Question

我一直在寻找所有可能性，但仍然找不到我的代码出了什么问题。让我解释一下：我有一个由Datatemplate选择器和2 dataTemplate引导的旋转木马视图，第一个显示在第一页，第二个显示在第二个旋转木马页面。在此数据模板内部，我得到了一个永远不会填充的ListView。我知道ListView在这里，因为当我尝试刷新的位置应该刷新刷新指示器。首先，我认为这是因为绑定，但是即使没有绑定，也只是一个文本单元，同样的问题，什么也不会显示。

这是我的代码：XAML

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:TestDappli"
             xmlns:sys="clr-namespace:System;assembly=mscorlib" 
            xmlns:control="clr-namespace:Xamarin.Forms;assembly=Xamarin.Forms.CarouselView"
             xmlns:testCarouselView="clr-namespace:TestDappli;assembly=TestDappli"
             BackgroundColor="White"
             x:Name="Mapage"
             x:Class="TestDappli.MainPage">
    <ContentPage.Resources>
        <ResourceDictionary>
            <!--Singapour template-->
            <DataTemplate x:Key="Singapour">
                <StackLayout Orientation="Vertical" Padding="30" Spacing="40" BackgroundColor="White" >
                    <Label Text="Singapour"
                           HorizontalOptions="CenterAndExpand"/>
                    <Label Text="Date :"
               VerticalOptions="Start"/>
                    <DatePicker HorizontalOptions="Center"
                    Date="{x:Static sys:DateTime.Now}">
                        <DatePicker.Format>dd-MM-yyyy</DatePicker.Format>
                        <DatePicker.MinimumDate>
                            <sys:DateTime x:FactoryMethod="Parse">
                                <x:Arguments>
                                    <x:String>Jan 1 2000</x:String>
                                </x:Arguments>
                            </sys:DateTime>
                        </DatePicker.MinimumDate>
                        <DatePicker.MaximumDate>
                            <sys:DateTime x:FactoryMethod="Parse">
                                <x:Arguments>
                                    <x:String>Dec 31 2050</x:String>
                                </x:Arguments>
                            </sys:DateTime>
                        </DatePicker.MaximumDate>
                    </DatePicker>
                    <Label Text="Dispo :"/>
                    <ListView x:Name="HoraireViewSingapour"
                  IsPullToRefreshEnabled="True"
                  Refreshing="ListItems_Refreshing"
                  ItemSelected="OnSelection">
                        <ListView.ItemTemplate>
                            <DataTemplate>
                                <TextCell Text="SHOULD BE TEXT1" TextColor="DarkOrange" Detail="BUT THERE IS NOTHING HERE" />
                            </DataTemplate>
                        </ListView.ItemTemplate>
                    </ListView>
                </StackLayout>
            </DataTemplate>

            <!--Bangalor template-->
            <DataTemplate x:Key="Bangalor">
                <StackLayout Orientation="Vertical" Padding="30" Spacing="40" BackgroundColor="White" >
                    <Label Text="Bangalor"
                         HorizontalOptions="CenterAndExpand"/>
                    <Label Text="Date :"
               VerticalOptions="Start"/>
                    <DatePicker HorizontalOptions="Center"
                    Date="{x:Static sys:DateTime.Now}">
                        <DatePicker.Format>dd-MM-yyyy</DatePicker.Format>
                        <DatePicker.MinimumDate>
                            <sys:DateTime x:FactoryMethod="Parse">
                                <x:Arguments>
                                    <x:String>Jan 1 2000</x:String>
                                </x:Arguments>
                            </sys:DateTime>
                        </DatePicker.MinimumDate>
                        <DatePicker.MaximumDate>
                            <sys:DateTime x:FactoryMethod="Parse">
                                <x:Arguments>
                                    <x:String>Dec 31 2050</x:String>
                                </x:Arguments>
                            </sys:DateTime>
                        </DatePicker.MaximumDate>
                    </DatePicker>
                    <Label Text="Dispo :"/>
                    <ListView x:Name="HoraireViewBangalor"
                  IsPullToRefreshEnabled="True"
                  Refreshing="ListItems_Refreshing"
                  ItemSelected="OnSelection">
                        <ListView.ItemTemplate>
                            <DataTemplate>
                                <TextCell Text="SHOULD BE SOME TEXT HERE " TextColor="DarkOrange" Detail="BUT THERE IS NOT" />
                            </DataTemplate>
                        </ListView.ItemTemplate>
                    </ListView>
                </StackLayout>
            </DataTemplate>
            <!--Template selector-->
            <testCarouselView:CarouselTemplateSelector x:Key="CarouselTemplateSelector" 
                Singapour="{StaticResource Singapour}" 
                Bangalor="{StaticResource Bangalor}" />
        </ResourceDictionary>
    </ContentPage.Resources>
    <control:CarouselView
        x:Name="MyCarouselView" 
        HorizontalOptions="FillAndExpand" 
        VerticalOptions="FillAndExpand" 
        ItemTemplate="{StaticResource CarouselTemplateSelector}"
          >
    </control:CarouselView>
</ContentPage>

