How to update UI according to ObservableCollection in WPF

Question

I have this MVVM project, and there an ObservableCollection. To that collection I store some information. Now, based on that info in the collection, I want to create "blocks" into my UI.

private ObservableCollection<Input> _inputlist;

public ObservableCollection<Input> iinputlist
{
    get
    {
        if (_inputlist == null)
        {
            _inputlist = new ObservableCollection<Input>();
        }
        return _inputlist;
    }
}

ObservableCollection works fine and I got there the info what I need. The information to the collection comes from external file (XML), which I read through. There could be few hundred "items" in it. I want to create one block for each item in the collection.

Now I have this XAML code:

<s:Toolbox x:Key="InputBlocks" ItemSize="80,75">
    <ListBox ItemTemplate="{Binding Source={StaticResource ItemsTemplate}}"
             ItemsSource="{Binding Source={StaticResource xml}, Path=iinputlist, UpdateSourceTrigger=PropertyChanged}">
    </ListBox>
</s:Toolbox>

Here I try to create those "blocks" inside a listbox, based on the information what's in the ObservableCollection. The ItemTemplate for the blocks works fine (tried with some hardcoded stuff).

For some reason, my GUI is not updated, and the blocks won't show in the listbox. With my understanding, ObservableCollection does include "OnPropertyChanged" in itself, so that shouldn't be a problem.

I also tried the binding with the following (replaced the listbox -part with this):

<ItemsControl.Items>
        <ItemsControl Name="inputit"
                      Style="{StaticResource ItemsTemplate}"
                      ItemsSource="{Binding Path=iinputlist, UpdateSourceTrigger=PropertyChanged}"/>
</ItemsControl.Items>

But still no update in GUI. What am I missing? I have a feeling, the problem has something to do with the binding, but I haven't figured out what's wrong. Thanks for the tips in advance.

Binding Source={StaticResource xml} where is this resource defined?? — Abhinav Sharma, Jul 18 '16 at 09:22
Hmm. I see I haven't set the DataContext. Where should I set it? I have the Window1.xaml (and xaml.cs), XmlWorker.cs and InputBlocks.xaml, and some other, but they are not relevant with this. — J. Niinisalo, Jul 18 '16 at 09:43
The window where the ListBox is set the dataContext to xmlWorker.cs, then set ItemsSource="{Binding Path=iinputlist, UpdateSourceTrigger=PropertyChanged}". This should work. — Abhinav Sharma, Jul 18 '16 at 09:51
Can I set the DataContext even though that xaml file is ResourceDictionary? Or should I create different kind of file? — J. Niinisalo, Jul 18 '16 at 11:14
Where is your iinputlist Collection.You can set that file as datacontext. — Abhinav Sharma, Jul 18 '16 at 11:19
http://stackoverflow.com/questions/23713898/setting-datacontext-in-xaml-in-wpf — Abhinav Sharma, Jul 18 '16 at 11:20
http://stackoverflow.com/questions/28315697/setting-the-datacontext-to-the-current-code-behind-object-in-xaml — Abhinav Sharma, Jul 18 '16 at 11:20

How to update UI according to ObservableCollection in WPF

0 Answers0