WPF ItemsControl binding issue

Question

I have problem with Binding: see my code

This is Xaml code:

<ItemsControl x:Name="lbOpenInvoices" ItemsSource="{Binding Path=ocOpenInvoices}">
<ItemsControl.ItemsPanel>
    <ItemsPanelTemplate>
        <UniformGrid Columns="3" VerticalAlignment="Top" />
    </ItemsPanelTemplate>
</ItemsControl.ItemsPanel>

<ItemsControl.ItemTemplate>
    <DataTemplate>
        <Button x:Name="btnOpenInvoice" Click="btnOpenInvoice_Click" Style="{StaticResource OpenInvoicesButton}">
            <StackPanel Orientation="Vertical">
                <TextBlock Text="{Binding Converter={StaticResource InvoiceNoTableNo}}"/>
                <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
                    <TextBlock Text="{Binding Converter={StaticResource InvoiceNoInvoiceId}}"/>
                    <TextBlock Text="{Binding TotalAmount}" FontSize="14" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                </StackPanel>
                <TextBlock Text="{Binding Converter={StaticResource InvoiceDateTime}}"/>
            </StackPanel>
        </Button>
    </DataTemplate>
</ItemsControl.ItemTemplate>

In Code behind I have declared the ocOpenInvoices ObservableCollection:

        public ObservableCollection<Invoice> ocOpenInvoices { get; set; }

And In my Window Loadded event:

        void SaleWindow_Loaded(object sender, RoutedEventArgs e)
        {
          this.DataContext = this;
        }

But It driving me Crazy because the ItemControl does not respond to ocOpenInvoices ObservableCollection.

When I give it the ItemsSource from codebehind it works :(, I have tried to give it the ElementName but it still not respond.

Please can you help and tell me what's my problem? what I miss here? Thanks in advance.

When are you creating the ocOpenInvoices? before of after the `InitializeComponent();` The binding could be done before you created it. So it binds on NULL. — Jeroen van Langen, Apr 06 '14 at 11:01
This all seems to work (at least in a small example using a single Window class), are you able to recreate the problem in a small example project? — Chris, Apr 06 '14 at 11:58

Mayur Dhingra · Accepted Answer · 2014-04-07T04:44:10.853

5

Try abstracting your observable collection over a private variable a private, it will work.

Replace

public ObservableCollection<Invoice> ocOpenInvoices { get; set; }

with

private ObservableCollection<Invoice> _ocOpenInvoices;
public ObservableCollection<Invoice> ocOpenInvoices
{ 
  get { return _ocOpenInvoices ; } 
  set { _ocOpenInvoices = value; OnPropertyChange("ocOpenInvoices"); }
}

Please ignore this OnPropertyChange, if you have already implemented INotifyPropertyChanged in your own way, otherwise, it would be INotifyPropertyChanged that can solve your issue.

edited Apr 07 '14 at 04:44

answered Apr 06 '14 at 14:24

Mayur Dhingra

1,527
10
27

This is the right answer. Here's a link that might help too. http://msdn.microsoft.com/en-us/library/ms743695(v=vs.110).aspx – FodderZone Apr 06 '14 at 14:39

score 1 · Answer 2 · answered Apr 06 '14 at 16:40

Make sure you initialize your ObservableCollection within Window's constructor or Window loaded event.

void SaleWindow_Loaded(object sender, RoutedEventArgs e)
{
   ocOpenInvoices = new ObservableCollection<Invoice>();
   this.DataContext = this;
}

If you are initializing it somewhere else than make sure you implement INotifyPropertyChanged and raise PropertyChanged.

WPF ItemsControl binding issue

2 Answers2