UI not updating despite ObservableCollection (UWP, XAML)

Question

I would greatly appreciate some help with this binding issue I'm having. Basically I have a list view showing some information about Files. In the list view item itself, there's some text and also a button.

When this button is clicked I want to disable that button.

Currently I've set up an ObservableCollection - however even though the button click is being registered, the UI doesn't update. If I go to a different screen and return, then the UI updates. So it's not instantaneous.

I think there is some problem with the way RaisePropertyChanged() is working. I know from reading other SO articles that property changes in the object are harder to pick up than say, removing an item or adding an item to the ListView.

I'm completely stuck, any help would be most appreciated. Thanks.

Xaml:

<ListView RelativePanel.Below="heading" ItemsSource="{Binding Pages}" ReorderMode="Enabled" CanReorderItems="True" AllowDrop="True" Margin="0,10" SelectedItem="{Binding Path=SelectedFile,Mode=TwoWay}" >
    <ListView.ItemTemplate>
        <DataTemplate x:DataType="model:File">
            <Grid Padding="10">
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto"/>
                    <RowDefinition Height="Auto"/>
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="250"/>
                    <ColumnDefinition Width="Auto"/>
                </Grid.ColumnDefinitions>
                <TextBlock Text="{x:Bind Path= Name, Mode=TwoWay}" FontWeight="Bold" Padding="0,5"  />
                <TextBlock Text ="{x:Bind Path}" Grid.Row="1" TextWrapping="Wrap" Padding="10,0,0,0" Foreground="DarkGray" Opacity="0.8" />
                <Button Content="X" Grid.Column="1" Grid.RowSpan="2" Command="{x:Bind EnableCommand}" IsEnabled="{x:Bind Path=IsEnabled, Mode=OneWay}" />
            </Grid>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

File.cs:

public class File : ViewModelBase
{
    public string Name { get; set; }
    public string FileName { get; set; }
    public string Path { get; set; }
    public string Contents { get; set; }

    private Boolean isEnabled = true;
    public Boolean IsEnabled {
        get { return isEnabled; }
        private set {
            isEnabled = value;
            RaisePropertyChanged("IsChecked");
        }
    }

    private ICommand enableCommand;
    public ICommand EnableCommand
    {
        get
        {
            if(enableCommand == null)
            {
                enableCommand = new RelayCommand(() => {
                    isEnabled = false;
                    Name += "Disabled";
                    RaisePropertyChanged();
                });
            }

            return enableCommand;
        }
    }
}

Viewmodel:

public class MyPageViewModel : BaseViewModel
{
    private ObservableCollection<File> pages;

    public ObservableCollection<File> Pages
    {
        get { return pages; }
        set
        {
            pages = value;
            RaisePropertyChanged();
        }
    }

    private File selectedFile = new File();
    public File SelectedFile
    {
        get { return selectedFile; }
        set
        {
            Set(ref selectedFile, value);
        }
    }

    public MyPageViewModel()
    {
        if (ApplicationData.FileList != null)
        {
            Pages = new ObservableCollection<File>(ApplicationData.FileList);
        }

        else
        {
            Pages = new ObservableCollection<File>();
        }
    }

score 1 · Answer 1 · edited Aug 11 '16 at 05:47

1

You notify IsChecked when you should be notifying IsEnabled.

(ObsevarvableCollection only notifies when something is added or removed from it. Changes in the objects it holds are not notified by it.)

edited Aug 11 '16 at 05:47

neer

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answered Aug 11 '16 at 04:15

aksu

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UI not updating despite ObservableCollection (UWP, XAML)

1 Answers1