然后输入后面的代码：

public partial class MainPage : ContentPage
    {
        public ObservableCollection<Creneau> List = new ObservableCollection<Creneau>();
        public ObservableCollection<Salle> Salle = new ObservableCollection<Salle>();



        public MainPage()
        {
            BindingContext = this;
            CreateList();
            InitializeComponent();
            this.MyCarouselView.ItemsSource = Salle;
            doRefresh();
        }

        public async void OnSelection(object sender, SelectedItemChangedEventArgs e)
        {
            if (e.SelectedItem == null)
            {
                return;
            }
            else
            {
                var answer = await DisplayAlert("Reservation", "Voulez vous reserver la salle SALLE de " + ((Creneau)e.SelectedItem).start + "h à " + ((Creneau)e.SelectedItem).end + "h", "Yes", "No");
                if (answer)
                {
                    ChangeOccupe((Creneau)e.SelectedItem);
                }
            }
        }
        protected void ListItems_Refreshing(object sender, EventArgs e)
        {
            doRefresh();
          ((ListView)sender).EndRefresh();
        }

        protected void doRefresh()
        {

        }
        protected void CreateList()
        {
            for (int i = 8; i < 20; i++)
            {
                Creneau cr = new Creneau("Libre", i, i + 1);
                List.Add(cr);
            }
            Salle BangalorS = new Salle("Bangalor", List);
            Salle.Add(BangalorS);
            Salle SingapourS = new Salle("Singapour", List);
            Salle.Add(SingapourS);
        }
        protected void ChangeOccupe(Creneau c)
        {
            foreach (Creneau cre in List)
            {
                if (c.Equals(cre))
                {
                    if (cre.VarOccupe == "Libre")
                    {
                        cre.VarOccupe = "Reservée";
                    }
                    else
                    {
                        cre.VarOccupe = "Libre";
                    }
                }
            }

        }

    }

这是轮播的templateSelector：

public class CarouselTemplateSelector : DataTemplateSelector
{
    public DataTemplate Singapour { get; set; }
    public DataTemplate Bangalor { get; set; }
    protected override DataTemplate OnSelectTemplate(object item, BindableObject container)
    {
        Salle salle = (Salle)item;
        switch (salle.name)
        {
            case "Singapour":
                return Singapour;
            case "Bangalor":
                return Bangalor;
            default:
                throw new ArgumentOutOfRangeException();
        }
    }
}

萨尔和克雷诺都

   public class Salle
    {
        public string name;
        public ObservableCollection<Creneau> list = new ObservableCollection<Creneau>();
        public Salle(string name, ObservableCollection<Creneau> cren)
         { 
            this.name = name;
            list = cren;
        }
    }



public class Creneau : INotifyPropertyChanged
    {
        private string occupe;
        public string VarOccupe
        {
            get
            {
                return occupe;
            }
            set
            {
                occupe = value;
                OnPropertyChanged("VarOccupe");
            }
        }
        public event PropertyChangedEventHandler PropertyChanged;

        public int start { get; set; }
        public int end { get; set; }
        public string creneau { get; set; }
        public Creneau(string occuper,int start, int end)
        {
            this.end = end;
            this.occupe = occuper;
            this.start = start;
            creneau = start.ToString() + "h " + "- " + end.ToString() + "h :";
        }

        private void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

如果您对问题有任何想法，我会接受所有建议，我尝试了2天。预先谢谢

[编辑]我尝试了使用TableView的情况，它可能来自列表视图中的datatemplate吗？我的意思是我看不到任何地方都无法将DataTemplate放入DataTemplate

Answer 1

您的页面缺少INotifyPropertyChanged接口。

public partial class MainPage : ContentPage, INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public ObservableCollection<Creneau> _list;

    public ObservableCollection<Creneau> List
    {
        get 
        {
            return _list;
        }
        set 
        {
            _list = value; 
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("List"));
        }
    }
//    ....

CarouselView中的ListView存在但为空

1 个答案: