CODEWITHSUNDEEP
c#wpfentity-frameworklistview
Brodie
Brodie

Reputation: 43

ListView Data Won't Refresh in WPF App

I am trying to load data into a ListView in WPF using a Stored Procedure and Entity Framework. When I first load the User Control the ListView loads the data just fine. I then call the same code to refresh the data and I can see through debugging that the ListItems count changes but the data on the front end screen does not update.

XAML

<ListView Name="DocsListView" ItemsSource="{Binding}">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Documents" DisplayMemberBinding="{Binding Documents}"/>
        </GridView>
    </ListView.View>
</ListView>

Code Behind

public void LoadDocs()
{
    Context _Context = new Context();
    DocsListView.ItemsSource = null;
    DocsListView.ItemsSource = _Context.SP_GetDocuments(1).ToList();
    _Context = null;
}

Can someone please help me figure out what I'm doing wrong? I'm using VS2012, .Net 4.5, and EF 5.0.

Upvotes: 4

Views: 6379

Answers (1)

makim
makim

Reputation: 3284

I´m not sure whats causing the Problem, generally I would recommend to use a DependencyProperty!

But you could try to refresh the ListView like that:

ICollectionView view = CollectionViewSource.GetDefaultView(DocsListView.ItemsSource);
view.Refresh();

If this is going to be a bigger Project I strongly recommend to have a look at the MVVM DesignPattern!

WPF and MVVM play well together. There are nice Libraries you can use like MVVMLight.

Also you should have a look at the INotifyPropertyChanged Interface.

XAML-Code (Don´t forget to set the DataContext)

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525"
        DataContext="{Binding RelativeSource={RelativeSource Self}}">
    <Grid>
        <ListView Name="DocsListView" ItemsSource="{Binding Data}">
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="Documents" DisplayMemberBinding="{Binding Documents}"/>
                </GridView>
            </ListView.View>
        </ListView>
    </Grid>
</Window>

C# Code-Behind (ObservableCollection refreshes the UI automatically if a Item gets added or deleted):

public ObservableCollection<YourEntity> Data
{
     get { return (ObservableCollection<YourEntity>)GetValue(DataProperty); }
     set { SetValue(DataProperty, value); }
}

// Using a DependencyProperty as the backing store for Data.  This enables animation, styling, binding, etc...
public static readonly DependencyProperty DataProperty =
DependencyProperty.Register("Data", typeof(ObservableCollection<YourEntity>), typeof(MainWindow), null);

public void LoadDocs()
{
     Context _Context = new Context();
     if(Data == null)
     {
         Data = new ObservableCollection<YourEntity>();
     }
     else
     {
         Data.Clear();
     }
     foreach(var doc in _Context.SP_GetDocuments(1).ToList())
     {
         Data.Add(doc);
     }
     _Context = null;
}

Upvotes: 3

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