C＃WPF ListView无法正确删除项目

Question

我有一个看起来像这样的ListView ；

<Window x:Class="WPF_Viewer.URLLinks"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:WPF_Viewer"
    mc:Ignorable="d"
    Title="URLLinks" Height="461.215" Width="606.542" WindowStartupLocation="CenterScreen">
<Grid>
    <ListView x:Name="proxyListView" Loaded="proxyListView_Loaded">
        <ListView.ContextMenu>
            <ContextMenu Name="contextMenu1">
                <MenuItem Name="item1" Header="Delete" Click="item1_Click"/>
            </ContextMenu>
        </ListView.ContextMenu>
    </ListView>
</Grid>
</Window>

我正在尝试添加一个ContextMenu来删除SelectedItem 。

public partial class URLLinks : Window
{
    public URLLinks()
    {
        InitializeComponent();
    }

    private void proxyListView_Loaded(object sender, RoutedEventArgs e)
    {
        proxyListView.ItemsSource = GlobalVars.URLLinks;
    }

    private void item1_Click(object sender, RoutedEventArgs e)
    {
        GlobalVars.URLLinks.RemoveAt(proxyListView.SelectedIndex);
        ICollectionView view = CollectionViewSource.GetDefaultView(proxyListView.ItemsSource);
        //view.Refresh();
    }
}

有任何想法吗？

编辑：这是变量及其设置方式

public static async void GetLink(string url)
    {
        try
        {
            string sURL = url;
            Uri uri = new Uri(sURL);
            string host = uri.Host;
            using (HttpClient clientduplicate = new HttpClient())
            {
                clientduplicate.DefaultRequestHeaders.Add("User-Agent",
                    "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; WOW64; Trident / 6.0)");
                using (HttpResponseMessage responseduplicate = await clientduplicate.GetAsync(sURL))
                {
                    using (HttpContent contentduplicate = responseduplicate.Content)
                    {
                        try
                        {
                            string resultduplicate = await contentduplicate.ReadAsStringAsync();
                            var websiteduplicate = new HtmlAgilityPack.HtmlDocument();
                            websiteduplicate.LoadHtml(resultduplicate);
                            List<string> ListItems = new List<string>();
                            Settings.Default.Reload();
                            int maxLinks = Convert.ToInt32(Math.Round(Convert.ToDouble(Settings.Default["subLinksValue"]) * 10));

                            foreach (HtmlNode links in websiteduplicate.DocumentNode.SelectNodes("//a[@href]"))
                            {
                                HtmlAttribute att = links.Attributes["href"];
                                foreach (var link in att.Value.Split(' '))
                                {
                                    if (ListItems.Count >= maxLinks)
                                    {
                                        GlobalVars.URLLinks = ListItems;
                                        //File.WriteAllLines(AppDomain.CurrentDomain.BaseDirectory + @"\links.txt", ListItems.ToArray());
                                        return;
                                    }
                                    if (link.StartsWith("http") && link.Contains(host) && CheckURLValid(link))
                                    {
                                        ListItems.Add(link);
                                    }
                                }
                            }
                            GlobalVars.URLLinks = ListItems;
                            //File.WriteAllLines(AppDomain.CurrentDomain.BaseDirectory + @"\links.txt", ListItems.ToArray());
                            //return ListItems;
                        }
                        catch (Exception ex1)
                        {
                            Console.WriteLine("Error getting links");
                            //return null;
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            System.Windows.MessageBox.Show("Error, url not formatted correctly. Try coping your url from your browser");
        }
    }

Answer 1

即使您不打算走完整的MVVM路线，也至少要使用ObservableCollection的项，并为其分配ListView的ItemSource。 删除或添加项目时，这将自动更新控件。

试图在UI控件上执行业务逻辑操作将很快沦为一大堆意大利面条。

Answer 2

如果GlobalVars.URLLinks返回ObservableCollection<T>或实现INotifyCollectionChanged接口的任何其他自定义类型，则它将起作用：

private void item1_Click(object sender, RoutedEventArgs e)
{
    var ic = proxyListView.ItemsSource as IList<string>;
    ic.RemoveAt(proxyListView.SelectedIndex);
}

但是，如果在删除项目时，源集合没有引发更改通知（而List<T>没有），则在删除项目后，必须重新设置ItemsSource属性以刷新ListView ：

private void item1_Click(object sender, RoutedEventArgs e)
{
    GlobalVars.URLLinks.RemoveAt(proxyListView.SelectedIndex);
    proxyListView.ItemsSource = GlobalVars.URLLinks;
}

Answer 3

为了使它起作用，我唯一要做的就是将您的集合从List<string>更改为ObservableCollection<string> 。

完成此操作后，您无需重置列表视图上的项目。

static ObservableCollection<string> items = new ObservableCollection<string>() { "Item 1", "Item 2" };

private void proxyListView_Loaded(object sender, RoutedEventArgs e)
{
    proxyListView.ItemsSource = items;
}

private void item1_Click(object sender, RoutedEventArgs e)
{
    items.RemoveAt(proxyListView.SelectedIndex);
}