Question

我使用Xamarin Forms v2.3.1.114，我想在我的应用程序中创建一个调查页面。

我的基础课是：

public class Question
{
    public string Title { get; set; }
    public List<string> Answers { get; set; }
}

我的示例代码是：

ObservableCollection<Question> Questions = new ObservableCollection<Question> ();

        Questions.Add (
            new Question () {
                Title = "Question A",
                Answers = new List<string>{
                        "Answer A",
                        "Answer B",
                        "Answer C",
                        "Answer D"
                        }
            }
         );

        Questions.Add (
            new Question () {
                Title = "Question B",
                Answers = new List<string>{
                        "Answer A",
                        "Answer B",
                        "Answer C",
                        "Answer D",
                        "Answer E",
                        "Answer F"
                }
            }
         );

我的Xaml如下：

<Grid Grid.Row="1">

        <cv:CarouselView x:Name="CarouselQuestions">
        <cv:CarouselView.ItemTemplate>
        <DataTemplate>
            <Grid Padding="12">
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"/>
                <RowDefinition Height="*"/>     
            </Grid.RowDefinitions>
            <Grid Grid.Row="0" BackgroundColor="#404040">
                <ContentView Padding="12">
                        <Label TextColor="White" HorizontalOptions="Start" Text="{Binding Title}"/>
                </ContentView>
            </Grid>
                <ListView Grid.Row="1" ItemsSource="{Binding Answers}" BackgroundColor="Transparent" HasUnevenRows="true">
                    <ListView.ItemTemplate>
                        <DataTemplate>
                            <ViewCell>
                                <Grid Padding="12">
                                <Label TextColor="Black" Text="{Binding}"/>
                                </Grid>
                            </ViewCell>
                        </DataTemplate>
                    </ListView.ItemTemplate>
                </ListView>         
            </Grid>
        </DataTemplate>
        </cv:CarouselView.ItemTemplate>
        </cv:CarouselView>

</Grid>

我使用Nuget的CarouselView控件但是当我从一个列表视图中选择一个值并滑动轮播时，所选的值已经丢失。

我该如何解决这个问题？

谢谢!!

Answer 1

由于重复使用Carousel项目，您必须更新所选项目或将其绑定到CarouselView项目的新属性中，您需要添加以下内容：

object _selectedItem;
public object SelectedItem{
    get{
       return _selectedItem;
    }
    set{
        _selectedItem = value;
        OnPropertyChanged();
    }
}

并将绑定添加到ListView Xaml

<ListView SelectedItem="{Binding SelectedItem}" Grid.Row="1" ItemsSource="{Binding Answers}" BackgroundColor="Transparent" HasUnevenRows="true">

Xamarin表格轮播查看丢失的选定值（调查样本）

1 个答案: