自动滚动列表视图到最后添加的项目的最佳方法是什么？

发布于 2024-07-18 06:55:53 字数 1448 浏览 9 评论 0原文

我使用 ListView 显示应用程序中发生的错误列表。它的行为和外观与 Visual Studio 中的错误列表完全相同。我想在选择最后一个错误项时添加自动滚动（就像当您将插入符号放在末尾时 Visual Studio 的日志窗口如何自动滚动）。

错误列表位于 ObservableCollection 中，它被传递到 ListView.ItemsSource，如下所示：

public ObservableCollection<ErrorListItem> Items;
... 
MyListView.ItemsSource = _Items;

我尝试在 _Items_CollectionChanged 中执行自动滚动> 事件处理程序，但因为这是 ItemsSource 上的事件，而不是实际的 ListViewItems 上的事件，所以很难确定是否选择了最后一个项目，因此选择新的项目这尤其困难，因为 ListViewItems 似乎不是立即创建的。我设法通过延迟调用来设置最后选择的项目来使其自动滚动，如下所示：

void _Items_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
    // determine the last item to select from 'e'
    ...        

    _ItemPendingToBeScrolled = newItemToSelect;
    ListView.SelectedItem = newItemToSelect;


    Dispatcher.BeginInvoke(DispatcherPriority.Background, 
        (ThreadStart)delegate 
        { 
            if (_ItemPendingToBeScrolled != null)
            {
                ListView.ScrollIntoView(_ItemPendingToBeScrolled);
                ItemPendingToBeScrolled = null;
            } 
        })
}

但这显然不是正确的方法。另外，如果列表被过滤，我希望事情继续工作（不检查源中的最后一项，而是检查 ListView 中的最后一个 ListViewItem）。

在添加到绑定集合后，将 ListViewItem 添加到 ListView 时，是否有办法侦听事件？为了正确地进行自动滚动，这将是捕获的理想事件。或者我可以使用另一种技术吗？

原文

I use a ListView to show a list of errors as they occur in my application. It behaves and looks exactly like the Error List in Visual Studio. I want to add auto-scrolling when the last error item is selected (like how Visual Studio's Log Window auto-scrolls when you place the caret at the end).

The list of errors is in an ObservableCollection, which is passed to the ListView.ItemsSource like this:

public ObservableCollection<ErrorListItem> Items;
... 
MyListView.ItemsSource = _Items;

I tried performing the auto-scroll in the _Items_CollectionChanged event handler, but because this is the event on the ItemsSource and not on the actual ListViewItems, it's a pain to figure out if the last item is selected, select the new row, etc. It's especially hard since it seems the ListViewItems are not created instantly. I managed to make it auto-scroll by delaying the call to set the last item selected like this:

void _Items_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
    // determine the last item to select from 'e'
    ...        

    _ItemPendingToBeScrolled = newItemToSelect;
    ListView.SelectedItem = newItemToSelect;


    Dispatcher.BeginInvoke(DispatcherPriority.Background, 
        (ThreadStart)delegate 
        { 
            if (_ItemPendingToBeScrolled != null)
            {
                ListView.ScrollIntoView(_ItemPendingToBeScrolled);
                ItemPendingToBeScrolled = null;
            } 
        })
}

But that's obviously not the right way to do it. Also, I want things to keep working if the list is filtered (not checking the last item in my source, but the last ListViewItem in the ListView).

Is there a way to listen to events when a ListViewItem gets added to the ListView following an addition to the bound collection? That would be the ideal event to capture in order to properly do my auto-scrolling. Or is there another technique I could use?

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