使用Xamarin.Forms轮播视图显示ListView的列表，每个列表包含对象列表

Question

im using Xamarin.Forms and im having a problem trying to use alexrainman's Carousel View .

Particularly, i want to set up a Carousel View in which each view is a ListView , and then each ListView would display a List of objects.

I have read through the document pages and define the sources for my CarouselView and ListView as follow:

ObservableCollection<ObservableCollection<ItemFormat>> MyCarouselSource = new ObservableCollection<ObservableCollection<ItemFormat>>();

 ObservableCollection<ItemFormat> MyListViewSource = new ObservableCollection<ItemFormat>();

but i can not get it to work.

My ListView would have a list of objects, something like this:

[
{
"field_name":"value1",
"field_value":"value11"
},
{
"field_name":"value2",
"field_value":"value22"
},
...
]

Here is my code:

 public class ItemFormat
    {
        [JsonProperty("field_name")]
        public string FieldName { get; set; }

        [JsonProperty("field_value")]
        public string FieldValue { get; set; }
    }

View Model (ValidationBindableBase has the INotifyPropertyChanged in it):

 public class MyViewModel : ValidationBindableBase
    {
...
        ObservableCollection<ObservableCollection<ItemFormat>> _myCarouselSource;
        public ObservableCollection<ObservableCollection<ItemFormat>> MyCarouselSource
        {
            get => _myCarouselSource;
            set => SetProperty(ref _myCarouselSource, value);
        }


        ObservableCollection<ItemFormat> _myListViewSource;
        public ObservableCollection<ItemFormat> MyListViewSource
        {
            get => _myListViewSource;
            set => SetProperty(ref _myListViewSource, value);
        }
   public DetailedSalaryViewModel()
        {
        }
    }

code behind

public partial class MyViewPage : ContentPage
    {
        MyViewModel viewModel = new MyViewModel();
        public MyViewPage ()
        {
            InitializeComponent ();
            BindingContext = viewModel ;
        }
    }

The XAML view:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage
    x:Class="salary_sheet.Views.MyViewPage"
    xmlns="http://xamarin.com/schemas/2014/forms"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:controls="clr-namespace:CarouselView.FormsPlugin.Abstractions;assembly=CarouselView.FormsPlugin.Abstractions">
    <controls:CarouselViewControl
        x:Name="carousel"
        ItemsSource="{Binding MyCarouselSource}"
        Orientation="Horizontal"
        ShowArrows="true"
        ShowIndicators="true">
        <controls:CarouselViewControl.ItemTemplate>
            <DataTemplate>
                <ListView ItemsSource="{Binding MyListViewSource}" RowHeight="100">
                    <ListView.ItemTemplate>
                        <DataTemplate>
                            <ViewCell>
                                <Grid Padding="5">

                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width=".5*" />
                                        <ColumnDefinition Width=".5*" />
                                    </Grid.ColumnDefinitions>

                                    <Label
                                        Grid.Column="0"
                                        HorizontalOptions="Start"
                                        Text="{Binding FieldName}" />
                                    <Label
                                        Grid.Column="1"
                                        HorizontalOptions="Start"
                                        Text="{Binding FieldValue}" />
                                </Grid>
                            </ViewCell>
                        </DataTemplate>
                    </ListView.ItemTemplate>
                </ListView>
            </DataTemplate>
        </controls:CarouselViewControl.ItemTemplate>
    </controls:CarouselViewControl>
</ContentPage>

Please help me to correct the definition of the sources for my ListView and CarouselView.

Also how to establish and organize the view's XAML code.

I really appreciate all help. Thank you.

Answer 1

What exactly do you get as an error? Have you tried wrapping your ListView in some root layout like ContentView or StackLayout.

Code-behind and ViewModel implementation both look okay, so I guess it is only problem with parsing the XAML.

So, try to do something like this with your XAML view:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage
    x:Class="salary_sheet.Views.MyViewPage"
    xmlns="http://xamarin.com/schemas/2014/forms"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:controls="clr-namespace:CarouselView.FormsPlugin.Abstractions;assembly=CarouselView.FormsPlugin.Abstractions">
    <controls:CarouselViewControl
        x:Name="carousel"
        ItemsSource="{Binding MyCarouselSource}"
        Orientation="Horizontal"
        ShowArrows="true"
        ShowIndicators="true">
        <controls:CarouselViewControl.ItemTemplate>
            <DataTemplate>
                <ContentView>
                    <ListView ItemsSource="{Binding MyListViewSource}" RowHeight="100">
                       <ListView.ItemTemplate>
                           <DataTemplate>
                               <ViewCell>
                                   <Grid Padding="5">

                                       <Grid.ColumnDefinitions>
                                           <ColumnDefinition Width=".5*" />
                                           <ColumnDefinition Width=".5*" />
                                       </Grid.ColumnDefinitions>

                                       <Label
                                           Grid.Column="0"
                                           HorizontalOptions="Start"
                                           Text="{Binding FieldName}" />
                                       <Label
                                           Grid.Column="1"
                                           HorizontalOptions="Start"
                                           Text="{Binding FieldValue}" />
                                   </Grid>
                               </ViewCell>
                           </DataTemplate>
                       </ListView.ItemTemplate>
                   </ListView>
                </ContentView>
            </DataTemplate>
        </controls:CarouselViewControl.ItemTemplate>
    </controls:CarouselViewControl>
</ContentPage>