CODEWITHSUNDEEP
c#xamlxamarin.formsobservablecollection
Lucas Angelo
Lucas Angelo

Reputation: 13

C# (Xamarin) - How to access an object attribute from an "ObservableCollection<T>"?

I have this function that create an ObservableCollection<MenuBody> to create my Xamarin.Forms user menu.

    private ObservableCollection<MenuBody> _userList;
    public ObservableCollection<MenuBody> UserList
    {
        set { SetProperty(ref _userList, value); }
        get { return _userList; }
    }

    private void LoadUserMenu()
    {
        UserList = new ObservableCollection<MenuBody>
        {
            new MenuBody
            {   
                Id = 1,
                Text = "Principal",
                Icon = IconFont.FileSignature,
            },
            new MenuBody
            {
                Id = 2,
                Text = "Configurações",
                Icon = IconFont.Cog,
            },
        };
    }

XAML CollectionView bind properties:

<CollectionView 
    x:Name="MyUserCollectionView"
    BackgroundColor="Transparent" 
    ItemsSource="{Binding UserList}"
    SelectionMode="Single"
    SelectionChangedCommand="{Binding MenuUserTappedCommand}" 
    SelectionChangedCommandParameter="{Binding SelectedItem, 
                                       Source{x:ReferenceMyUserCollectionView}}"

Function that I'm using to detect the user tap on menu.

     private DelegateCommand<object> _menuUserTappedCommand;

     public DelegateCommand<object> MenuUserTappedCommand =>
    _menuUserTappedCommand ?? (_menuUserTappedCommand = new DelegateCommand<object>(ExecuteMenuUserTappedCommand));

async void ExecuteMenuUserTappedCommand(object parameter)
{
    await App.Current.MainPage.DisplayAlert("Message", "Item " + parameter + " clicked", "Ok");
}

And I'm trying to access the MenuBody Id attribute from here:

enter image description here

I tried to write as parameter.Id to reference it, but it doesn't appear as expected.

enter image description here

Can anyone help me find out where I'm wrong?

Upvotes: 0

Views: 193

Answers (1)

Jason
Jason

Reputation: 89117

either cast it

var item = (MenuBody)parameter;
// then you can use item.Id

or use the correct type instead of object

public DelegateCommand<MenuBody> MenuUserTappedCommand =>
_menuUserTappedCommand ?? (_menuUserTappedCommand = new DelegateCommand<MenuBody>(ExecuteMenuUserTappedCommand));

async void ExecuteMenuUserTappedCommand(MenuBody parameter)
{
    await App.Current.MainPage.DisplayAlert("Message", "Item " + parameter.Id + " clicked", "Ok");
}

Upvotes: 1

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