Data binding auto update question

Question

I cannot get it working. I bind a list of FileCategory to a ComboBox.ItemsSource (OneWay mode), but when I add new items to the list, the ComboBox won't get update accordingly.

class FileCategory
{
    public string Name { get; set; }
    public string Description { get; set; }
}

internal IList<FileCategory> Categories = new List<FileCategory>
{
        new FileCategory { Name = "aaa", Description = "aaa item" },
        new FileCategory { Name = "bbb", Description = "bbb item" },
        new FileCategory { Name = "ccc", Description = "ccc item" },
};

private void Button_Click(object sender, RoutedEventArgs e)
{
    var name = "new#" + Categories.Count;
    Categories.Add(new FileCategory { Name = name, Description = name + " item" });
}

Categories.Add(new FileCategory { Name = name, Description = name + " item" });

<ComboBox x:Name="combo1"
          ItemsSource="{x:Bind Categories, Mode=OneWay}"
          SelectedValuePath="Name">

Answer 1

Hi @杨岑 ,

Welcome to Microsoft Q&A!

It is recomended to use ObservableCollection, it provides notifications when items get added or removed, or when the whole list is refreshed.

   ObservableCollection<FileCategory> Categories = new ObservableCollection<FileCategory>
   {
       new FileCategory { Name = "aaa", Description = "aaa item" },
       new FileCategory { Name = "bbb", Description = "bbb item" },
       new FileCategory { Name = "ccc", Description = "ccc item" },
   };

Thank you.

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