标签：rtt gen nts 选择 ret border idt etc can
操作需求场景：Listbox 高150 item 高150 listbox有几十个item ，希望鼠标滚轮滚动一次listbox 能滚动到下一个item，
代码实现：
<Grid x:Name="gd">
<Grid.RowDefinitions>
<RowDefinition Height="158" />
<RowDefinition />
</Grid.RowDefinitions>
<Grid Grid.Row="0" Name="firstrowgrid">
<ListBox ScrollViewer.PanningRatio="1" PreviewMouseWheel="waterfalllistbox_PreviewMouseWheel" ScrollViewer.ScrollChanged="waterfalllistbox_ScrollChanged" HorizontalAlignment="Stretch" ScrollViewer.CanContentScroll="False" SelectedIndex="{Binding Selectindex,Mode=TwoWay}" ScrollViewer.IsDeferredScrollingEnabled="False" SelectionChanged="waterfalllistbox_SelectionChanged" ScrollViewer.VerticalScrollBarVisibility="Visible" VirtualizingStackPanel.VirtualizationMode="Standard" VirtualizingStackPanel.IsVirtualizing="True" ItemsSource="{Binding WaterFallPoints2}" x:Name="waterfalllistbox">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Height="150">
<element:PtrRenderCompatible MouseDown="PtrRenderCompatible_MouseDown" Width="{Binding Width}" Height="150" PointItemsSource="{Binding DataPoints}" Brushes="{Binding BrushInfo}"/>
<TextBlock Text="{Binding StartTime}" Foreground="Blue" HorizontalAlignment="Left" VerticalAlignment="Top" FontSize="12"></TextBlock>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel Orientation="Vertical"></VirtualizingStackPanel>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
<Line x:Name="rline" MouseLeftButtonDown="rline_MouseLeftButtonDown" Visibility="Collapsed"></Line>
<Border Background="#ED9121" HorizontalAlignment="Right" VerticalAlignment="Top">
<StackPanel Width="60" Height="50">
<TextBlock TextAlignment="Center" Foreground="White" Text="选择导联:" Margin="0,2,0,2"></TextBlock>
<ComboBox ItemsSource="{Binding LeadList}" Mvc.Event="SelectionChanged" Mvc.Action="{Binding SelectLeadAction}" SelectedItem="{Binding WaterFallSelectedLead,Mode=TwoWay}">
</ComboBox>
</StackPanel>
</Border>
</Grid>
ui界面代码如上，重点是重写 waterfalllistbox_PreviewMouseWheel 鼠标滚轮事件
private void waterfalllistbox_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
e.Handled = true;
ScrollViewer obj = VisualHelper.FindChildren<ScrollViewer>(waterfalllistbox).First();
Debug.WriteLine("ScrollableHeight:" + obj.ScrollableHeight);
Debug.WriteLine("VerticalOffset:" + obj.VerticalOffset);
Debug.WriteLine("ContentVerticalOffset:" + obj.ContentVerticalOffset);
Debug.WriteLine("e.Delta:" + e.Delta);
if (e.Delta < 0)
{
obj.PageDown();//向下滚动
}
else
{
obj.PageUp();//
}
}
注意：item 的高度是150，由于listboxitem 有默认的外边距和内边距，所以listbox 所在的行的高度为158
这样的话 就能在竖向滑动的时候，可以一次滑动一个。
扩展：横向滑动的时候
ScrollViewer.PageLeft(), PageRight()
Listbox 鼠标滚动的时候默认调用的是
ScrollViewer.LineDown（）各个方向的line 方法；
在键盘按住上下箭头的时候默认调用pagedown 等各个方法。
(●‘?‘●) 打赏个包子也很赞奥
标签：rtt gen nts 选择 ret border idt etc can
原文地址：https://www.cnblogs.com/gisbeginner/p/10005864.html
