C# 防拖；滚动时下降

我正在做一个Wpf项目，但现在我被一个

ListView

问题绊住了

事实证明，我在ListView上实现了一个运行良好的

拖放功能。当我尝试向下或向上滚动时，问题就出现了。通过这样做，
拖放
功能被激活，防止我继续滚动

我发现这表明我们需要将控件附加到
ScrollChanged
事件

<ListView ScrollViewer.ScrollChanged="listView1_ScrollChanged"...

提前感谢。
如果您未处于MouseDown事件中，您可以阻止MouseMove事件：

bool stopDrag = true;
     private void listView1_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            // Store the mouse position
            startPoint = e.GetPosition(null);
stopDrag = false;
        }

        private void listView1_MouseMove(object sender, MouseEventArgs e)
        {
if(stopDrag)
   return;

            // Get the current mouse position
            Point mousePos = e.GetPosition(null);
            Vector diff = startPoint - mousePos;

            if (e.LeftButton == MouseButtonState.Pressed &&
                (Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragDistance ||
                Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragDistance))
            {
                // Get the dragged ListViewItem
                ListView listView = sender as ListView;

                // Get items to drag
                var a = listView.SelectedItems;

                // Initialize the drag & drop operation
                DataObject dragData = new DataObject("myFormat", a);
                DragDrop.DoDragDrop(listView, dragData, DragDropEffects.Move);
            } 
        }

private void listView1_MouseUp(...)
{
stopDrag = true;
}

这应该行得通，我是在浏览器中写的，所以如果我做错了什么，请原谅我的格式化，我希望您能理解。
我使用一种简单的方法来确认是否使用
系统参数确认拖动操作。最小水平拖动距离
和
系统参数。最小垂直拖动距离
，用于此目的：

private bool IsDragConfirmed(Point point)
{
    bool horizontalMovement = Math.Abs(point.X - dragStartPosition.X) > 
         SystemParameters.MinimumHorizontalDragDistance;
    bool verticalMovement = Math.Abs(point.Y - dragStartPosition.Y) > 
         SystemParameters.MinimumVerticalDragDistance;
    return (horizontalMovement | verticalMovement);
}

它在
PreviewMouseMove
事件中调用。。。以下是一个简化的示例：

private void DragSourcePreviewMouseMove(object sender, MouseEventArgs e)
{
    if (isMouseDown && IsDragConfirmed(e.GetPosition(sender as ListBox)))
    {
        // Start your drag operation here
    }
}

我得到了与下面答案相同的问题和来源。
我已经决定，如果鼠标位置不在listview项（rect 0，0，lv.width-scroll.width，lv.height-scroll.height）上，就防止拖动
所以我有一个“allowdrag”标志，当PreviewMouseLeftButtonDown运行时，如果鼠标指针在必需的rect上，则该标志变为真

VB.NET

Private allowdrag As Boolean

Private Sub lv_PreviewMouseLeftButtonDown(sender As Object, e As MouseButtonEventArgs) Handles lvAttributesDefault.PreviewMouseLeftButtonDown
    Dim listView As ListView = TryCast(sender, ListView)
    allowdrag = e.GetPosition(sender).X < listView.ActualWidth - SystemParameters.VerticalScrollBarWidth And e.GetPosition(sender).Y < listView.ActualHeight - SystemParameters.HorizontalScrollBarHeight
End Sub

Private Sub lv_MouseMove(sender As Object, e As MouseEventArgs) Handles lvAttributesDefault.MouseMove
    Dim listView As ListView = TryCast(sender, ListView)

    If e.LeftButton = MouseButtonState.Pressed And listView.SelectedItem IsNot Nothing And allowdrag Then
        Dim obj As clsAttribute = CType(listView.SelectedItem, clsAttribute)
        Dim dragData As New DataObject("clsAttribute", obj)

        DragDrop.DoDragDrop(listView, dragData, DragDropEffects.Copy)
    End If
End Sub

Private allowdrag作为布尔值
私有子lv_PreviewMouseLeftButtonDown（发送者作为对象，e作为鼠标按钮ventargs）处理lvAttributesDefault.PreviewMouseLeftButtonDown
将listView设置为listView=TryCast（发送方，listView）
allowdrag=e.GetPosition（发送方）.X

C#（电传码转换器）

private bool allowdrag；
私有void lv_PreviewMouseLeftButtonDown（对象发送器，鼠标按钮ventargs e）
{
ListView ListView=发件人作为ListView；
allowdrag=e.GetPosition（发送方）。X

PS.ClsaAttribute是我的自定义类。这个
listview已绑定到ObservableCollection（属于CLSATAttribute）
如果您能告诉我们您是如何实现拖放功能的。@Georgi it Code Adddhi，我刚刚尝试过，但它不起作用，它一直以同样的方式运行：（理论上，如果你调试它并给我一些额外的信息，它应该可以工作。）我这样做了，这里的问题是当我按下鼠标左键时，
stopDrag
变成
false
，因此，当它得到
listView1\u MouseMove
方法时，条件
if（stopDrag）return
不满足。我可以反转条件，但这样做，拖放功能就永远不会启动，因为我的拖放功能是在获取鼠标位置的
PreviewMouseLeftButtonDown
事件中启动的
Private allowdrag As Boolean

Private Sub lv_PreviewMouseLeftButtonDown(sender As Object, e As MouseButtonEventArgs) Handles lvAttributesDefault.PreviewMouseLeftButtonDown
    Dim listView As ListView = TryCast(sender, ListView)
    allowdrag = e.GetPosition(sender).X < listView.ActualWidth - SystemParameters.VerticalScrollBarWidth And e.GetPosition(sender).Y < listView.ActualHeight - SystemParameters.HorizontalScrollBarHeight
End Sub

Private Sub lv_MouseMove(sender As Object, e As MouseEventArgs) Handles lvAttributesDefault.MouseMove
    Dim listView As ListView = TryCast(sender, ListView)

    If e.LeftButton = MouseButtonState.Pressed And listView.SelectedItem IsNot Nothing And allowdrag Then
        Dim obj As clsAttribute = CType(listView.SelectedItem, clsAttribute)
        Dim dragData As New DataObject("clsAttribute", obj)

        DragDrop.DoDragDrop(listView, dragData, DragDropEffects.Copy)
    End If
End Sub

private bool allowdrag;
private void lv_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    ListView listView = sender as ListView;
    allowdrag = e.GetPosition(sender).X < listView.ActualWidth - SystemParameters.VerticalScrollBarWidth & e.GetPosition(sender).Y < listView.ActualHeight - SystemParameters.HorizontalScrollBarHeight;
}

private void lv_MouseMove(object sender, MouseEventArgs e)
{
    ListView listView = sender as ListView;

    if (e.LeftButton == MouseButtonState.Pressed & listView.SelectedItem != null & allowdrag) {
        clsAttribute obj = (clsAttribute)listView.SelectedItem;
        DataObject dragData = new DataObject("clsAttribute", obj);

        DragDrop.DoDragDrop(listView, dragData, DragDropEffects.Copy);
    }
}