CODEWITHSUNDEEP
c#wpfxamllistviewcollectionviewsource
RLH
RLH

Reputation: 15698

Adding records to a CollectionViewSource resource, not showing up in a bound ListView

First, this is my first attempt at using WPF. I'll try to spare as much information as possible, since this data-entry form is a little less than typical. However, if more information is needed, please ask.

I have a WPF window with a series of CollectionViewSource objects in my Window.Resources collection. These are initialized in my window's constructor.

One of these collections is an IList<T> where T is of a POCO type used with Entity Framework.

My form has a section of user-input controls. When the user hits the Save button, I need to create an entity and add it to my IList collection.

So far, I've had no trouble. I can create the entity, and I can add it to the collection without any issue. However, the problem is that I have a ListView control that is bound to this collection. I can, and have verified, that I can load records to this list when the Window initializes in the constructor. However, when I click my Save button, the collection gets updated, but the UI does not refresh the operation.

For reference, here is the pertinent code below.

SetResource() - Called in the constructor of my Window

    private void SetResources()
    {
        ... other objects...

        //myCacheSrc is property defined in my Window.cs file.
        myCacheSrc = (CollectionViewSource)FindResource("myCacheSrc");
        myCacheSrc.Source = new List<MyEFPOCO>();

        ... more initializations of other objects.
    }

Contents of my Save button click event

    private void Save_Click(object sender, RoutedEventArgs e)
    {
        var cache = myCacheSrc.Source as List<MyEFPOCO>;
        if (cache != null && !CurrentRecord.Equals(origCurrentRecord))
        {
            cache.Add(CurrentRecord);
        }
    }

It is worth mentioning, I've stepped through the above block of code. It is executing on the save event, and the CurrentRecord property does contain a valid entity.

Here is a my Window constructor. Notice that there is a test insert operation. This works! Note, it's not much different than the code in my button event. Why would this work, and not the button event?

Window Constructor

    public MyWindow()
    {
        InitializeComponent();
        SetResources();

        //TEST
        var cache = myCacheSrc.Source as List<MyEFPOCO>;
        if (cache != null)
        {
            cache.Add(new MyEFPOCO
                { 
                    userEntryType = "TEST",
                    numberValue= 1234567
                });
        }
    }

MyWindow.xaml - Declaration of the ListView in question

        <ListView Name="CachedChangesList" ItemsSource="{Binding Source={StaticResource myCacheSrc}}">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <DockPanel>
                        <Button Name="UpdateChange" Content="{StaticResource iUpdate}" Width="20" />
                        <Button Name="DeleteChange" Content="{StaticResource iDelete}" Width="20" />
                        <Label Content="{Binding userEntryType}" />
                        <Label Content="{Binding numberValue}" />
                    </DockPanel>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>

Upvotes: 0

Views: 566

Answers (1)

Ayyappan Subramanian
Ayyappan Subramanian

Reputation: 5366

Use ObservableCollection Instead of List, Because it will notify the UI about the source change. https://msdn.microsoft.com/en-us/library/ms668604(v=vs.110).aspx

 myCacheSrc = (CollectionViewSource)FindResource("myCacheSrc");
        myCacheSrc.Source = new ObservableCollection<MyEFPOCO>();

Upvotes: 2

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