Updating ObservableCollection in CollectionView

Question

Hi, I am using CollectionView to display a list of ObservableCollection<BindableItems>, the objects are updated with any changes every 15 seconds through a HTTP GET request.

However, when updating the Object properties in the ObservableCollection, the changes were not updated in the UI.

As a solution, I made all the properties inside the BindableItems use a SetProperty function from MvvmHelpers which inherits from INotifyPropertyChanged.

Then when I reassign the properties of the existing BindableItem objects, the UI is updated too.

I am new to Xamarin and I am used to working with Vue where reactivity is mostly taken care of for you. I wonder if my approach/solution is correct especially from a performance standpoint as I am updating a list of 100 or more objects which have 10 properties each every 15 seconds. Is this the recommended way? :)

An alternative I can think of would be to just clear the list and reinsert new objects but that seems wasteful.

Thanks

Answer 1

Hello,​

Welcome to our Microsoft Q&A platform!

An alternative I can think of would be to just clear the list and reinsert new objects but that seems wasteful.

After creating a ViewModel class and setting BindingContext for the page, please make sure the data collection you want to update is from the bindingContext.

Check the following code:

   public partial class TestPage : ContentPage  
   {  
       TestPageViewModel viewModel;  
       public TestPage()  
       {  
           InitializeComponent();  
     
           viewModel = new TestPageViewModel();  
           BindingContext = viewModel;  
       }  
     
       private async void Button_Clicked(object sender, EventArgs e)  
       {  
           //update the data  
           viewModel.BindableItems.Add(new BindableItem{ ... });  
       }  
   }  
     
   public class TestPageViewModel  
   {  
       public ObservableCollection<BindableItem> BindableItems { get; set; }  
       public TestPageViewModel()  
       {  
           DataCollection = new ObservableCollection<BindableItem>();  
           //add the data  
       }  
   }  

Best Regards,

Jarvan Zhang

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