFont}" />
</ListViewItem>
    

CatViewModel.xaml.cs (This code below is a rip from Alexanders code)
http://social.msdn.microsoft.com/Forums/silverlight/en-US/29699048-3ecb-407e-a28c-cd826024fbb2/using-collectionviewsource-in-mvvm?forum=silverlightcontrols

private CollectionViewSource items;
public ICollectionView Items
{
	get
	{
		if (items == null)
		{
			items = new CollectionViewSource();
                        //where listOfDataObjects is collection of your data objects
                        //that you want to display
			items.Source = new ObservableCollection<DataObject>(listOfDataObjects);

		}

		return items.View;
	}
}

Answer 1

Not sure what the issue could be from what you have posted.

Please post a sample project showing the problem on OneDrive

---

Jeff Sanders (MSFT)

@jsandersrocks - Windows Store Developer Solutions @WSDevSol
Getting Started With Windows Azure Mobile Services development? Click here
Getting Started With Windows Phone or Store app development? Click here
My Team Blog: Windows Store & Phone Developer Solutions
My Blog: Http Client Protocol Issues (and other fun stuff I support)

Answer 2

Sorry Jeff about the delay. I have been away for one day.

I created a new project and came up with a simpler version but now what's displayed is only the print screen. "Utmaningen" is my Project, .model is my folder where I have my models.

This is a new version of my code. I am trying to keep it to the absolute simplest possible but out of all code models, going from knowing nothing of coding to learning MVVM, async-tasks, WCF in azure, Sqlite, and local databases to make my app all in C# in about one year I think this is the hardest to wrap my head around. :) I read many articles online and all but they are all so conflicting. And many includes the longlistselector.

App.xaml

  <ListView ItemsSource="{Binding Path=CatSorted}" >
                                              <ListView.GroupStyle>
                        <GroupStyle>
                            <GroupStyle.HeaderTemplate>
                                <DataTemplate>
                                    <TextBlock Text="{Binding Key}" Foreground="White" />
                                </DataTemplate>
                            </GroupStyle.HeaderTemplate>
                        </GroupStyle>
                    </ListView.GroupStyle>
</Listview>

Folder viewmodel

catviewmodel.xaml.cs

 private CollectionViewSource catSorted;
 public ICollectionView CatSorted
        {
            get
            {
                if (catSorted == null)
                {
                    catSorted = new CollectionViewSource();

                        var GroupedCatsByDate = from c in cats.GetCats() 
                                                group c by e.CatDate into groupedByDate
                                                select new KeyedList<string, CatModel>(groupedByDate);

                        catSorted.Source = new ObservableCollection<KeyedList<string, CatModel>>(grouedByDate);
                                   }
                return catSorted.View;
            }
        }

Answer 3

Does anyone have an idea about this problem?

Answer 4

I'll try once more othervise I'll close the thread. Anyone?

Answer 5

Please post a simple repro project to onedrive showing the issue and you attempt to resolve it. 

---

Jeff Sanders (MSFT)

@jsandersrocks - Windows Store Developer Solutions @WSDevSol
Getting Started With Windows Azure Mobile Services development? Click here
Getting Started With Windows Phone or Store app development? Click here
My Team Blog: Windows Store & Phone Developer Solutions
My Blog: Http Client Protocol Issues (and other fun stuff I support)

Answer 6

Did anyone else have an idea about this? Without having to upload my entire app?