lstNews.Items是页面上显示的对象列表.因此，此lstNews.Items是您的数据模板的集合，因此这就是为什么当您尝试lstNews.Items.Remove(lstNews.SelectedItem.ToString())时失败了.

lstNews.Items is list of object that are displayed on the page. So this lstNews.Items is collection of your datatemplate so that is why when you tried lstNews.Items.Remove(lstNews.SelectedItem.ToString()) than this fails.

您应该使用lstNews.Items.Remove(lstNews.SelectedItem)删除项目.

you should use lstNews.Items.Remove(lstNews.SelectedItem) to delete item.

但是为了***实践，***从源中而不是从列表中删除项目.即您应该从fulllist中删除项目，然后将其重新分配为lstNews.ItemsSource = fulllist;

But for best practice it is prefered to delete item from the source not from the list. i.e. You should delete item from fulllist and reassign it as lstNews.ItemsSource = fulllist;

您的代码中所做的更改

1. fulllist应该是 ObservableCollection ，以便对数据所做的所有更改都可以反映到UI. 将List转换为ObservableCollection可以使用以下代码:

1. fulllist should be a type of ObservableCollection so that all the changes done on data can be reflected to UI. To convert List to ObservableCollection Following code can be used:

fulllist = new ObservableCollection<NewsData>(new nList());

object obj = lstNews.SelectedItem;
if(obj is NewsData){
    fulllist.Remove((NewsData)obj);
    lstNews.ItemsSource = fulllist;
}