c# - 如何从另一个类中删除 ListView 项

Question

对于我的 Tizen .net Wearable 应用程序，我希望能够在按下/切换复选图标时删除 ListView 项。然而，问题在于检查元素在 CustomClass 中，而 ListView 在 AppClass 中。

我试过将 check 元素设为全局，但不幸的是没有成功。

namespace TizenWearableApp5
{
    public class App : Application
    {
        public App()
        {
            // The root page of your application
            CirclePage circlePage = new CirclePage();
            CircleListView listView = new CircleListView();
            listView.ItemTemplate = new DataTemplate(typeof(CustomCell));
            listView.ItemsSource = getTasks.Taken;
            listView.HasUnevenRows = true;
            MainPage = circlePage;
            circlePage.Content = listView;
            CustomCell.check.Toggled += (s, e) =>
            {

            };
        }
    }

    public class Taken
    {
        public string Name { get; set; }

        public string Team { get; set; }
    }

    public class CustomCell : ViewCell
    {
        public static Check check = new Check();
        public ObservableCollection<TaskViewModel> Taken { get; set; }
        public CustomCell()
        {
            Taken = new ObservableCollection<TaskViewModel>();
            StackLayout cell = new StackLayout()
            {
                HeightRequest = 120,
                HorizontalOptions = LayoutOptions.FillAndExpand,
                Orientation = StackOrientation.Horizontal,
                VerticalOptions = LayoutOptions.FillAndExpand,
                WidthRequest = 360,
            };
            StackLayout left = new StackLayout()
            {
                HorizontalOptions = LayoutOptions.CenterAndExpand,
                Orientation = StackOrientation.Vertical,
                VerticalOptions = LayoutOptions.Center,
            };
            Label name = new Label()
            {
                FontSize = 8,
                HorizontalOptions = LayoutOptions.Center,
                HorizontalTextAlignment = TextAlignment.Center,
                VerticalOptions = LayoutOptions.Center,
                VerticalTextAlignment = TextAlignment.Center,
            };

            Label team = new Label()
            {
                FontSize = 5,
                HorizontalOptions = LayoutOptions.Center,
                HorizontalTextAlignment = TextAlignment.Center,
                VerticalOptions = LayoutOptions.Center,
                VerticalTextAlignment = TextAlignment.Center,
            };
            check.DisplayStyle = CheckDisplayStyle.Default;
            check.HorizontalOptions = LayoutOptions.End;
            check.VerticalOptions = LayoutOptions.Center;

            //Set Binding
            name.SetBinding(Label.TextProperty, new Binding("Name"));
            team.SetBinding(Label.TextProperty, new Binding("Team"));
            View = cell;
            cell.Children.Add(left);
            left.Children.Add(name);
            left.Children.Add(team);
            cell.Children.Add(check);
        }
    }

    public static class getTasks
    {
        public static IList<Taken> Taken { get; set; }

        static getTasks()
        {
            Taken = new ObservableCollection<Taken>() {
                new Taken
                {
                    Name = "Martin",
                    Team = "Red"
                },
                new Taken
                {
                    Name = "John",
                    Team = "Blue"
                }
            };
        }
    }
}

我希望能够从检查事件中删除一个项目

Answer 1

您可以使用 getTasks.Taken 访问 ListView 的 Items 源，因为它是静态的

并且您可以从实例化的 customcell 的 BindingContext 中获取项目

因此，现在您可以使用 IList 的 Remove 方法从 Items 源中删除一个项目

这是解决方案，请将 CustomCell 替换为以下代码

    public class CustomCell : ViewCell
    {
        public ObservableCollection<TaskViewModel> Taken { get; set; }
        public CustomCell()
        {
            Taken = new ObservableCollection<TaskViewModel>();
            StackLayout cell = new StackLayout()
            {
                HeightRequest = 120,
                HorizontalOptions = LayoutOptions.FillAndExpand,
                Orientation = StackOrientation.Horizontal,
                VerticalOptions = LayoutOptions.FillAndExpand,
                WidthRequest = 360,
            };
            StackLayout left = new StackLayout()
            {
                HorizontalOptions = LayoutOptions.CenterAndExpand,
                Orientation = StackOrientation.Vertical,
                VerticalOptions = LayoutOptions.Center,
            };
            Label name = new Label()
            {
                FontSize = 8,
                HorizontalOptions = LayoutOptions.Center,
                HorizontalTextAlignment = TextAlignment.Center,
                VerticalOptions = LayoutOptions.Center,
                VerticalTextAlignment = TextAlignment.Center,
            };

            Label team = new Label()
            {
                FontSize = 5,
                HorizontalOptions = LayoutOptions.Center,
                HorizontalTextAlignment = TextAlignment.Center,
                VerticalOptions = LayoutOptions.Center,
                VerticalTextAlignment = TextAlignment.Center,
            };
            Check check = new Check();
            check.DisplayStyle = CheckDisplayStyle.Default;
            check.HorizontalOptions = LayoutOptions.End;
            check.VerticalOptions = LayoutOptions.Center;

            check.Toggled += (s, e) =>
            {
                getTasks.Taken.Remove((s as Check).BindingContext as Taken);
            };

            //Set Binding
            name.SetBinding(Label.TextProperty, new Binding("Name"));
            team.SetBinding(Label.TextProperty, new Binding("Team"));
            View = cell;
            cell.Children.Add(left);
            left.Children.Add(name);
            left.Children.Add(team);
            cell.Children.Add(check);
        }
    }